MeSH Semantic Type: Amino Acid, Peptide, or Protein [T116]

(131)I-Macroaggregated Albumin [M0019694]

1,4-alpha-Glucan Branching Enzyme [M0023173]
In glycogen or amylopectin synthesis, the enzyme that catalyzes the transfer of a segment of a 1,4-alpha-glucan chain to a primary hydroxy group in a similar glucan chain. EC 2.4.1.18.

1-Acylglycerol Phosphate Acyltransferase 2 [M0460552]

1-Acylglycerol-3-Phosphate O-Acyltransferase [M0070640]
An enzyme that catalyzes the acyl group transfer of ACYL COA to 1-acyl-sn-glycerol 3-phosphate to generate 1,2-diacyl-sn-glycerol 3-phosphate. This enzyme has alpha, beta, gamma, delta and epsilon subunits.

1-Acylglycerophosphocholine O-Acyltransferase [M0012841]
An enzyme localized predominantly within the plasma membrane of lymphocytes. It catalyzes the transfer of long-chain fatty acids, preferentially unsaturated fatty acids, to lysophosphatides with the formation of 1,2-diacylglycero-3-phosphocholine and CoA. EC 2.3.1.23.

1-Alkyl-2-acetylglycerophosphocholine Esterase [M0118406]
A lipoprotein-associated PHOSPHOLIPASE A2 which modulates the action of PLATELET ACTIVATING FACTOR by hydrolyzing the SN-2 ester bond to yield the biologically inactive lyso-platelet-activating factor. It has specificity for phospholipid substrates with short-chain residues at the SN-2 position, but inactive against long-chain phospholipids. Deficiency in this enzyme is associated with many diseases including ASTHMA, and HYPERCHOLESTEROLEMIA.

1-Carboxyglutamic Acid [M0023166]
Found in various tissues, particularly in four blood-clotting proteins including prothrombin, in kidney protein, in bone protein, and in the protein present in various ectopic calcifications.

1-Palmitylglycerol 3-Phosphate Acyltransferase [M0070635]

1-Phosphatidylinositol 3-Kinase [M0029501]
An enzyme that catalyzes the conversion of phosphatidylinositol to phosphatidylinositol 3-phosphate. This is the first committed step in the biosynthesis of phosphatidylinositol 3,4-bisphosphate and phosphatidylinositol 3,4,5-trisphosphate. This pathway is thought to play a critical role in DNA repair, V(D)J recombination and cell cycle checkpoints. EC 2.7.1.137.

1-Phosphatidylinositol 4-Kinase [M0029506]
An enzyme that catalyzes the conversion of phosphatidylinositol (PHOSPHATIDYLINOSITOLS) to phosphatidylinositol 4-phosphate, the first committed step in the biosynthesis of phosphatidylinositol 4,5-bisphosphate.

1-Pyrroline-5-Carboxylate Dehydrogenase [M0092808]
An enzyme that catalyzes the oxidation of 1-pyrroline-5-carboxylate to L-GLUTAMATE in the presence of NAD. Defects in the enzyme are the cause of hyperprolinemia II.

1-Sarcosine-8-Isoleucine Angiotensin II [M0023171]
An ANGIOTENSIN II analog which acts as a highly specific inhibitor of ANGIOTENSIN TYPE 1 RECEPTOR.

11-beta-Hydroxysteroid Dehydrogenase Type 1 [M0337947]
A low-affinity 11 beta-hydroxysteroid dehydrogenase found in a variety of tissues, most notably in LIVER; LUNG; ADIPOSE TISSUE; vascular tissue; OVARY; and the CENTRAL NERVOUS SYSTEM. The enzyme acts reversibly and can use either NAD or NADP as cofactors.

11-beta-Hydroxysteroid Dehydrogenase Type 2 [M0076299]
An high-affinity, NAD-dependent 11-beta-hydroxysteroid dehydrogenase that acts unidirectionally to catalyze the dehydrogenation of CORTISOL to CORTISONE. It is found predominantly in mineralocorticoid target tissues such as the KIDNEY; COLON; SWEAT GLANDS; and the PLACENTA. Absence of the enzyme leads to a fatal form of childhood hypertension termed, APPARENT MINERALOCORTICOID EXCESS SYNDROME.

11-beta-Hydroxysteroid Dehydrogenases [M0076306]
Hydroxysteroid dehydrogenases that catalyzes the reversible conversion of CORTISOL to the inactive metabolite CORTISONE. Enzymes in this class can utilize either NAD or NADP as cofactors.

14-3-3 Protein, beta Isoform [M0439853]

14-3-3 Protein, epsilon Isoform [M0363270]

14-3-3 Protein, eta Isoform [M0439854]

14-3-3 Protein, gamma Isoform [M0091234]

14-3-3 Protein, tau Isoform [M0091236]

14-3-3 Protein, zeta Isoform [M0091237]

14-3-3 Proteins [M0091246]
A large family of signal-transducing adaptor proteins present in wide variety of eukaryotes. They are PHOSPHOSERINE and PHOSPHOTHREONINE binding proteins involved in important cellular processes including SIGNAL TRANSDUCTION; CELL-CYCLE control; APOPTOSIS; and cellular stress responses. 14-3-3 proteins function by interacting with other signal-transducing proteins and effecting changes in their enzymatic activity and subcellular localization. The name 14-3-3 derives from numerical designations used in the original fractionation patterns of the proteins.

15-Ketosteryl Oleate Hydrolase [M0004272]

15-Oxoprostaglandin 13-Reductase [M0017804]
(5Z)-(15S)-11 alpha-Hydroxy-9,15-dioxoprostanoate:NAD(P)+ delta(13)-oxidoreductase. An enzyme active in prostaglandin E and F catabolism. It catalyzes the reduction of the double bond at the 13-14 position of the 15-ketoprostaglandins and uses NADPH as cofactor. EC 1.3.1.48.

17 alpha-Hydroxyprogesterone Aldolase [M0028873]

17 beta, 20 alpha-Hydroxysteroid Dehydrogenase [M0105215]

17 beta-Hydroxysteroid Dehydrogenases [M0023178]

17 beta-Hydroxysteroid UDP-Glucuronosyltransferase [M0022214]

17-Hydroxysteroid Dehydrogenases [M0023179]
A class of enzymes that catalyzes the oxidation of 17-hydroxysteroids to 17-ketosteroids. EC 1.1.-.

2',3'-Cyclic-Nucleotide Phosphodiesterases [M0023206]
Nucleoside-2',3'-cyclic phosphate nucleotidohydrolase. Enzymes that catalyze the hydrolysis of the 2'- or 3'- phosphate bonds of 2',3'-cyclic nucleotides. Also hydrolyzes nucleoside monophosphates. Includes EC 3.1.4.16 and EC 3.1.4.37. EC 3.1.4.-.

2',5'-Oligoadenylate Synthetase [M0023207]
An enzyme that catalyzes the conversion of ATP into a series of (2'-5') linked oligoadenylates and pyrophosphate in the presence of double-stranded RNA. These oligonucleotides activate an endoribonuclease (RNase L) which cleaves single-stranded RNA. Interferons can act as inducers of these reactions. EC 2.7.7.-.

2'-P-ADPR Cyclase [M0259134]

2-Acetolactate Mutase [M0023185]
An enzyme involved in the biosynthesis of isoleucine and valine. It converts 2-acetolactate into 3-hydroxy-2-oxo-isovalerate. Also acts on 2-hydroxy-2-acetobutyrate to form 2-hydroxy-2-oxo-3-methylvalerate. EC 5.4.99.3.

2-Amino-5-phosphonovalerate [M0024150]
The D-enantiomer is a potent and specific antagonist of NMDA glutamate receptors (RECEPTORS, N-METHYL-D-ASPARTATE). The L form is inactive at NMDA receptors but may affect the AP4 (2-amino-4-phosphonobutyrate; APB) excitatory amino acid receptors.

2-Aminoadipate Transaminase [M0113522]
A PYRIDOXAL PHOSPHATE containing enzyme that catalyzes the transfer of amino group of L-2-aminoadipate onto 2-OXOGLUTARATE to generate 2-oxoadipate and L-GLUTAMATE.

2-Aminoadipic Acid [M0023188]
A metabolite in the principal biochemical pathway of lysine. It antagonizes neuroexcitatory activity modulated by the glutamate receptor, N-METHYL-D-ASPARTATE; (NMDA).

2-Isopropylmalate Synthase [M0023192]
An enzyme that catalyzes the first step in the biosynthetic pathway to LEUCINE, forming isopropyl malate from acetyl-CoA and alpha-ketoisovaleric acid. This enzyme was formerly listed as EC 4.1.3.12.

2-Oxoisovalerate Dehydrogenase (Acylating) [M0077427]
An NAD+ dependent enzyme that catalyzes the oxidation 3-methyl-2-oxobutanoate to 2-methylpropanoyl-CoA. It plays a role in the degradation of VALINE; LEUCINE; and ISOLEUCINE.

20-alpha-Hydroxysteroid Dehydrogenase [M0023209]
An enzymes that catalyzes the reversible reduction-oxidation reaction of 20-alpha-hydroxysteroids, such as from PROGESTERONE to 20-ALPHA-DIHYDROPROGESTERONE.

20-Hydroxysteroid Dehydrogenases [M0023208]
A group of enzymes that catalyze the reversible reduction-oxidation reaction of 20-hydroxysteroids, such as from a 20-ketosteroid to a 20-alpha-hydroxysteroid (EC 1.1.1.149) or to a 20-beta-hydroxysteroid (EC 1.1.1.53).

25-Hydroxyvitamin D3 1-alpha-Hydroxylase [M0023210]
A mitochondrial cytochrome P450 enzyme that catalyzes the 1-alpha-hydroxylation of 25-hydroxyvitamin D3 (also known as 25-hydroxycholecalciferol) in the presence of molecular oxygen and NADPH-FERRIHEMOPROTEIN REDUCTASE. This enzyme, encoded by CYP27B1 gene, converts 25-hydroxyvitamin D3 to 1-alpha,25-dihydroxyvitamin D3 which is the active form of VITAMIN D in regulating bone growth and calcium metabolism. This enzyme is also active on plant 25-hydroxyvitamin D2 (ergocalciferol).

3 alpha,20 beta Hydroxysteroid Dehydrogenase [M0005220]

3',5'-Cyclic-GMP Phosphodiesterase [M0023237]
An enzyme that catalyzes the hydrolysis of cyclic GMP to yield guanosine-5'-phosphate. EC 3.1.4.35.

3',5'-Cyclic-Nucleotide Phosphodiesterase [M0023233]
An enzyme that catalyzes the hydrolysis of cyclic AMP to form adenosine 5'-phosphate. The enzyme is widely distributed in animal tissue and controls the level of intracellular cyclic AMP. Also acts on 3',5'-cyclic IMP and 3',5'-cyclic GMP. EC 3.1.4.17.

3'-5'-Exonucleases [M0082739]

3'-orf Protein [M0024066]

3,4-Dihydroxyphenylserine [M0023230]

3-alpha-Hydroxysteroid Dehydrogenase (B-Specific) [M0076298]
A 3-hydroxysteroid dehydrogenase which catalyzes the reversible reduction of the active androgen, DIHYDROTESTOSTERONE to 5 ALPHA-ANDROSTANE-3 ALPHA,17 BETA-DIOL. It also has activity towards other 3-alpha-hydroxysteroids and on 9-, 11- and 15- hydroxyprostaglandins. The enzyme is B-specific in reference to the orientation of reduced NAD or NADPH.

3-Deoxy-7-Phosphoheptulonate Synthase [M0016655]
An enzyme that catalyzes the formation of 7-phospho-2-keto-3-deoxy-D-arabinoheptonate from phosphoenolpyruvate and D-erythrose-4-phosphate. It is one of the first enzymes in the biosynthesis of TYROSINE and PHENYLALANINE. This enzyme was formerly listed as EC 4.1.2.15.

3-Fucosyl-N-acetyl-lactosamine [M0024835]

3-Fucosyllactosamine Determinant [M0024831]

3-Hydroxyacyl CoA Dehydrogenases [M0023215]
Enzymes that reversibly catalyze the oxidation of a 3-hydroxyacyl CoA to 3-ketoacyl CoA in the presence of NAD. They are key enzymes in the oxidation of fatty acids and in mitochondrial fatty acid synthesis. EC 1.1.1.35.

3-Hydroxyanthranilate 3,4-Dioxygenase [M0076197]
An enzyme that catalyzes the conversion of 3-hydroxyanthranilate to 2-amino-3-carboxymuconate semialdehyde. It was formerly characterized as EC 1.13.1.6.

3-Hydroxysteroid Dehydrogenases [M0023219]
Catalyze the oxidation of 3-hydroxysteroids to 3-ketosteroids.

3-Isopropylmalate Dehydrogenase [M0076384]
An NAD+ dependent enzyme that catalyzes the oxidation of 3-carboxy-2-hydroxy-4-methylpentanoate to 3-carboxy-4-methyl-2-oxopentanoate. It is involved in the biosynthesis of VALINE; LEUCINE; and ISOLEUCINE.

3-Methyl-2-Oxobutanoate Dehydrogenase (Lipoamide) [M0077442]
A ketone oxidoreductase that catalyzes the overall conversion of alpha-keto acids to ACYL-CoA and CO2. The enzyme requires THIAMINE DIPHOSPHATE as a cofactor. Defects in genes that code for subunits of the enzyme are a cause of MAPLE SYRUP URINE DISEASE. The enzyme was formerly classified as EC 1.2.4.3.

3-Oxoacyl-(Acyl-Carrier-Protein) Synthase [M0023223]
An enzyme of long-chain fatty acid synthesis, that adds a two-carbon unit from malonyl-(acyl carrier protein) to another molecule of fatty acyl-(acyl carrier protein), giving a beta-ketoacyl-(acyl carrier protein) with the release of carbon dioxide. EC 2.3.1.41.

3-Phosphoshikimate 1-Carboxyvinyltransferase [M0079972]
An enzyme of the shikimate pathway of AROMATIC AMINO ACID biosynthesis, it generates 5-enolpyruvylshikimate 3-phosphate and ORTHOPHOSPHATE from PHOSPHOENOLPYRUVATE and SHIKIMATE-3-PHOSPHATE. The shikimate pathway is present in BACTERIA and PLANTS but not in MAMMALS.

4-1BB Ligand [M0291679]
A membrane bound member of the TNF superfamily that is expressed on activated B-LYMPHOCYTES; MACROPHAGES; and DENDRITIC CELLS. The ligand is specific for the 4-1BB RECEPTOR and may play a role in inducing the proliferation of activated peripheral blood T-LYMPHOCYTES.

4-Aminobutyrate Transaminase [M0000939]
An enzyme that converts brain gamma-aminobutyric acid (GAMMA-AMINOBUTYRIC ACID) into succinate semialdehyde, which can be converted to succinic acid and enter the citric acid cycle. It also acts on beta-alanine. EC 2.6.1.19.

4-Fluorophenylalanine [M0015726]

4-Hydroxybenzoate-3-Monooxygenase [M0023240]
A flavoprotein that catalyzes the synthesis of protocatechuic acid from 4-hydroxybenzoate in the presence of molecular oxygen. EC 1.14.13.2.

4-Hydroxyphenylpyruvate Dioxygenase [M0023242]
An enzyme that catalyzes the conversion of 4-hydroxyphenylpyruvate plus oxygen to homogentisic acid and carbon dioxide. EC 1.13.11.27.

4-Hydroxyproline [M0010779]

4-Nitrophenol-UDP-Glucuronosyltransferase [M0022215]

4-Nitrophenylphosphatase [M0014913]
An enzyme that catalyzes the hydrolysis of nitrophenyl phosphates to nitrophenols. At acid pH it is probably ACID PHOSPHATASE (EC 3.1.3.2); at alkaline pH it is probably ALKALINE PHOSPHATASE (EC 3.1.3.1). EC 3.1.3.41.

5 alpha-Dihydroprogesterone 3 alpha-Hydroxysteroid Oxidoreductase [M0090285]

5'-3'-Exonucleases [M0445300]

5'-Nucleotidase [M0024108]
A glycoprotein enzyme present in various organs and in many cells. The enzyme catalyzes the hydrolysis of a 5'-ribonucleotide to a ribonucleoside and orthophosphate in the presence of water. It is cation-dependent and exists in a membrane-bound and soluble form. EC 3.1.3.5.

5,10-Methylenetetrahydrofolate Reductase (FADH2) [M0076715]
An FAD-dependent oxidoreductase found primarily in BACTERIA. It is specific for the reduction of 5,10-methylenetetrahydrofolate to 5-methyltetrahydrofolate. This enzyme was formerly listed as EC 1.1.1.68 and 1.1.99.15.

5-Aminolaevulinate [M0000952]

5-Aminolevulinate Synthetase [M0000954]
An enzyme of the transferase class that catalyzes condensation of the succinyl group from succinyl coenzyme A with glycine to form delta-aminolevulinate. It is a pyridoxyal phosphate protein and the reaction occurs in mitochondria as the first step of the heme biosynthetic pathway. The enzyme is a key regulatory enzyme in heme biosynthesis. In liver feedback is inhibited by heme. EC 2.3.1.37.

5-Aminosalicylate [M0029385]

5-Fluoro-2'-deoxyuridine Phosphorylase [M0022358]

5-HT(1Dalpha) Receptor [M0448576]

5-Hydroxytryptophan [M0010787]
The immediate precursor in the biosynthesis of SEROTONIN from tryptophan. It is used as an antiepileptic and antidepressant.

5-Methyltetrahydrofolate-Homocysteine S-Methyltransferase [M0021236]
An enzyme that catalyzes the formation of methionine by transfer of a methyl group from 5-methyltetrahydrofolate to homocysteine. It requires a cobamide coenzyme. The enzyme can act on mono- or triglutamate derivatives. EC 2.1.1.13.

6-Aminocaproic Acid [M0023260]
An antifibrinolytic agent that acts by inhibiting plasminogen activators which have fibrinolytic properties.

6-Deoxyerythronolide-B Synthase [M0324448]

6-Phosphofructo-2-kinase-fructose-2,6-bisphosphatase [M0166748]

6-Phytase [M0016817]
An enzyme that catalyzes the conversion of myo-inositol hexakisphosphate and water to 1L-myo-inositol 1,2,3,4,5-pentakisphosphate and orthophosphate. EC 3.1.3.26.

7-Alkoxycoumarin O-Dealkylase [M0023999]
A drug-metabolizing enzyme found in the hepatic, placental and intestinal microsomes that metabolizes 7-alkoxycoumarin to 7-hydroxycoumarin. The enzyme is cytochrome P-450- dependent.

7-Hydroxycoumarin UDP Glucuronyltransferase [M0022216]

70Z-Cbl Protein [M0477402]

7S Collagen [M0004772]
A stable peptide fragment originating from the N-terminal domain of collagen type IV.

9,10-Epoxypalmitic Acid Hydrase [M0007609]

9-cis-Halorhodopsin [M0375050]

99mTc-Albures [M0353697]

99mTc-Human Serum Albumin [M0021097]

A gamma-Globin [M0009279]

A-43818 [M0369307]

AB-Vancomycin [M0476497]

Abbokinase [M0333864]

Abbott-38579 [M0373097]

Abrin [M0000055]
A toxic lectin from the seeds of jequirity, Abrus precatorius L. Very active poison. Five different proteins have so far been isolated: Abrus agglutinin, the component responsible for: hemagglutinating activity, & abrins a-d, the toxic principals each consisting of two peptide chains are held together by disulfide bonds.

Abrin A [M0000056]

Abrin C [M0000057]

Abuf�ne [M0431875]

Ac-De [M0484999]

Accent [M0373242]

acebraus [M0445735]

Acemuc [M0444760]

Acetabs [M0445736]

Acetaminophen Sulphotransferase [M0023427]

Acetate Kinase [M0000124]
An enzyme that catalyzes reversibly the phosphorylation of acetate in the presence of a divalent cation and ATP with the formation of acetylphosphate and ADP. It is important in the glycolysis process. EC 2.7.2.1.

Acetate-CoA Ligase [M0000159]
An enzyme that catalyzes the formation of CoA derivatives from ATP, acetate, and CoA to form AMP, pyrophosphate, and acetyl CoA. It acts also on propionates and acrylates. EC 6.2.1.1.

Acetohydroxyacid Synthetase I [M0000139]

Acetoin Dehydrogenase [M0000138]
An enzyme that catalyzes the conversion of acetoin to diacetyl in the presence of NAD. EC 1.1.1.5.

Acetolactate Synthase [M0000140]
A flavoprotein enzyme that catalyzes the formation of acetolactate from 2 moles of PYRUVATE in the biosynthesis of VALINE and the formation of acetohydroxybutyrate from pyruvate and alpha-ketobutyrate in the biosynthesis of ISOLEUCINE. This enzyme was formerly listed as EC 4.1.3.18.

Acetoxyhydroxyacid Synthase III [M0000141]

Acetyl-CoA C-Acetyltransferase [M0000153]
An enzyme that catalyzes the formation of acetoacetyl-CoA from two molecules of ACETYL COA. Some enzymes called thiolase or thiolase-I have referred to this activity or to the activity of ACETYL-COA C-ACYLTRANSFERASE.

Acetyl-CoA C-Acyltransferase [M0000155]
Enzyme that catalyzes the final step of fatty acid oxidation in which ACETYL COA is released and the CoA ester of a fatty acid two carbons shorter is formed.

Acetyl-CoA Carboxylase [M0000156]
A carboxylating enzyme that catalyzes the conversion of ATP, acetyl-CoA, and HCO3- to ADP, orthophosphate, and malonyl-CoA. It is a biotinyl-protein that also catalyzes transcarboxylation. The plant enzyme also carboxylates propanoyl-CoA and butanoyl-CoA (From Enzyme Nomenclature, 1992) EC 6.4.1.2.

Acetyl-CoA Hydrolase [M0000157]
An enzyme that catalyzes reversibly the hydrolysis of acetyl-CoA to yield CoA and acetate. The enzyme is involved in the oxidation of fatty acids. EC 3.1.2.1.

Acetylated, Dephosphorylated beta-Casein [M0003585]

Acetylcholinesterase [M0000169]
An enzyme that catalyzes the hydrolysis of ACETYLCHOLINE to CHOLINE and acetate. In the CNS, this enzyme plays a role in the function of peripheral neuromuscular junctions. EC 3.1.1.7.

Acetylcystein AL [M0445728]

Acetylcystein Atid [M0445737]

Acetylcystein Heumann [M0445739]

Acetylcystein Trom [M0445740]

Acetylcysteine [M0000171]
The N-acetyl derivative of CYSTEINE. It is used as a mucolytic agent to reduce the viscosity of mucous secretions. It has also been shown to have antiviral effects in patients with HIV due to inhibition of viral stimulation by reactive oxygen intermediates.

Ac�tylcyst�ine GNR [M0445979]

Acetylcysteine Hydrochloride [M0331337]

Acetylcysteine Sodium [M0331341]

Acetylcysteine Zinc [M0331336]

Acetylcysteine, (D)-Isomer [M0331339]

Acetylcysteine, (DL)-Isomer [M0331342]

Acetylcysteine, Monoammonium Salt [M0331340]

Acetylcysteine, Monosodium Salt [M0331338]

Acetylesterase [M0000187]
An enzyme that catalyzes the conversion of acetate esters and water to alcohols and acetate. EC 3.1.1.6.

Acetylglucosaminidase [M0000190]
2-Acetamido-2-deoxy-beta-D-glucoside acetamidodeoxygluco-hydrolase. Catalyzes the hydrolysis of terminal, non-reducing 2-acetamido-2-deoxy-beta-glucose residues in chitobiose and higher analogs as well as in glycoproteins. Has been used widely in structural studies on bacterial cell walls and in the study of diseases such as mucolipidosis and various inflammatory disorders of muscle and connective tissue.

Acetylmuramyl-Alanyl-Isoglutamine [M0000191]
Peptidoglycan immunoadjuvant originally isolated from bacterial cell wall fragments; also acts as pyrogen and may cause arthritis; stimulates both humoral and cellular immunity.

Acetylserotonin N-Methyltransferase [M0000195]
An enzyme that catalyzes the transfer of a methyl group from S-adenosylmethionine to N-acetylserotonin to form N-acetyl-5-methoxytryptamine (MELATONIN). EC 2.1.1.4.

Acetylthiocholinesterase [M0000170]

Acetyltransferases [M0000197]
Enzymes catalyzing the transfer of an acetyl group, usually from acetyl coenzyme A, to another compound. EC 2.3.1.

Acetyst [M0445741]

Acid Anhydride Hydrolases [M0026851]
A group of enzymes that catalyze the hydrolysis of diphosphate bonds in compounds such as nucleoside di- and tri-phosphates, and sulfonyl-containing anhydrides such as adenylylsulfate. (Enzyme Nomenclature, 1992) EC 3.6.

Acid beta-Glycerophosphatase [M0000209]

Acid DNase [M0006012]

Acid Lipase [M0012539]

Acid Lipase A [M0012540]

Acid Lipase B [M0012541]

Acid Lipase I [M0012542]

Acid Lipase II [M0012543]

Acid Phosphatase [M0000208]
An enzyme that catalyzes the conversion of an orthophosphoric monoester and water to an alcohol and orthophosphate. EC 3.1.3.2.

Acid Proteases [M0024884]

Acid Ribonuclease [M0019068]

Acid Thiol Proteinase [M0005541]

Acidic Pancreatic Trypsin Inhibitor [M0022082]

Acidin-Pepsin [M0002434]

Acignost [M0016167]

Aconitate Hydratase [M0000233]
An enzyme that catalyzes the reversible hydration of cis-aconitate to yield citrate or isocitrate. It is one of the citric acid cycle enzymes. EC 4.2.1.3.

Acrosin [M0000265]
A trypsin-like enzyme of spermatozoa which is not inhibited by alpha 1 antitrypsin.

ACTH (1-13) [M0493893]

ACTH (1-13)NH2 [M0493894]

ACTHalpha(18-39), Serine(31)- [M0066245]

Actilyse [M0016992]

Actin Capping Proteins [M0091213]
Actin capping proteins are cytoskeletal proteins that bind to the ends of ACTIN FILAMENTS to regulate actin polymerization.

Actin Depolymerizing Factors [M0128858]
A family of low MOLECULAR WEIGHT actin-binding proteins found throughout eukaryotes. They remodel the actin CYTOSKELETON by severing ACTIN FILAMENTS and increasing the rate of monomer dissociation.

Actin-Binding Proteins [M0013780]

Actin-Related Protein 2 [M0292308]
A PROFILIN binding domain protein that is part of the Arp2-3 complex. It is related in sequence and structure to ACTIN and binds ATP.

Actin-Related Protein 2-3 Complex [M0480284]
A complex of seven proteins including ARP2 PROTEIN and ARP3 PROTEIN that plays an essential role in maintenance and assembly of the CYTOSKELETON. Arp2-3 complex binds WASP PROTEIN and existing ACTIN FILAMENTS, and it nucleates the formation of new branch point filaments.

Actin-Related Protein 3 [M0292311]
A component of the Arp2-3 complex that is related in sequence and structure to ACTIN and that binds ATP. It is expressed at higher levels than ARP2 PROTEIN and does not contain a PROFILIN binding domain.

Actinin [M0000275]
A protein factor that regulates the length of R-actin. It is chemically similar, but immunochemically distinguishable from actin.

Actinomycin [M0005643]

Actins [M0000296]
Filamentous proteins that are the main constituent of the thin filaments of muscle fibers. The filaments (known also as filamentous or F-actin) can be dissociated into their globular subunits; each subunit is composed of a single polypeptide 375 amino acids long. This is known as globular or G-actin. In conjunction with MYOSINS, actin is responsible for the contraction and relaxation of muscle.

Activase [M0333862]

Activated-Leukocyte Cell Adhesion Molecule [M0030062]
Cell adhesion molecule expressed on activated leukocytes, fibroblasts, and neurons. It is a ligand for CD6. ALCAM-CD6 interactions may play a role in the binding of T and B cells to activated leukocytes.

Activating Transcription Factor 1 [M0214756]
An activating transcription factor that regulates expression of a variety of genes including C-JUN GENES and TRANSFORMING GROWTH FACTOR BETA2.

Activating Transcription Factor 2 [M0213650]
An activating transcription factor that regulates expression of a variety of GENES including C-JUN GENES; CYCLIN A; CYCLIN D1; and ACTIVATING TRANSCRIPTION FACTOR 3.

Activating Transcription Factor 3 [M0229742]
An activating transcription factor that plays a key role in cellular responses to GENOTOXIC STRESS and OXIDATIVE STRESS.

Activating Transcription Factor 4 [M0194959]
An activating transcription factor that regulates the expression of a variety of GENES involved in amino acid metabolism and transport. It also interacts with HTLV-I TRANS-ACTIVATOR PROTEIN.

Activating Transcription Factor 6 [M0280604]
One of the BASIC-LEUCINE ZIPPER TRANSCRIPTION FACTORS that is synthesized as a membrane-bound protein in the ENDOPLASMIC RETICULUM. In response to endoplasmic reticulum stress it translocates to the GOLGI APPARATUS. It is activated by PROTEASES and then moves to the CELL NUCLEUS to regulate GENETIC TRANSCRIPTION of GENES involved in the unfolded protein response.

Activating Transcription Factors [M0481519]
Activating transcription factors were originally identified as DNA-BINDING PROTEINS that interact with EARLY PROMOTERS from ADENOVIRUSES. They are a family of basic leucine zipper transcription factors that bind to the consensus site TGACGTCA of the cyclic AMP response element, and are closely related to CYCLIC AMP-RESPONSIVE DNA-BINDING PROTEIN.

Activin Receptors [M0229093]
Receptors for ACTIVINS are membrane protein kinases belonging to the family of PROTEIN-SERINE-THREONINE KINASES, thus also named activin receptor-like kinases (ALK's). Activin receptors also bind TRANSFORMING GROWTH FACTOR BETA. As those transmembrane receptors of the TGF-beta superfamily (RECEPTORS, TRANSFORMING GROWTH FACTOR BETA), ALK's consist of two different but related protein kinases, Type I and Type II. Activins initiate cellular signal transduction by first binding to the type II receptors (ACTIVIN RECEPTORS, TYPE II ) which then recruit and phosphorylate the type I receptors (ACTIVIN RECEPTORS, TYPE I ) with subsequent activation of the type I kinase activity.

Activin Receptors, Type I [M0265516]
One of the two types of ACTIVIN RECEPTORS or activin receptor-like kinases (ALK'S). There are several type I activin receptors. The major active ones are ALK-2 (ActR-IA) and ALK-4 (ActR-IB).

Activin Receptors, Type II [M0292107]
One of the two types of ACTIVIN RECEPTORS. They are membrane protein kinases belonging to the family of PROTEIN-SERINE-THREONINE KINASES. The major type II activin receptors are ActR-IIA and ActR-IIB.

Activins [M0150466]
Activins are produced in the pituitary, gonads, and other tissues. By acting locally, they stimulate pituitary FSH secretion and have diverse effects on cell differentiation and embryonic development. Activins are glycoproteins that are hetero- or homodimers of INHIBIN-BETA SUBUNITS.

Actoheavy Meromyosin [M0375374]

Actomyosin [M0000319]
A protein complex of actin and MYOSINS occurring in muscle. It is the essential contractile substance of muscle.

Actomyosin Adenosinetriphosphatase [M0375356]

Actomyosin Subfragments [M0024309]

Acute Myeloid Leukemia 1A Protein [M0215811]

Acute Myeloid Leukemia 1B Protein [M0215812]

Acute Myeloid Leukemia 1C Protein [M0384755]

Acute Myeloid Leukemia 1D Protein [M0215813]

Acute-Phase Glycoproteins [M0000323]

Acute-Phase Proteins [M0000324]
Proteins that are secreted into the blood in increased or decreased quantities by hepatocytes in response to trauma, inflammation, or disease. These proteins can serve as inhibitors or mediators of the inflammatory processes. Certain acute-phase proteins have been used to diagnose and follow the course of diseases or as tumor markers.

Acyl Carrier Protein [M0000330]
Consists of a polypeptide chain and 4'-phosphopantetheine linked to a serine residue by a phosphodiester bond. Acyl groups are bound as thiol esters to the pantothenyl group. Acyl carrier protein is involved in every step of fatty acid synthesis by the cytoplasmic system.

Acyl CoA Desaturases [M0446719]

Acyl CoA Hydrolase [M0015780]

Acyl-Carrier Protein S-Acetyltransferase [M0070591]
A enzyme that catalyzes the transfer of acetyl groups from ACETYL CoA to acyl-carrier protein to form COENZYME A and acetyl-acyl-carrier protein.

Acyl-Carrier Protein S-Malonyltransferase [M0070598]
This enzyme catalyzes the transacylation of malonate from MALONYL CoA to activated holo-ACP, to generate malonyl-(acyl-carrier protein), which is an elongation substrate in FATTY ACIDS biosynthesis. It is an essential enzyme in the biosynthesis of FATTY ACIDS in all BACTERIA.

Acyl-CoA Dehydrogenase [M0070625]
A flavoprotein oxidoreductase that has specificity for medium-chain fatty acids. It forms a complex with ELECTRON TRANSFERRING FLAVOPROTEINS and conveys reducing equivalents to UBIQUINONE.

Acyl-CoA Dehydrogenase, Long-Chain [M0158730]
A flavoprotein oxidoreductase that has specificity for long-chain fatty acids. It forms a complex with ELECTRON-TRANSFERRING FLAVOPROTEINS and conveys reducing equivalents to UBIQUINONE.

Acyl-CoA Dehydrogenases [M0008262]
Enzymes that catalyze the first step in the beta-oxidation of FATTY ACIDS.

Acyl-CoA Oxidase [M0079346]
An enzyme that catalyzes the first and rate-determining steps of peroxisomal beta-oxidation of fatty acids. It acts on COENZYME A derivatives of fatty acids with chain lengths from 8 to 18, using FLAVIN-ADENINE DINUCLEOTIDE as a cofactor.

Acyltransferases [M0000335]
Enzymes from the transferase class that catalyze the transfer of acyl groups from donor to acceptor, forming either esters or amides. (From Enzyme Nomenclature 1992) EC 2.3.

ADAM Proteins [M0481642]
A family of membrane-anchored glycoproteins that contain a disintegrin and metalloprotease domain. They are responsible for the proteolytic cleavage of many transmembrane proteins and the release of their extracellular domain.

Adaptor Protein Complex 1 [M0163799]
A clathrin adaptor protein complex primarily involved in clathrin-related transport at the TRANS-GOLGI NETWORK.

Adaptor Protein Complex 2 [M0333169]
An adaptor protein complex primarily involved in the formation of clathrin-related endocytotic vesicles (ENDOSOMES) at the CELL MEMBRANE.

Adaptor Protein Complex 3 [M0163801]
An adaptor protein complex found primarily on perinuclear compartments.

Adaptor Protein Complex 4 [M0146883]
An adaptor protein complex involved in transport of molecules between the TRANS-GOLGI NETWORK and the endosomal-lysosomal system.

Adaptor Protein Complex alpha Subunits [M0163813]
A family of large adaptin protein subunits of approximately 100 kDa in size. They have been primarily found as components of ADAPTOR PROTEIN COMPLEX 2.

Adaptor Protein Complex beta Subunits [M0175277]
A family of large adaptin protein complex subunits of approximately 90-130 kDa in size.

Adaptor Protein Complex delta Subunits [M0281499]
A family of large adaptin protein subunits of approximately 130-kDa in size. They have been primarily found as components of ADAPTOR PROTEIN COMPLEX 3.

Adaptor Protein Complex gamma Subunits [M0183696]
A family of large adaptin protein subunits of approximately 90 KDa in size. They have been primarily found as components of ADAPTOR PROTEIN COMPLEX 1.

Adaptor Protein Complex mu Subunits [M0404403]
A family of medium adaptin protein subunits of approximately 45 KDa in size. They have been primarily found as components of ADAPTOR PROTEIN COMPLEX 3 and ADAPTOR PROTEIN COMPLEX 4.

Adaptor Protein Complex sigma Subunits [M0404545]
A family of small adaptin protein complex subunits of approximately 19 KDa in size.

Adaptor Protein Complex Subunits [M0404544]
The subunits that make up the large, medium and small chains of adaptor proteins.

Adaptor Protein Complexes, Vesicular Transport [M0404725]
Multisubunit protein complexes of adaptor proteins.

Adaptor Proteins, Signal Transducing [M0462870]
A broad category of carrier proteins that play a role in SIGNAL TRANSDUCTION. They generally contain several modular domains, each of which having its own binding activity, and act by forming complexes with other intracellular-signaling molecules. Signal-transducing adaptor proteins lack enzyme activity, however their activity can be modulated by other signal-transducing enzymes

Adaptor Proteins, Vesicular Transport [M0146907]
A class of proteins involved in the transport of molecules via TRANSPORT VESICLES. They perform functions such as binding to the cell membrane, capturing cargo molecules and promoting the assembly of CLATHRIN. The majority of adaptor proteins exist as multi-subunit complexes, however monomeric varieties have also been found.

Adenine Nucleotide Translocase [M0408259]

Adenine Nucleotide Translocator 1 [M0000349]
A subtype of mitochondrial ADP, ATP translocase found primarily in heart muscle (MYOCARDIUM) and skeletal muscle (MUSCLE, SKELETAL).

Adenine Nucleotide Translocator 2 [M0000350]
A subtype of mitochondrial ADP, ATP translocase found primarily in FIBROBLASTS.

Adenine Nucleotide Translocator 3 [M0000351]
A subtype of mitochondrial ADP, ATP translocase found primarily in the LIVER.

Adenine Phosphoribosyltransferase [M0000353]
An enzyme catalyzing the formation of AMP from adenine and phosphoribosylpyrophosphate. It can act as a salvage enzyme for recycling of adenine into nucleic acids. EC 2.4.2.7.

Adenomatous Polyposis Coli Protein [M0215186]
A negative regulator of beta-catenin signaling which is mutant in ADENOMATOUS POLYPOSIS COLI and GARDNER SYNDROME.

Adenosine Deaminase [M0000379]
An enzyme that catalyzes the hydrolysis of adenosine to inosine with the elimination of ammonia. Since there are wide tissue and species variations in the enzyme, it has been used as a tool in the study of human and animal genetics and in medical diagnosis. EC 3.5.4.4.

Adenosine Kinase [M0000385]
An enzyme that catalyzes the formation of ADP plus AMP from adenosine plus ATP. It can serve as a salvage mechanism for returning adenosine to nucleic acids. EC 2.7.1.20.

Adenosine Triphosphatases [M0000391]
A group of enzymes which catalyze the hydrolysis of ATP. The hydrolysis reaction is usually coupled with another function such as transporting Ca(2+) across a membrane. These enzymes may be dependent on Ca(2+), Mg(2+), anions, H+, or DNA.

Adenosinetriphosphatase [M0493578]

Adenosylhomocysteinase [M0072172]
An enzyme which catalyzes the catabolism of S-ADENOSYLHOMOCYSTEINE to ADENOSINE and HOMOCYSTEINE. It may play a role in regulating the concentration of intracellular adenosylhomocysteine.

Adenosylmethionine Decarboxylase [M0019325]
An enzyme that catalyzes the decarboxylation of S-adenosyl-L-methionine to yield 5'-deoxy-(5'-),3-aminopropyl-(1), methylsulfonium salt. It is one of the enzymes responsible for the synthesis of spermidine from putrescine. EC 4.1.1.50.

Adenovirus 12 Early Region 1B 19K Protein [M0026554]

Adenovirus Core Protein VII [M0022696]

Adenovirus E1 Proteins [M0026549]
The very first viral gene products synthesized after cells are infected with adenovirus. The E1 region of the genome has been divided into two major transcriptional units, E1A and E1B, each expressing proteins of the same name (ADENOVIRUS E1A PROTEINS and ADENOVIRUS E1B PROTEINS).

Adenovirus E19 Proteins [M0026491]

Adenovirus E1A Protein Domain 3 [M0026553]

Adenovirus E1A Proteins [M0026552]
Proteins transcribed from the E1A genome region of ADENOVIRUSES which are involved in positive regulation of transcription of the early genes of host infection.

Adenovirus E1B 19K Protein [M0026556]

Adenovirus E1B Proteins [M0026555]
Proteins transcribed from the E1B region of ADENOVIRUSES which are involved in regulation of the levels of early and late viral gene expression.

Adenovirus E2 Proteins [M0026561]
Proteins transcribed from the E2 region of ADENOVIRUSES. Several of these are required for viral DNA replication.

Adenovirus E29 Protein [M0026492]

Adenovirus E2A 72K Protein [M0026559]

Adenovirus E2A Proteins [M0026557]

Adenovirus E2F Proteins [M0026558]

Adenovirus E3 19K Protein [M0026562]

Adenovirus E3 Proteins [M0026563]
Proteins transcribed from the E3 region of ADENOVIRUSES but not essential for viral replication. The E3 19K protein mediates adenovirus persistence by reducing the expression of class I major histocompatibility complex antigens on the surface of infected cells.

Adenovirus E4 Proteins [M0026564]
Proteins transcribed from the E4 region of ADENOVIRUSES. The E4 19K protein transactivates transcription of the adenovirus E2F protein and complexes with it.

Adenovirus E4F Protein [M0026565]

Adenovirus Early Proteins [M0026490]
Proteins encoded by adenoviruses that are synthesized prior to, and in the absence of, viral DNA replication. The proteins are involved in both positive and negative regulation of expression in viral and cellular genes, and also affect the stability of viral mRNA. Some are also involved in oncogenic transformation.

Adenylate Cyclase [M0000412]
An enzyme of the lyase class that catalyzes the formation of CYCLIC AMP and pyrophosphate from ATP. EC 4.6.1.1.

Adenylate Cyclase Toxin [M0016415]
One of the virulence factors produced by virulent BORDETELLA organisms. It is a bifunctional protein with both ADENYLATE CYCLASE and hemolysin components.

Adenylate Kinase [M0000413]
An enzyme that catalyzes the phosphorylation of AMP to ADP in the presence of ATP or inorganic triphosphate. EC 2.7.4.3.

Adenylosuccinate Lyase [M0000414]
An enzyme that, in the course of purine ribonucleotide biosynthesis, catalyzes the conversion of 5'-phosphoribosyl-4-(N-succinocarboxamide)-5-aminoimidazole to 5'-phosphoribosyl-4-carboxamide-5-aminoimidazole and the conversion of adenylosuccinic acid to AMP. EC 4.3.2.2.

Adenylosuccinate Synthase [M0000415]
A carbon-nitrogen ligase. During purine ribonucleotide biosynthesis, this enzyme catalyzes the synthesis of adenylosuccinate from GTP; IMP; and aspartate with the formation of orthophosphate and GDP. EC 6.3.4.4.

Adhesins, Bacterial [M0028184]
Cell-surface components or appendages of bacteria that facilitate adhesion (BACTERIAL ADHESION) to other cells or to inanimate surfaces. Most fimbriae (FIMBRIAE, BACTERIAL) of gram-negative bacteria function as adhesins, but in many cases it is a minor subunit protein at the tip of the fimbriae that is the actual adhesin. In gram-positive bacteria, a protein or polysaccharide surface layer serves as the specific adhesin. What is sometimes called polymeric adhesin (BIOFILMS) is distinct from protein adhesin.

Adhesins, Escherichia coli [M0028185]
Thin, filamentous protein structures, including proteinaceous capsular antigens (fimbrial antigens), that mediate adhesion of E. coli to surfaces and play a role in pathogenesis. They have a high affinity for various epithelial cells.

Adiponectin [M0260436]
A 30-kDa COMPLEMENT C1Q-related protein, the most abundant gene product secreted by FAT CELLS of the white ADIPOSE TISSUE. Adiponectin modulates several physiological processes, such as metabolism of GLUCOSE and FATTY ACIDS, and immune responses. Decreased plasma adiponectin levels are associated with INSULIN RESISTANCE; TYPE 2 DIABETES MELLITUS; OBESITY; and ATHEROSCLEROSIS.

Adiuretin [M0369335]

Adiuretin SD [M0369334]

ADP Ribose Transferases [M0408809]
Enzymes that transfer the ADP-RIBOSE group of NAD or NADP to proteins or other small molecules. Transfer of ADP-ribose to water (i.e., hydrolysis) is catalyzed by the NADASES. The mono(ADP-ribose)transferases transfer a single ADP-ribose. POLY(ADP-RIBOSE) POLYMERASES transfer multiple units of ADP-ribose to protein targets, building POLY ADENOSINE DIPHOSPHATE RIBOSE in linear or branched chains.

ADP-ribosyl Cyclase [M0160282]
A membrane-bound or cytosolic enzyme that catalyzes the synthesis of CYCLIC ADP-RIBOSE (cADPR) from nicotinamide adenine dinucleotide (NAD). This enzyme generally catalyzes the hydrolysis of cADPR to ADP-RIBOSE, as well, and sometimes the synthesis of cyclic ADP-ribose 2' phosphate (2'-P-cADPR) from NADP.

ADP-Ribosylation Factor 1 [M0328141]
ADP-RIBOSYLATION FACTOR 1 is involved in regulating intracellular transport by modulating the interaction of coat proteins with organelle membranes in the early secretory pathway. It is a component of COAT PROTEIN COMPLEX I. This enzyme was formerly listed as EC 3.6.1.47.

ADP-Ribosylation Factors [M0328150]
MONOMERIC GTP-BINDING PROTEINS that were initially recognized as allosteric activators of the MONO(ADP-RIBOSE) TRANSFERASE of the CHOLERA TOXIN catalytic subunit. They are involved in vesicle trafficking and activation of PHOSPHOLIPASE D. This enzyme was formerly listed as EC 3.6.1.47

Adrenocorticotropic Hormone [M0000499]
An anterior pituitary hormone that stimulates the ADRENAL CORTEX and its production of CORTICOSTEROIDS. ACTH is a 39-amino acid polypeptide of which the N-terminal 24-amino acid segment is identical in all species and contains the adrenocorticotrophic activity. Upon further tissue-specific processing, ACTH can yield ALPHA-MSH and corticotrophin-like intermediate lobe peptide (CLIP).

Adrenodoxin [M0000500]
An iron-sulfur protein which serves as an electron carrier in enzymatic steroid hydroxylation reactions in adrenal cortex mitochondria. The electron transport system which catalyzes this reaction consists of adrenodoxin reductase, NADP, adrenodoxin, and cytochrome P-450.

Adrenomedullin [M0216201]
A 52-amino acid peptide with multi-functions. It was originally isolated from PHEOCHROMOCYTOMA and ADRENAL MEDULLA but is widely distributed throughout the body including lung and kidney tissues. Besides controlling fluid-electrolyte homeostasis, adrenomedullin is a potent vasodilator and can inhibit pituitary ACTH secretion.

Aequorin [M0000509]
A photoprotein isolated from the bioluminescent jellyfish Aequorea. It emits visible light by an intramolecular reaction when a trace amount of calcium ion is added. The light-emitting moiety in the bioluminescence reaction is believed to be 2-amino-3-benzyl-5-(p-hydroxyphenyl)pyrazine (AF-350).

AER-I beta-Lactamase [M0016143]

Aerosporin [M0017215]

Ag-Zn Superoxide Dismutase [M0020833]

AGAMOUS Protein, Arabidopsis [M0221043]
A plant homeotic protein involved in the development of stamens and carpels of Arabidopsis thaliana. It is a DNA-binding protein that contains the MADS-box domain. It is one of the four founder proteins that structurally define the superfamily of MADS DOMAIN PROTEINS.

Agamous-Like Proteins [M0384313]

Agglutinins, Plant [M0412052]

Aggrecans [M0176993]
Large HYALURONAN-containing proteoglycans found in articular cartilage (CARTILAGE, ARTICULAR). They form into aggregates that provide tissues with the capacity to resist high compressive and tensile forces.

Agrin [M0027395]
A protein component of the synaptic basal lamina. It has been shown to induce clustering of acetylcholine receptors on the surface of muscle fibers and other synaptic molecules in both synapse regeneration and development.

Airbron [M0445742]

Ak-Tracin [M0454529]

Alamethicin [M0000618]
A cyclic nonadecapeptide antibiotic that can act as an ionophore and is produced by strains of Trichoderma viride. (From Singleton & Sainsbury, Dictionary of Microbiology and Molecular Biology, 2d ed)

Alanine [M0000619]
A non-essential amino acid that occurs in high levels in its free state in plasma. It is produced from pyruvate by transamination. It is involved in sugar and acid metabolism, increases IMMUNITY, and provides energy for muscle tissue, BRAIN, and the CENTRAL NERVOUS SYSTEM.

Alanine Dehydrogenase [M0072260]
An NAD-dependent enzyme that catalyzes the reversible DEAMINATION of L-ALANINE to PYRUVATE and AMMONIA. The enzyme is needed for growth when ALANINE is the sole CARBON or NITROGEN source. It may also play a role in CELL WALL synthesis because L-ALANINE is an important constituent of the PEPTIDOGLYCAN layer.

Alanine Racemase [M0000622]
A pyridoxal-phosphate protein that reversibly catalyzes the conversion of L-alanine to D-alanine. EC 5.1.1.1.

Alanine Transaminase [M0000620]
An enzyme that catalyzes the conversion of L-alanine and 2-oxoglutarate to pyruvate and L-glutamate. (From Enzyme Nomenclature, 1992) EC 2.6.1.2.

Alanine-tRNA Ligase [M0000623]
An enzyme that activates alanine with its specific transfer RNA. EC 6.1.1.7.

Albumins [M0000629]
Water-soluble proteins found in egg whites, blood, lymph, and other tissues and fluids. They coagulate upon heating.

Alcohol Dehydrogenase [M0000643]
A zinc-containing enzyme which oxidizes primary and secondary alcohols or hemiacetals in the presence of NAD. In alcoholic fermentation, it catalyzes the final step of reducing an aldehyde to an alcohol in the presence of NADH and hydrogen.

Alcohol Dehydrogenase I [M0000644]

Alcohol Dehydrogenase II [M0000645]

Alcohol Oxidoreductases [M0000651]
A subclass of enzymes which includes all dehydrogenases acting on primary and secondary alcohols as well as hemiacetals. They are further classified according to the acceptor which can be NAD+ or NADP+ (subclass 1.1.1), cytochrome (1.1.2), oxygen (1.1.3), quinone (1.1.5), or another acceptor (1.1.99).

Aldehyde Dehydrogenase [M0000673]
An enzyme that oxidizes an aldehyde in the presence of NAD+ and water to an acid and NADH. EC 1.2.1.3. Before 1978, it was classified as EC 1.1.1.70.

Aldehyde Dehydrogenase E1 [M0000674]

Aldehyde Dehydrogenase E2 [M0000675]

Aldehyde Oxidase [M0072305]
An aldehyde oxidoreductase expressed predominantly in the LIVER; LUNGS; and KIDNEY. It catalyzes the oxidation of a variety of organic aldehydes and N-heterocyclic compounds to CARBOXYLIC ACIDS, and also oxidizes QUINOLINE and PYRIDINE derivatives. The enzyme utilizes molybdenum cofactor and FAD as cofactors.

Aldehyde Oxidoreductases [M0000677]
Oxidoreductases that are specific for ALDEHYDES.

Aldehyde Reductase [M0000681]
An enzyme that catalyzes reversibly the oxidation of an aldose to an alditol. It possesses broad specificity for many aldoses. EC 1.1.1.21.

Aldehyde-Ketone Transferases [M0029519]
Enzymes that catalyze the transfer of aldehyde or ketone residues. EC 2.2.

Aldehyde-Lyases [M0000678]
Enzymes that catalyze a reverse aldol condensation. A molecule containing a hydroxyl group and a carbonyl group is cleaved at a C-C bond to produce two smaller molecules (ALDEHYDES or KETONES). EC 4.1.2.

Aldolase A [M0008857]

Aldolase B [M0008858]

Aldolase C [M0008859]

Aldomet [M0013628]

Aldose Reductase Ia [M0000682]

Aldose Reductase Ib [M0000683]

Aldose-Ketose Isomerases [M0029314]
Enzymes that catalyze the interconversion of aldoses and ketoses. EC 5.3.1.

Aldosterone Synthase [M0028872]
A mitochondrial cytochrome P450 enzyme that catalyzes the 18-hydroxylation of steroids in the presence of molecular oxygen and NADPH-specific flavoprotein. This enzyme, encoded by CYP11B2 gene, is important in the conversion of CORTICOSTERONE to 18-hydroxycorticosterone and the subsequent conversion to ALDOSTERONE.

Algal Peptides [M0030074]

Algal Proteins [M0030075]
Proteins found in any species of algae.

Alkaline DNase [M0006013]

Alkaline Phosphatase [M0000712]
An enzyme that catalyzes the conversion of an orthophosphoric monoester and water to an alcohol and orthophosphate. EC 3.1.3.1.

Alkaline Ribonuclease [M0019069]

Alkane 1-Monooxygenase [M0076535]
A P450 oxidoreductase that catalyzes the hydroxylation of the terminal carbon of linear hydrocarbons such as OCTANE and FATTY ACIDS in the omega position. The enzyme may also play a role in the oxidation of a variety of structurally unrelated compounds such as XENOBIOTICS, and STEROIDS.

Alkeran [M0013332]

Alkyl and Aryl Transferases [M0029524]
A somewhat heterogeneous class of enzymes that catalyze the transfer of alkyl or related groups (excluding methyl groups). EC 2.5.

Alkyltransferases [M0029522]

Allerglobuline [M0373035]

Alloisoleucine [M0011765]

Allophanate Hydrolase [M0000744]
An enzyme that catalyzes the hydrolysis of allophanic acid to two molecules of ammonia plus two molecules of "active carbon dioxide". EC 3.5.1.54.

Allylglycine [M0000753]
An inhibitor of glutamate decarboxylase and an antagonist of GAMMA-AMINOBUTYRIC ACID. It is used to induce convulsions in experimental animals.

alpha 1-Acid Glycoprotein (Acute Phase) [M0015444]

alpha 1-Acute Phase Globulin [M0000767]

alpha 1-Acute Phase Protein [M0000766]

alpha 1-Antichymotrypsin [M0000778]
Glycoprotein found in alpha(1)-globulin region in human serum. It inhibits chymotrypsin-like proteinases in vivo and has cytotoxic killer-cell activity in vitro. The protein also has a role as an acute-phase protein and is active in the control of immunologic and inflammatory processes, and as a tumor marker. It is a member of the serpin superfamily.

alpha 1-Antitrypsin [M0000780]
Plasma glycoprotein member of the serpin superfamily which inhibits TRYPSIN; NEUTROPHIL ELASTASE; and other PROTEOLYTIC ENZYMES. Commonly referred to as alpha 1-proteinase inhibitor (A1PI), it exists in over 30 different biochemical variant forms known collectively as the Pi (protease inhibitor) system. Hereditary A1PI deficiency is associated with PULMONARY EMPHYSEMA.

alpha 1-Macroglobulin [M0000768]

alpha 1-Proteinase Inhibitor F [M0000781]

alpha 1-Proteinase Inhibitor S [M0000782]

alpha 2-Acute Phase Globulins [M0000769]

alpha 2-Glucoproteins [M0000770]

alpha Catenin [M0188648]
A catenin that binds F-ACTIN and links the CYTOSKELETON with BETA CATENIN and GAMMA CATENIN.

alpha Karyopherins [M0240469]
Nucleocytoplasmic transport molecules that bind to the NUCLEAR LOCALIZATION SIGNALS of cytoplasmic molecules destined to be imported into the CELL NUCLEUS. Once attached to their cargo they bind to BETA KARYOPHERINS and are transported through the NUCLEAR PORE COMPLEX. Inside the CELL NUCLEUS alpha karyopherins dissociate from beta karypherins and their cargo. They then form a complex with CELLULAR APOPTOSIS SUSCEPTIBILITY PROTEIN and RAN GTP-BINDING PROTEIN which is exported to the CYTOPLASM.

Alpha(1) Antiplasmin [M0001392]

alpha(S1)-Casein [M0003596]

alpha(S1)-Casein A [M0003597]

alpha(S1)-Casein B [M0003598]

alpha(S1)-Casein C [M0003599]

alpha(S2)-Casein [M0003586]

alpha, alpha-Enolase [M0016706]

alpha-1 Globin [M0009280]

alpha-1 Lipoprotein [M0012582]

alpha-2 Chimerin [M0331682]

alpha-Actin [M0000297]

alpha-Actinin [M0000278]

Alpha-Amanitin [M0000844]

Alpha-Amanitine [M0000845]

alpha-Amylase [M0000783]
An enzyme that catalyzes the endohydrolysis of 1,4-alpha-glycosidic linkages in starch, glycogen, and related polysaccharides and oligosaccharides containing 3 or more 1,4-alpha-linked D-glucose units. EC 3.2.1.1.

alpha-Amylase 2 [M0000785]

Alpha-Amylase Bayer [M0477123]

alpha-Atrial Natriuretic Peptide [M0014513]
A potent circulating form of ANP that is a 28-amino acid peptide. It derives from the (99-126) amino acids of prohormone gamma-ANP, also known as ANP (1-126).

alpha-Caseins [M0003587]

alpha-Catulin [M0479530]

alpha-Caveolin [M0209020]

alpha-CGRP [M0024124]

Alpha-Chymotrypsin Choay [M0478344]

Alpha-Chymotrypsinogen [M0004467]

alpha-Collagen [M0004774]

alpha-Conotoxins [M0333357]

alpha-Crystallin A Chain [M0005387]
One of the subunits of alpha-crystallins. Unlike ALPHA-CRYSTALLIN B CHAIN the expression of ALPHA-CRYSTALLIN A CHAIN is limited primarily to the lens (LENS, CRYSTALLINE).

alpha-Crystallin B Chain [M0005401]
One of the alpha crystallin subunits. In addition to being expressed in the lens (LENS, CRYSTALLINE), alpha-crystallin B chain has been found in a variety of tissues such as HEART; BRAIN; MUSCLE; and KIDNEY. Accumulation of the protein in the brain is associated with NEURODEGENERATIVE DISEASES such as CREUTZFELDT-JAKOB SYNDROME and ALEXANDER DISEASE.

alpha-Crystallins [M0005389]
A subclass of crystallins that provides the majority of refractive power and translucency to the lens (LENS, CRYSTALLINE) in VERTEBRATES. Alpha-crystallins also act as molecular chaperones that bind to denatured proteins, keep them in solution and thereby maintain the translucency of the lens. The proteins exist as large oligomers that are formed from ALPHA-CRYSTALLIN A CHAIN and ALPHA-CRYSTALLIN B CHAIN subunits.

alpha-Defensins [M0360491]
DEFENSINS found in azurophilic granules of neutrophils and in the secretory granules of intestinal PANETH CELLS.

alpha-Dystroglycan [M0454540]

alpha-Elastin [M0007151]

alpha-Endorphin [M0028178]
An endogenous opioid peptide derived from BETA-LIPOTROPIN of the pro-opiomelanocortin (POMC) system. It is the 16-amino acid sequence of the N-terminal of BETA-ENDORPHIN and differs from GAMMA-ENDORPHIN by one amino acid (beta-endorphin 1-17).

alpha-Fetoproteins [M0000763]
The first alpha-globulins to appear in mammalian sera during development of the embryo and the dominant serum proteins in early embryonic life. They reappear in the adult serum during certain pathologic states, primarily hepatocellular carcinoma. They may also be elevated in the amniotic fluid and maternal serum during pregnancy in ANENCEPHALY.

alpha-Galactosidase [M0000793]
An enzyme that catalyzes the hydrolysis of terminal, non-reducing alpha-D-galactose residues in alpha-galactosides including galactose oligosaccharides, galactomannans, and galactolipids.

alpha-Gliadin [M0009262]

alpha-Globin [M0009281]

Alpha-Globulins [M0000765]
Serum proteins that have the most rapid migration during ELECTROPHORESIS. This subgroup of globulins is divided into faster and slower alpha(1)- and alpha(2)-globulins.

alpha-Glucosidases [M0000794]
Enzymes that catalyze the exohydrolysis of 1,4-alpha-glucosidic linkages with release of alpha-glucose. Deficiency of alpha-1,4-glucosidase may cause GLYCOGEN STORAGE DISEASE TYPE II.

alpha-Haemocyanin [M0010099]

alpha-Isoactin [M0000298]

alpha-Kallikrein [M0011894]

alpha-Keratin [M0494274]

alpha-L-Fucosidase [M0008874]
An enzyme that catalyzes the hydrolysis of an alpha L-fucoside to yield an alcohol and L-fucose. Deficiency of this enzyme can cause FUCOSIDOSIS. EC 3.2.1.51.

alpha-Lactalbumin [M0012138]

alpha-Lactalbumin A [M0012139]

alpha-Lactalbumin B [M0012140]

alpha-Lactalbumin C [M0012141]

alpha-Macrofetoprotein [M0000773]

alpha-Macroglobulins [M0000771]
Glycoproteins with a molecular weight of approximately 620,000 to 680,000. Precipitation by electrophoresis is in the alpha region. They include alpha 1-macroglobulins and alpha 2-macroglobulins. These proteins exhibit trypsin-, chymotrypsin-, thrombin-, and plasmin-binding activity and function as hormonal transporters.

alpha-Mannosidase [M0085930]
An enzyme that catalyzes the HYDROLYSIS of terminal, non-reducing alpha-D-mannose residues in alpha-D-mannosides. The enzyme plays a role in the processing of newly formed N-glycans and in degradation of mature GLYCOPROTEINS. There are multiple isoforms of alpha-mannosidase, each having its own specific cellular location and pH optimum. Defects in the lysosomal form of the enzyme results in a buildup of mannoside intermediate metabolites and the disease ALPHA-MANNOSIDOSIS.

alpha-Methyltyrosine [M0029394]
An inhibitor of the enzyme TYROSINE 3-MONOOXYGENASE, and consequently of the synthesis of catecholamines. It is used to control the symptoms of excessive sympathetic stimulation in patients with PHEOCHROMOCYTOMA. (Martindale, The Extra Pharmacopoeia, 30th ed)

alpha-Methyltyrosine Hydrochloride [M0329126]

alpha-MSH [M0000797]
A 13-amino acid peptide derived from proteolytic cleavage of ADRENOCORTICOTROPIC HORMONE, the N-terminal segment of ACTH. ACTH (1-13) is amidated at the C-terminal to form ACTH (1-13)NH2 which in turn is acetylated to form alpha-MSH in the secretory granules. Alpha-MSH stimulates the synthesis and distribution of MELANIN in MELANOCYTES in mammals and MELANOPHORES in lower vertebrates.

alpha-N-Acetylgalactosaminidase [M0063960]
A hexosaminidase with specificity for terminal non-reducing N-acetyl-D-galactosamine residues in N-acetyl-alpha-D-galactosaminides.

alpha-P85 Subunit, PI-3K [M0029505]

Alpha-Peroxidase [M0010545]

alpha-Sarcoglycan [M0223527]

alpha-Secretase [M0205212]

alpha-SNAP [M0202544]

alpha-Spectrin [M0020226]

Alpha-Stathmin [M0166753]

alpha-Synuclein [M0159750]
A synuclein that is a major component of LEWY BODIES that plays a role in neurodegeneration and neuroprotection.

alpha-Thrombin [M0021420]

alpha-Toxin [M0016674]

alpha-Transducin [M0023546]

alpha-Tropomyosin [M0022041]

alpha-Tryptases [M0496632]

alpha-Tubulin [M0022139]

alpha-Vinculin [M0025313]

alpha2-Very-Low-Density Lipoproteins [M0012593]

Alphacutan�e [M0478343]

Alphaglobin [M0025532]

Altracin [M0454536]

Aluminum L-Glutamate [M0009379]

Alveolex [M0445743]

AM424 [M0097294]

Amanitins [M0000846]
Cyclic peptides extracted from carpophores of various mushroom species. They are potent inhibitors of RNA polymerases in most eukaryotic species, blocking the production of mRNA and protein synthesis. These peptides are important in the study of transcription. Alpha-amanitin is the main toxin from the species Amanitia phalloides, poisonous if ingested by humans or animals.

Amelogenin [M0046530]
A major dental enamel-forming protein found in mammals. In humans the protein is encoded by GENES found on both the X CHROMOSOME and the Y CHROMOSOME.

Amicar [M0351469]

Amide Synthases [M0029294]
Enzymes that catalyze the joining of either ammonia or an amide with another molecule, in which the linkage is in the form of a carbon-nitrogen bond. EC 6.3.1.

Amidine-Lyases [M0029322]
These enzymes catalyze the elimination of ammonia from amidines with the formation of a double bond. EC 4.3.2.

Amidinotransferases [M0000899]
Enzymes of a subclass of TRANSFERASES that catalyze the transfer of an amidino group from donor to acceptor. EC 2.1.4.

Amidohydrolases [M0000901]

Amidophosphoribosyltransferase [M0000902]
An enzyme, involved in the early steps of purine nucleotide biosynthesis, that catalyzes the formation of 5-phosphoribosylamine from glutamine and phosphoribosylpyrophosphate. EC 2.4.2.14.

Amine Oxidase (Copper-Containing) [M0010388]
A group of enzymes including those oxidizing primary monoamines, diamines, and histamine. They are copper proteins, and, as their action depends on a carbonyl group, they are sensitive to inhibition by semicarbazide. EC 1.4.3.6.

Amino Acid Chloromethyl Ketones [M0000915]
Inhibitors of SERINE ENDOPEPTIDASES and sulfhydryl group-containing enzymes. They act as alkylating agents and are known to interfere in the translation process.

Amino Acid Isomerases [M0000916]
Enzymes that catalyze either the racemization or epimerization of chiral centers within amino acids or derivatives. EC 5.1.1.

Amino Acid Naphthylamidases [M0000919]

Amino Acid Oxidoreductases [M0000920]
A class of enzymes that catalyze oxidation-reduction reactions of amino acids.

Amino Acid Permeases [M0099794]
Amino acid transporters found in yeasts, plants and lower organisms. However, the distinction between the terms permease and transporter has not been consistently maintained in the literature.

Amino Acid Racemases [M0000917]

Amino Acid Transport System A [M0379253]
A sodium-dependent neutral amino acid transporter that accounts for most of the sodium-dependent neutral amino acid uptake by mammalian cells. The preferred substrates for this transporter system include ALANINE; SERINE; and GLUTAMINE.

Amino Acid Transport System ASC [M0379390]
A ubiquitous sodium-dependent neutral amino acid transporter. The preferred substrates for this transporter system include ALANINE; SERINE; and CYSTEINE.

Amino Acid Transport System L [M0151518]
A sodium-independent neutral amino acid transporter system with specificity for large amino acids. One of the functions of the transporter system is to supply large neutral amino acids to the brain.

Amino Acid Transport System X-AG [M0379930]
A family of POTASSIUM and SODIUM-dependent acidic amino acid transporters that demonstrate a high affinity for GLUTAMIC ACID and ASPARTIC ACID. Several variants of this system are found in neuronal tissue.

Amino Acid Transport System y+ [M0379670]
A sodium-independent, basic amino acid transport system with a high-affinity for LYSINE; ARGININE; and ORNITHINE.

Amino Acid Transport System y+L [M0379762]
A leucine-sensitive amino acid transport system with high affinity for basic amino acids( AMINO ACIDS, BASIC).

Amino Acid Transport Systems [M0151519]
Cellular proteins and protein complexes that transport amino acids across biological membranes.

Amino Acid Transport Systems, Acidic [M0379251]
Amino acid transporter systems capable of transporting acidic amino acids (AMINO ACIDS, ACIDIC).

Amino Acid Transport Systems, Basic [M0379252]
Amino acid transporter systems capable of transporting basic amino acids (AMINO ACIDS, BASIC).

Amino Acid Transport Systems, Neutral [M0379250]
Amino acid transporter systems capable of transporting neutral amino acids (AMINO ACIDS, NEUTRAL).

Amino Acids [M0000922]
Organic compounds that generally contain an amino (-NH2) and a carboxyl (-COOH) group. Twenty alpha-amino acids are the subunits which are polymerized to form proteins.

Amino Acids, Acidic [M0370116]
Amino acids with side chains that are negatively charged at physiological pH.

Amino Acids, Aromatic [M0370111]
Amino acids containing an aromatic side chain.

Amino Acids, Basic [M0370134]
Amino acids with side chains that are positively charged at physiological pH.

Amino Acids, Branched-Chain [M0000923]
Amino acids which have a branched carbon chain.

Amino Acids, Cyclic [M0000924]
A class of amino acids characterized by a closed ring structure.

Amino Acids, Diamino [M0000925]

Amino Acids, Dicarboxylic [M0000926]

Amino Acids, Essential [M0000927]
Amino acids that are not synthesized by the human body in amounts sufficient to carry out physiological functions. They are obtained from dietary foodstuffs.

Amino Acids, Neutral [M0354106]
Amino acids with uncharged R groups or side chains.

Amino Acids, Peptides, and Proteins [M0000928]
Amino acids and chains of amino acids connected by peptide linkages.

Amino Acids, Sulfur [M0000929]

Amino Acyl-tRNA Synthetases [M0000930]
A subclass of enzymes that aminoacylate AMINO ACID-SPECIFIC TRANSFER RNA with their corresponding AMINO ACIDS.

Amino-Acid N-Acetyltransferase [M0070469]
A mitochondrial matrix enzyme that catalyzes the synthesis of L-GLUTAMATE to N-acetyl-L-glutamate in the presence of ACETYL-COA.

Aminoacyltransferases [M0029520]
Enzymes that catalyze the transfer of an aminoacyl group from donor to acceptor resulting in the formation of an ester or amide linkage. EC 2.3.2.

Aminobutyric Acid [M0000941]

Aminobutyric Acids [M0000940]
Aliphatic four carbon acids substituted in any position(s) with amino group(s). They are found in most living things. The best known is GAMMA-AMINOBUTYRIC ACID.

Aminocaproic Acids [M0000942]
A group of compounds that are derivatives of aminohexanoic acids.

Aminoglycoside 3'-Phosphotransferases (I and II) [M0029495]

Aminoglycoside Phosphotransferase Type III [M0029498]

Aminohydrolases [M0000948]

Aminoisobutyric Acids [M0000950]
A group of compounds that are derivatives of the amino acid 2-amino-2-methylpropanoic acid.

Aminolevulinic Acid [M0000951]
A compound produced from succinyl-CoA and GLYCINE as an intermediate in heme synthesis. It is used as a PHOTOCHEMOTHERAPY for actinic KERATOSIS.

Aminolevulinic Acid Hydrochloride [M0477089]

Aminomethyltransferase [M0074977]
A one-carbon group transferase that transfers lipoamide-linked methylamine groups to tetrahydrofolate (TETRAHYDROFOLATES) to form methylenetetrahydrofolate and AMMONIA. It is one of four components of the glycine decarboxylase complex.

Aminomuconate-Semialdehyde Dehydrogenase [M0285718]
An NAD+ dependent enzyme that catalyzes the oxidation of 2-aminomuconate 6-semialdehyde to 2-aminomuconate.

Aminooligopeptidase [M0114960]
Intestinal aminopeptidase N.

Aminopeptidases [M0000957]
A subclass of EXOPEPTIDASES that act on the free N terminus end of a polypeptide liberating a single amino acid residue. EC 3.4.11.

Aminophospholipid Transfer Proteins [M0069070]

Aminopyrine N-Demethylase [M0000966]

Ammonia-Lyases [M0000982]
Enzymes that catalyze the formation of a carbon-carbon double bond by the elimination of AMMONIA. EC 4.3.1.

AMP Deaminase [M0001011]
An enzyme that catalyzes the deamination of AMP to IMP. EC 3.5.4.6.

Amphibian Proteins [M0385419]
Proteins obtained from species in the class of AMPHIBIA.

Amylases [M0001046]
A group of amylolytic enzymes that cleave starch, glycogen, and related alpha-1,4-glucans. (Stedman, 25th ed) EC 3.2.1.-.

Amyloid [M0001047]
A type of extracellularly deposited substance composed of an amyloid protein and additional components including HEPARAN SULFATE PROTEOGLYCAN; LAMININ; COLLAGEN TYPE IV; SERUM AMYLOID P-COMPONENT; and APOLIPOPROTEINS E which together form characteristic amyloid fibrils. The core of amyloid fibrils is formed by the stacking of overlapping beta-pleated sheet domains of the amyloid protein. There are many different amyloid proteins that have been found forming the core of the fibrils in vivo. However, amyloid can be formed from any protein that exposes beta-pleated strand conformations during unfolding or refolding. A common characteristic of amyloid is the ability to bind such dyes as CONGO RED and thioflavine.

Amyloid A Protein [M0001051]
The non-circulating form of serum amyloid A protein. It is found deposited in a variety of tissues during AMYLOIDOSIS.

Amyloid beta-Protein [M0024786]
A 4-kDa protein, 39-43 amino acids long, expressed by a gene located on chromosome 21. It is the major protein subunit of the vascular and plaque amyloid filaments in individuals with Alzheimer's disease and in aged individuals with trisomy 21 (DOWN SYNDROME). The protein is found predominantly in the nervous system, but there have been reports of its presence in non-neural tissue.

Amyloid beta-Protein Precursor [M0025265]
A precursor to the AMYLOID-BETA PROTEIN (beta/A4). Alterations in the expression of the amyloid beta-protein precursor (ABPP) gene, located on chromosome 21, plays a role in the development of the neuropathology common to both ALZHEIMER DISEASE and DOWN SYNDROME. ABPP is associated with the extensive extracellular matrix secreted by neuronal cells. Upon cleavage, this precursor produces three proteins of varying amino acid lengths: 695, 751, and 770. The beta/A4 (695 amino acids) or beta-amyloid protein is the principal component of the extracellular amyloid in senile plaques found in ALZHEIMER DISEASE; DOWN SYNDROME and, to a limited extent, in normal aging.

Amyloid Fibrils [M0455694]

Amyloid Precursor Protein Secretases [M0205216]
Endopeptidases that are specific for AMYLOID PROTEIN PRECURSOR. Three secretase subtypes referred to as alpha, beta, and gamma have been identified based upon the region of amyloid protein precursor they cleave.

Amyloid Proteins [M0455693]
Proteins that form the core of amyloid fibrils. For example, the core of amyloid A is formed from amyloid A protein, also known as serum amyloid A protein or SAA protein.

Amylopectin Branching Enzyme [M0023174]

Anakinra [M0494869]
A synthetic form of native human IL-1Ra that has an additional methionine residue at its amino terminus.

Ananase [M0002935]

Anaphylatoxin [M0001075]

Anaphylatoxins [M0001074]
Serum peptides derived from certain cleaved COMPLEMENT PROTEINS during COMPLEMENT ACTIVATION. They induce smooth MUSCLE CONTRACTION; mast cell HISTAMINE RELEASE; PLATELET AGGREGATION; and act as mediators of the local inflammatory process. The order of anaphylatoxin activity from the strongest to the weakest is C5a, C3a, C4a, and C5a des-arginine.

Ancrod [M0001092]
An enzyme fraction from the venom of the Malayan pit viper, Agkistrodon rhodostoma. It catalyzes the hydrolysis of a number of amino acid esters and a limited proteolysis of fibrinogen. It is used clinically to produce controlled defibrination in patients requiring anticoagulant therapy. EC 3.4.21.-.

Androgen-Binding Protein [M0001104]
Carrier proteins produced in the Sertoli cells of the testis, secreted into the seminiferous tubules, and transported via the efferent ducts to the epididymis. They participate in the transport of androgens. Androgen-binding protein has the same amino acid sequence as SEX HORMONE-BINDING GLOBULIN. They differ by their sites of synthesis and post-translational oligosaccharide modifications.

Androgen-Dependent Epididymal Secretory Proteins [M0387590]
Epididymal secretory proteins that are stimulated by androgen.

Androsterone UDP-Glucuronosyltransferase [M0022217]

Angiogenesis Factor Inhibitors [M0095952]

Angiogenic Peptides [M0441467]

Angiogenic Proteins [M0441466]
Intercellular signaling peptides and proteins that regulate the proliferation of new blood vessels under normal physiological conditions (ANGIOGENESIS, PHYSIOLOGICAL). Aberrant expression of angiogenic proteins during disease states such as tumorigenesis can also result in PATHOLOGICAL ANGIOGENESIS.

Angiopoietin-1 [M0270236]
The first to be discovered member of the angiopoietin family. It may play a role in increasing the sprouting and branching of BLOOD VESSELS. Angiopoietin-1 specifically binds to and stimulates the TIE-2 RECEPTOR. Several isoforms of angiopoietin-1 occur due to ALTERNATIVE SPLICING of its mRNA.

Angiopoietin-2 [M0277968]
An angiopoietin that is closely related to ANGIOPOIETIN-1. It binds to the TIE-2 RECEPTOR without receptor stimulation and antagonizes the effect of ANGIOPOIETIN-1. However its antagonistic effect may be limited to cell receptors that occur within the vasculature. Angiopoietin-2 may therefore play a role in down-regulation of BLOOD VESSEL branching and sprouting.

Angiopoietins [M0441729]
A family of structurally-related angiogenic proteins of approximately 70 kDa in size. They have high specificity for members of the TIE RECEPTOR FAMILY.

Angiostatic Peptides [M0442527]

Angiostatic Proteins [M0442526]
Proteins that specifically inhibit the growth of new blood vessels (ANGIOGENESIS, PHYSIOLOGIC).

Angiostatins [M0238172]
Circulating 38-kDa proteins that are internal peptide fragments of PLASMINOGEN. The name derives from the fact that they are potent ANGIOGENESIS INHIBITORS. Angiostatins contain four KRINGLE DOMAINS which are associated with their potent angiostatic activity.

Angiotensin Amide [M0001200]
The octapeptide amide of bovine angiotensin II used to increase blood pressure by vasoconstriction.

Angiotensin I [M0001201]
The decapeptide precursor of ANGIOTENSIN II, generated by the action of renin on angiotensinogen. It has limited pharmacologic activity.

Angiotensin II [M0001202]
The active form of angiotensin. An octapeptide found in blood, it is synthesized from ANGIOTENSIN I and quickly destroyed. Angiotensin II causes profound vasoconstriction with a resulting increase in blood pressure. It differs among species by the amino acid in position 5. The human form has ISOLEUCINE in this position. The clinically and experimentally used bovine form has VALINE in position 5. Medically useful antagonism is obtained with ACE INHIBITORS or with ANGIOTENSIN II TYPE 1 RECEPTOR BLOCKERS.

Angiotensin II, Ile(5)- [M0055996]

Angiotensin II, Val(5)- [M0001205]

Angiotensin III [M0001206]
A heptapeptide formed by the enzymatic hydrolysis of ANGIOTENSIN II. It has greater activity than angiotensin II for stimulating aldosterone synthesis and in the release of prostaglandins but only 20% of the pressor activity.

Angiotensinogen [M0001208]
An alpha-globulin of which a fragment of 14 amino acids is converted by renin to angiotensin I, the inactive precursor of angiotensin II. It is a member of the serpin superfamily.

Angiotensins [M0001210]
Oligopeptides ranging in size from angiotensin precursors with 14 amino acids to the active vasoconstrictor angiotensin II with 8 amino acids, or their analogs or derivatives. The amino acid content varies with the species and changes in that content produce antagonistic or inactive compounds.

Aniline Hydroxylase [M0001216]
A drug-metabolizing, cytochrome P-450 enzyme which catalyzes the hydroxylation of aniline to hydroxyaniline in the presence of reduced flavoprotein and molecular oxygen. EC 1.14.14.-.

Animal Lectins [M0412209]

Anion Exchange Protein 1, Erythrocyte [M0002166]
A ubiquitous membrane transport protein found in the plasma membrane of diverse cell types and tissues, and in nuclear, mitochondrial, and Golgi membranes. It is the major integral transmembrane protein of the erythrocyte plasma membrane, comprising 25% of the total membrane protein. It exists as a dimer and performs the important function of allowing the efficient transport of bicarbonate across erythrocyte cell membranes in exchange for chloride ion.

Anion Exchange Proteins [M0027076]

Anion Pumps [M0025339]

Anion Transport Proteins [M0076807]
Membrane proteins whose primary function is to facilitate the transport of negatively charged molecules (anions) across a biological membrane.

Anion Transport Proteins (Hepatocyte Plasma Membrane) [M0076797]

Anistreplase [M0024829]
An acylated inactive complex of streptokinase and human lysine-plasminogen. After injection, the acyl group is slowly hydrolyzed, producing an activator that converts plasminogen to plasmin, thereby initiating fibrinolysis. Its half-life is about 90 minutes compared to 5 minutes for TPA; (TISSUE PLASMINOGEN ACTIVATOR); 16 minutes for URINARY PLASMINOGEN ACTIVATOR and 23 minutes for STREPTOKINASE. If treatment is initiated within 3 hours of onset of symptoms for acute myocardial infarction, the drug preserves myocardial tissue and left ventricular function and increases coronary artery patency. Bleeding complications are similar to other thrombolytic agents.

Ankyrins [M0026529]
A family of membrane-associated proteins responsible for the attachment of the cytoskeleton. Erythrocyte-related isoforms of ankyrin attach the SPECTRIN cytoskeleton to a transmembrane protein (ANION EXCHANGE PROTEIN 1, ERYTHROCYTE) in the erythrocyte plasma membrane. Brain-related isoforms of ankyrin also exist.

Annexin A1 [M0026275]
Protein of the annexin family exhibiting lipid interaction and steroid-inducibility.

Annexin A11 [M0026272]

Annexin A2 [M0026276]
A member of the annexin family that is a substrate for a tyrosine kinase, ONCOGENE PROTEIN PP60(V-SRC). Annexin A2 occurs as a 36-KDa monomer and in a 90-KDa complex containing two subunits of annexin A2 and two subunits of S100 FAMILY PROTEIN P11. The monomeric form of annexin A2 was formerly referred to as calpactin I heavy chain.

Annexin A2, P90 Complex [M0459687]
A 90-KD complex containing two subunits of Annexin A2 and two subunits of S100 FAMILY PROTEIN P11.

Annexin A3 [M0026298]
A protein of the annexin family that catalyzes the conversion of 1-D-inositol 1,2-cyclic phosphate and water to 1-D-myo-inositol 1-phosphate.

Annexin A4 [M0026293]
Protein of the annexin family originally isolated from the electric organ of the electric ray Torpedo marmorata. It has been found in a wide range of mammalian tissue where it is localized to the apical membrane of polarized EPITHELIAL CELLS.

Annexin A5 [M0026274]
A protein of the annexin family isolated from human PLACENTA and other tissues. It inhibits cytosolic PHOSPHOLIPASE A2, and displays anticoagulant activity.

Annexin A6 [M0026297]
Protein of the annexin family with a probable role in exocytotic and endocytotic membrane events.

Annexin A7 [M0026283]
An annexin family member that plays a role in MEMBRANE FUSION and signaling via VOLTAGE-DEPENDENT CALCIUM CHANNELS.

Annexin A8 [M0026273]

Annexin B10 [M0026271]

Annexin B9 [M0026270]

Annexins [M0026268]
Family of calcium- and phospholipid-binding proteins which are structurally related and exhibit immunological cross-reactivity. Each member contains four homologous 70-kDa repeats. The annexins are differentially distributed in vertebrate tissues (and lower eukaryotes) and appear to be involved in MEMBRANE FUSION and SIGNAL TRANSDUCTION.

Anserine [M0001286]

Antenna Polypeptide, Bacterial [M0200877]

Antennapedia Homeodomain Protein [M0178796]
Antennapedia homeodomain protein is a homeobox protein involved in limb patterning in ARTHROPODS. Mutations in the gene for the antennapedia homeodomain protein are associated with the conversion of antenna to leg or leg to antenna DROSOPHILA.

Anthranilate Phosphoribosyltransferase [M0001310]
An enzyme that catalyzes the formation of N-5'-phosphoribosylanthranilic acid from anthranilate and phosphoribosylpyrophosphate, the first step in tryptophan synthesis in E. coli. It exists in a complex with ANTHRANILATE SYNTHASE in bacteria. EC 2.4.2.18.

Anthranilate Synthase [M0001311]
An enzyme that catalyzes the formation of anthranilate (o-aminobenzoate) and pyruvic acid from chorismate and glutamine. Anthranilate is the biosynthetic precursor of tryptophan and numerous secondary metabolites, including inducible plant defense compounds. EC 4.1.3.27.

Anthranilate Synthase Component I [M0001312]

Anthrogon [M0329002]

Antibiotic 899 [M0372896]

Antibodies, Anti-DNA [M0001489]

Antibodies, Anti-Idiotypic [M0001324]
Antibodies which react with the individual structural determinants (idiotopes) on the variable region of other antibodies.

Antibodies, Anticardiolipin [M0026053]
Antiphospholipid antibodies found in association with systemic lupus erythematosus (LUPUS ERYTHEMATOSUS, SYSTEMIC;), ANTIPHOSPHOLIPID SYNDROME; and in a variety of other diseases as well as in healthy individuals. The antibodies are detected by solid-phase IMMUNOASSAY employing the purified phospholipid antigen CARDIOLIPIN.

Antibodies, Antinuclear [M0001488]
Autoantibodies directed against various nuclear antigens including DNA, RNA, histones, acidic nuclear proteins, or complexes of these molecular elements. Antinuclear antibodies are found in systemic autoimmune diseases including systemic lupus erythematosus, Sjogren's syndrome, scleroderma, polymyositis, and mixed connective tissue disease.

Antibodies, Antiphospholipid [M0026052]
Autoantibodies directed against phospholipids. These antibodies are characteristically found in patients with systemic lupus erythematosus (LUPUS ERYTHEMATOSUS, SYSTEMIC;), ANTIPHOSPHOLIPID SYNDROME; related autoimmune diseases, some non-autoimmune diseases, and also in healthy individuals.

Antibodies, Bacterial [M0001353]
Immunoglobulins induced by substances elaborated by BACTERIA that have an antigenic activity.

Antibodies, Bispecific [M0027219]
Antibodies, often monoclonal, in which the two antigen-binding sites are specific for separate ANTIGENIC DETERMINANTS. They are artificial antibodies produced by chemical crosslinking, fusion of HYBRIDOMA cells, or by molecular genetic techniques. They function as the main mediators of targeted cellular cytotoxicity and have been shown to be efficient in the targeting of drugs, toxins, radiolabeled haptens, and effector cells to diseased tissue, primarily tumors.

Antibodies, Catalytic [M0026051]
Antibodies that can catalyze a wide variety of chemical reactions. They are characterized by high substrate specificity and share many mechanistic features with enzymes.

Antibodies, Fungal [M0001354]
Immunoglobulins induced by substances elaborated by FUNGI that have an antigenic activity.

Antibodies, Heterophile [M0001356]
Antibodies elicited in a different species from which the antigen originated. These antibodies are directed against a wide variety of interspecies-specific antigens, the best known of which are Forssman, Hanganutziu-Deicher (H-D), and Paul-Bunnell (P-B). Incidence of antibodies to these antigens--i.e., the phenomenon of heterophile antibody response--is useful in the serodiagnosis, pathogenesis, and prognosis of infection and latent infectious states as well as in cancer classification.

Antibodies, Phospho-Specific [M0447309]
Antibodies directed against immunogen-coupled phosphorylated PEPTIDES corresponding to amino acids surrounding the PHOSPHORYLATION site. They are used to study proteins involved in SIGNAL TRANSDUCTION pathways. (From Methods Mol Biol 2000; 99:177-89)

Antibodies, Viral [M0001361]
Immunoglobulins produced as a response to VIRAL ANTIGENS; includes all classes of immunoglobulins elicited by all viral components.

Antibody Fragments [M0481967]

Antifreeze Glycoproteins [M0068036]

Antifreeze Proteins [M0068035]
Proteins that bind to ice and modify the growth of ice crystals. They perform a cryoprotective role in a variety of organisms.

Antifreeze Proteins, Type I [M0352463]
A subclass of ANTIFREEZE PROTEINS that are 3-5 kDa in size and contain a single alanine-rich amphipathic alpha-helix.

Antifreeze Proteins, Type II [M0352464]
A subclass of ANTIFREEZE PROTEINS that have a cystine-rich globular structure of approximately 14 kD.

Antifreeze Proteins, Type III [M0352481]
A subclass of ANTIFREEZE PROTEINS that are globular, 6.5 kDa in size and contain compact beta-sheet structures.

Antifreeze Proteins, Type IV [M0068034]
A subclass of ANTIFREEZE PROTEINS that contain four amphipathic alpha-helices folded into an antiparallel helix bundle.

Antigen T Cell Receptor, beta Chain [M0025430]

Antigen T Cell Receptor, gamma Chain [M0025427]

Antigen, B7 [M0483212]

Antigen-Antibody Complex [M0001400]
The complex formed by the binding of antigen and antibody molecules. The deposition of large antigen-antibody complexes leading to tissue damage causes IMMUNE COMPLEX DISEASES.

Antigens, CD1 [M0028319]
Glycoproteins expressed on cortical thymocytes and on some dendritic cells and B-cells. Their structure is similar to that of MHC Class I and their function has been postulated as similar also. CD1 antigens are highly specific markers for human LANGERHANS CELLS.

Antigens, CD11 [M0028198]
A group of three different alpha chains (CD11a, CD11b, CD11c) that are associated with an invariant CD18 beta chain (ANTIGENS, CD18). The three resulting leukocyte-adhesion molecules (RECEPTORS, LEUKOCYTE ADHESION) are LYMPHOCYTE FUNCTION-ASSOCIATED ANTIGEN-1; MACROPHAGE-1 ANTIGEN; and ANTIGEN, P150,95.

Antigens, CD11a [M0024682]
An alpha-integrin subunit found on lymphocytes, granulocytes, macrophages and monocytes. It combines with the integrin beta2 subunit (CD18 ANTIGEN) to form LYMPHOCYTE FUNCTION-ASSOCIATED ANTIGEN-1.

Antigens, CD11b [M0419189]
A CD antigen that contains a conserved I domain which is involved in ligand binding. When combined with CD18 the two subunits form MACROPHAGE-1 ANTIGEN.

Antigens, CD11c [M0024680]
An integrin alpha subunit of approximately 150-kDa molecular weight. It is expressed at high levels on monocytes and combines with CD18 ANTIGEN to form the cell surface receptor INTEGRIN ALPHAXBETA2. The subunit contains a conserved I-domain which is characteristic of several of alpha integrins.

Antigens, CD13 [M0028180]
Zinc-binding metalloproteases that are members of the type II integral membrane metalloproteases. They are expressed by GRANULOCYTES; MONOCYTES; and their precursors as well as by various non-hematopoietic cells. They release an N-terminal amino acid from a peptide, amide or arylamide.

Antigens, CD137 [M0214853]
A member of the tumor necrosis factor receptor superfamily that is specific for 4-1BB LIGAND. It is found in a variety of immune cell types including activated T-LYMPHOCYTES; NATURAL KILLER CELLS; and DENDRITIC CELLS. Activation of the receptor on T-LYMPHOCYTES plays a role in their expansion, production of cytokines and survival. Signaling by the activated receptor occurs through its association with TNF RECEPTOR-ASSOCIATED FACTORS.

Antigens, CD14 [M0028320]
Glycolipid-anchored membrane glycoproteins expressed on cells of the myelomonocyte lineage including monocytes, macrophages, and some granulocytes. They function as receptors for the complex of lipopolysaccharide (LPS) and LPS-binding protein.

Antigens, CD146 [M0172205]
A cell adhesion molecule of the immunoglobulin superfamily that is expressed in ENDOTHELIAL CELLS and is involved in INTERCELLULAR JUNCTIONS.

Antigens, CD147 [M0177703]
A widely distributed cell surface transmembrane glycoprotein that stimulates the synthesis of MATRIX METALLOPROTEINASES. It is found at high levels on the surface of malignant NEOPLASMS and may play a role as a mediator of malignant cell behavior.

Antigens, CD15 [M0024834]
Carbohydrate antigen which is accumulated in various human cancer tissues and secreted into the blood stream. The carbohydrate moiety can be further modified with fucose or sialic acid. Monoclonal antibodies have been determined which can discriminate each subgroup of this antigen in the sera of cancer patients. Sialyl SSEA-1 antigen is particularly elevated in the sera of patients with a variety of tumors.

Antigens, CD16 [M0026479]

Antigens, CD164 [M0482205]
A sialomucin protein that functions as a cell adhesion molecule. It is a negative regulator of certain types of HEMATOPOIETIC STEM CELLS.

Antigens, CD18 [M0028177]
Cell-surface glycoprotein beta-chains that are non-covalently linked to specific alpha-chains of the CD11 family of leukocyte-adhesion molecules (RECEPTORS, LEUKOCYTE-ADHESION). A defect in the gene encoding CD18 causes LEUKOCYTE-ADHESION DEFICIENCY SYNDROME.

Antigens, CD19 [M0028310]
Differentiation antigens expressed on B-lymphocytes and B-cell precursors. They are involved in regulation of B-cell proliferation.

Antigens, CD2 [M0028149]
Glycoprotein members of the immunoglobulin superfamily which participate in T-cell adhesion and activation. They are expressed on most peripheral T-lymphocytes, natural killer cells, and thymocytes, and function as co-receptors or accessory molecules in the T-cell receptor complex.

Antigens, CD20 [M0028321]
Unglycosylated phosphoproteins expressed only on B-cells. They are regulators of transmembrane Ca2+ conductance and thought to play a role in B-cell activation and proliferation.

Antigens, CD22 [M0153861]
A lectin and cell adhesion molecule found in B-LYMPHOCYTES. It interacts with SIALIC ACIDS and mediates signaling from B-CELL ANTIGEN RECEPTORS.

Antigens, CD24 [M0172384]
A cell adhesion protein that was originally identified as a heat stable antigen in mice. It is involved in METASTASIS and is highly expressed in many NEOPLASMS.

Antigens, CD26 [M0028176]
Cell-surface glycoproteins and serine protease, also known as dipeptidyl-peptidase IV, that play a role in T-lymphocyte activation. CD26 binds to adenosine deaminase on the T-cell surface. EC 3.4.14.5

Antigens, CD27 [M0027333]
A member of the tumor necrosis factor receptor superfamily found on most T-LYMPHOCYTES. Activation of the receptor by CD70 ANTIGEN results in the increased proliferation of CD4-POSITIVE T-LYMPHOCYTES and CD8-POSITIVE T-LYMPHOCYTES. Signaling by the activated receptor occurs through its association with TNF RECEPTOR-ASSOCIATED FACTORS.

Antigens, CD28 [M0027304]
T-cell differentiation antigens that serve as the receptors for the B7 antigen (ANTIGENS, CD80) which modulates T-cell lymphokine production.

Antigens, CD29 [M0028390]
Integrin beta-1 chains which are expressed as heterodimers that are noncovalently associated with specific alpha-chains of the CD49 family (CD49a-f). CD29 is expressed on resting and activated leukocytes and is a marker for all of the very late activation antigens on cells. (from: Barclay et al., The Leukocyte Antigen FactsBook, 1993, p164)

Antigens, CD3 [M0026174]
Complex of at least five membrane-bound polypeptides in mature T-lymphocytes that are non-covalently associated with one another and with the T-cell receptor (RECEPTORS, ANTIGEN, T-CELL). The CD3 complex includes the gamma, delta, epsilon, zeta, and eta chains (subunits). When antigen binds to the T-cell receptor, the CD3 complex transduces the activating signals to the cytoplasm of the T-cell. The CD3 gamma and delta chains (subunits) are separate from and not related to the gamma/delta chains of the T-cell receptor (RECEPTORS, ANTIGEN, T-CELL, GAMMA-DELTA).

Antigens, CD30 [M0026795]
A member of the tumor necrosis factor receptor superfamily that may play a role in the regulation of NF-KAPPA B and APOPTOSIS. They are found on activated T-LYMPHOCYTES; B-LYMPHOCYTES; NEUTROPHILS; EOSINOPHILS; MAST CELLS and NK CELLS. Overexpression of CD30 antigen in hematopoietic malignancies make the antigen clinically useful as a biological tumor marker. Signaling of the receptor occurs through its association with TNF RECEPTOR-ASSOCIATED FACTORS.

Antigens, CD31 [M0028878]
Cell adhesion molecules present on virtually all monocytes, platelets, and granulocytes. CD31 is highly expressed on endothelial cells and concentrated at the junctions between them.

Antigens, CD34 [M0028322]
Glycoproteins found on immature hematopoietic cells and endothelial cells. They are the only molecules to date whose expression within the blood system is restricted to a small number of progenitor cells in the bone marrow.

Antigens, CD36 [M0028325]
Leukocyte differentiation antigens and major platelet membrane glycoproteins present on MONOCYTES; ENDOTHELIAL CELLS; PLATELETS; and mammary EPITHELIAL CELLS. They play major roles in CELL ADHESION; SIGNAL TRANSDUCTION; and regulation of angiogenesis. CD36 is a receptor for THROMBOSPONDINS and can act as a scavenger receptor that recognizes and transports oxidized LIPOPROTEINS and FATTY ACIDS.

Antigens, CD38 [M0160285]
A bifunctional enzyme that catalyzes the synthesis and HYDROLYSIS of CYCLIC ADP-RIBOSE (cADPR) from NAD+ to ADP-RIBOSE. It is a cell surface molecule which is predominantly expressed on LYMPHOID CELLS and MYELOID CELLS.

Antigens, CD4 [M0024088]
55-kDa antigens found on HELPER-INDUCER T-LYMPHOCYTES and on a variety of other immune cell types. CD4 antigens are members of the immunoglobulin supergene family and are implicated as associative recognition elements in MAJOR HISTOCOMPATIBILITY COMPLEX class II-restricted immune responses. On T-lymphocytes they define the helper/inducer subset. CD4 antigens also serve as INTERLEUKIN-15 receptors and bind to the HIV receptors, binding directly to the HIV ENVELOPE PROTEIN GP120.

Antigens, CD40 [M0028391]
A member of the tumor necrosis factor receptor superfamily with specificity for CD40 LIGAND. It is found on mature B-LYMPHOCYTES and some EPITHELIAL CELLS, lymphoid DENDRITIC CELLS. Evidence suggests that CD40-dependent activation of B-cells is important for generation of memory B-cells within the germinal centers. Mutations of the gene for CD40 antigen result in HYPER-IGM IMMUNODEFICIENCY SYNDROME, TYPE 3. Signaling of the receptor occurs through its association with TNF RECEPTOR-ASSOCIATED FACTORS.

Antigens, CD43 [M0123558]
A sialic acid-rich protein and an integral cell membrane mucin. It plays an important role in activation of T-LYMPHOCYTES.

Antigens, CD44 [M0028330]
Acidic sulfated integral membrane glycoproteins expressed in several alternatively spliced and variable glycosylated forms on a wide variety of cell types including mature T-cells, B-cells, medullary thymocytes, granulocytes, macrophages, erythrocytes, and fibroblasts. CD44 antigens are the principle cell surface receptors for hyaluronate and this interaction mediates binding of lymphocytes to high endothelial venules. (From Abbas et al., Cellular and Molecular Immunology, 2d ed, p156)

Antigens, CD45 [M0026536]
High-molecular weight glycoproteins uniquely expressed on the surface of all leukocytes and their hemopoietic progenitors. The CD45 family consists of multiple members that are all products of a single gene. CD45 expression is necessary for signaling through the T-cell receptor.

Antigens, CD46 [M0148714]
A ubiquitously expressed complement receptor that binds COMPLEMENT C3B and COMPLEMENT C4B and serves as a cofactor for their inactivation. CD46 also interacts with a wide variety of pathogens and mediates immune response.

Antigens, CD47 [M0221607]
A ubiquitously expressed membrane glycoprotein. It interacts with a variety of INTEGRINS and mediates responses to EXTRACELLULAR MATRIX PROTEINS.

Antigens, CD5 [M0028326]
Glycoproteins expressed on all mature T-cells, thymocytes, and a subset of mature B-cells. Antibodies specific for CD5 can enhance T-cell receptor-mediated T-cell activation. The B-cell-specific molecule CD72 is a natural ligand for CD5. (From Abbas et al., Cellular and Molecular Immunology, 2d ed, p156)

Antigens, CD55 [M0028328]
Glycoproteins broadly distributed among hematopoietic and non-hematopoietic cells. CD55 prevents the assembly of C3 convertase or accelerates the disassembly of preformed convertase, thus blocking the formation of the membrane attack complex.

Antigens, CD56 [M0028376]
The 140 kDa isoform of NCAM (neural cell adhesion molecule) containing a transmembrane domain and short cytoplasmic tail. It is expressed by all lymphocytes mediating non-MHC restricted cytotoxicity and is present on some neural tissues and tumors.

Antigens, CD57 [M0028329]
Oligosaccharide antigenic determinants found principally on NK cells and T-cells. Their role in the immune response is poorly understood.

Antigens, CD58 [M0028339]
Glycoproteins with a wide distribution on hematopoietic and non-hematopoietic cells and strongly expressed on macrophages. CD58 mediates cell adhesion by binding to CD2; (ANTIGENS, CD2); and this enhances antigen-specific T-cell activation.

Antigens, CD59 [M0028327]
Small glycoproteins found on both hematopoietic and non-hematopoietic cells. CD59 restricts the cytolytic activity of homologous complement by binding to C8 and C9 and blocking the assembly of the membrane attack complex. (From Barclay et al., The Leukocyte Antigen FactsBook, 1993, p234)

Antigens, CD70 [M0216394]
A transmembrane protein belonging to the tumor necrosis factor superfamily that specifically binds to CD27 ANTIGEN. It is found on activated T-LYMPHOCYTES; B-LYMPHOCYTES; and DENDRITIC CELLS where it plays a role in stimulating the proliferation of CD4-POSITIVE T-LYMPHOCYTES and CD8-POSITIVE T-LYMPHOCYTES.

Antigens, CD79 [M0178020]
A component of the B-cell antigen receptor that is involved in B-cell antigen receptor heavy chain transport to the PLASMA MEMBRANE. It is expressed almost exclusively in B-LYMPHOCYTES and serves as a useful marker for B-cell NEOPLASMS.

Antigens, CD79a [M0482197]

Antigens, CD79b [M0187606]

Antigens, CD8 [M0025621]
Differentiation antigens found on thymocytes and on cytotoxic and suppressor T-lymphocytes. CD8 antigens are members of the immunoglobulin supergene family and are associative recognition elements in MHC (Major Histocompatibility Complex) Class I-restricted interactions.

Antigens, CD80 [M0027327]
The natural ligand for the T-cell antigen CD28; (ANTIGENS, CD28); mediating T- and B-cell adhesion. CD80 is expressed on activated B-cells and gamma-interferon-stimulated monocytes. The binding of CD80 to CD28 and CTLA-4 provides a co-stimulatory signal to T-cells and leads to greatly upregulated lymphokine production.

Antigens, CD86 [M0223248]
A CD antigen that plays a role in T-lymphocyte proliferation and interleukin 2 production. It is a co-stimulatory ligand for the CD28 ANTIGEN on T-LYMPHOCYTES and initiates T-cell activation and immune response.

Antigens, CD94 [M0253282]
A C-type lectin that associates with NKG2 proteins to form receptors for HLA-E antigen on NATURAL KILLER CELLS.

Antigens, CD95 [M0028392]
A tumor necrosis factor receptor subtype found in a variety of tissues and on activated LYMPHOCYTES. It has specificity for FAS LIGAND and plays a role in regulation of peripheral immune responses and APOPTOSIS. Multiple isoforms of the protein exist due to multiple ALTERNATIVE SPLICING. The activated receptor signals via a conserved death domain that associates with specific TNF RECEPTOR-ASSOCIATED FACTORS in the CYTOPLASM.

Antigens, CD98 [M0159086]
A heterodimeric protein that is a cell surface antigen associated with lymphocyte activation. The initial characterization of this protein revealed one identifiable heavy chain (ANTIGENS, CD98 HEAVY CHAIN) and an indeterminate smaller light chain. It is now known that a variety of light chain subunits (ANTIGENS, CD98 LIGHT CHAINS) can dimerize with the heavy chain. Depending upon its light chain composition a diverse array of functions can be found for this protein. Functions include: type L amino acid transport, type y+L amino acid transport and regulation of cellular fusion.

Antigens, CD98 Heavy Chain [M0379771]
A transmembrane glycoprotein subunit that can dimerize with a variety of light chain subunits (ANTIGENS, CD98 LIGHT CHAINS). This protein subunit serves a diverse array of functions including amino acid transport and cell fusion. Its function is altered depending which of the light chain subunits it interacts with.

Antigens, CD98 Light Chains [M0379850]
A family of light chains that bind to the CD98 heavy chain (ANTIGENS, CD98 HEAVY CHAIN) to form a heterodimer. They convey functional specificity to the protein.

Antigens, Dermatophagoides [M0419493]
Antigens from the house dust mites (DERMATOPHAGOIDES), mainly D. farinae and D. pteronyssinus. They are proteins, found in mite feces or mite extracts, that can cause ASTHMA and other allergic diseases such as perennial rhinitis (RHINITIS, ALLERGIC, PERENNIAL) and atopic dermatitis (DERMATITIS, ATOPIC). More than 11 groups of Dermatophagoides ALLERGENS have been defined. Group I allergens, such as Der f I and Der p I from the above two species, are among the strongest mite immunogens in humans.

Antigens, Dermatophagoides farinae [M0116078]

Antigens, Dermatophagoides pteronyssinus [M0116080]

Antigens, Differentiation, Myelomonocytic [M0023376]
Surface antigens expressed on myeloid cells of the granulocyte-monocyte-histiocyte series during differentiation. Analysis of their reactivity in normal and malignant myelomonocytic cells is useful in identifying and classifying human leukemias and lymphomas.

Antigens, Differentiation, T-Lymphocyte [M0001415]
Antigens expressed on the cell membrane of T-lymphocytes during differentiation, activation, and normal and neoplastic transformation. Their phenotypic characterization is important in differential diagnosis and studies of thymic ontogeny and T-cell function.

Antigens, Fos-Related [M0025544]

Antigens, Synthetic [M0022458]

Antigens, Thy-1 [M0028146]
A group of differentiation surface antigens, among the first to be discovered on thymocytes and T-lymphocytes. Originally identified in the mouse, they are also found in other species including humans, and are expressed on brain neurons and other cells.

Antilymphoblast Globulins [M0001460]

Antilymphocyte Antibodies [M0001461]

Antilymphocyte Globulin [M0001462]

Antilymphocyte Immunoglobulin [M0001463]

Antilymphocyte Serum [M0001464]
Serum containing GAMMA-GLOBULINS which are antibodies for lymphocyte ANTIGENS. It is used both as a test for HISTOCOMPATIBILITY and therapeutically in TRANSPLANTATION.

Antilysin [M0011907]

Antimicrobial Cationic Peptides [M0093656]
Small cationic peptides that are an important component, in most species, of early innate and induced defenses against invading microbes. In animals they are found on mucosal surfaces, within phagocytic granules, and on the surface of the body. They are also found in insects and plants. Among others, this group includes the DEFENSINS, protegrins, tachyplesins, and thionins.

Antimicrobial Peptides, Neutrophil [M0093647]

Antipain [M0001492]
An oligopeptide produced by various bacteria which acts as a protease inhibitor.

Antiplasmin [M0001495]
A member of the serpin superfamily found in human plasma that inhibits the lysis of fibrin clots which are induced by plasminogen activator. It is a glycoprotein, molecular weight approximately 70,000 that migrates in the alpha 2 region in immunoelectrophoresis. It is the principal plasmin inactivator in blood, rapidly forming a very stable complex with plasmin.

Antiporters [M0027075]
Membrane transporters that co-transport two or more dissimilar molecules in the opposite direction across a membrane. Usually the transport of one ion or molecule is against its electrochemical gradient and is "powered" by the movement of another ion or molecule with its electrochemical gradient.

Antithrombin III [M0001509]
A plasma alpha 2 glycoprotein that accounts for the major antithrombin activity of normal plasma and also inhibits several other enzymes; it was formerly called Antithrombin II (AT II) which has now been shown to be identical to AT III; ANTITHROMBIN III DEFICIENCY, hereditary or acquired, results in thromboembolism. It is a member of the serpin superfamily. Some authors use the term antithrombin to refer to antithrombin III.

Antithrombin III, Human Plasma [M0330782]

Antithrombin III-Alpha [M0434010]

Antithrombins [M0001510]
An endogenous family of proteins belonging to the serpin superfamily that neutralizes the action of thrombin. Six naturally occurring antithrombins have been identified and are designated by Roman numerals I to VI. Of these, Antithrombin I (see FIBRIN) and ANTITHROMBIN III appear to be of major importance.

Antithymoglobulin [M0001465]

Antril [M0148640]

ApaCI Endonuclease [M0023457]

Apamin [M0001564]
A highly neurotoxic polypeptide from the venom of the honey bee (Apis mellifera). It consists of 18 amino acids with two disulfide bridges and causes hyperexcitability resulting in convulsions and respiratory paralysis.

APH(3')-IIb [M0029499]

APH(3')-IIIa [M0029497]

APHVII [M0029500]

Apo C-III-2 [M0073729]

Apo-Baclofen [M0454555]

Apo-Desmopressin [M0492527]

Apo-Methyldopa [M0474247]

ApoC-III [M0489164]

Apocytochrome b [M0071379]

Apocytochrome b5 [M0447731]

Apocytochrome b6 [M0193535]

Apocytochrome C [M0116739]

Apocytochrome f [M0147616]

Apoenzymes [M0001591]
The protein components of enzyme complexes (HOLOENZYMES). An apoenzyme is the holoenzyme minus any cofactors (ENZYME COFACTORS) or prosthetic groups required for the enzymatic function.

Apoferritins [M0001592]
The protein components of ferritins. Apoferritins are shell-like structures containing nanocavities and ferroxidase activities. Apoferritin shells are composed of 24 subunits, heteropolymers in vertebrates and homopolymers in bacteria. In vertebrates, there are two types of subunits, light chain and heavy chain. The heavy chain contains the ferroxidase activity.

Apolipoprotein A-I [M0025348]
The most abundant protein component of HIGH DENSITY LIPOPROTEINS or HDL. This protein serves as an acceptor for CHOLESTEROL released from cells thus promoting efflux of cholesterol to HDL then to the LIVER for excretion from the body (reverse cholesterol transport). It also acts as a cofactor for LECITHIN CHOLESTEROL ACYLTRANSFERASE that forms CHOLESTEROL ESTERS on the HDL particles. Mutations of this gene APOA1 cause HDL deficiency, such as in FAMILIAL ALPHA LIPOPROTEIN DEFICIENCY DISEASE and in some patients with TANGIER DISEASE.

Apolipoprotein A-I Isoprotein-2 [M0087282]

Apolipoprotein A-I Isoprotein-4 [M0087283]

Apolipoprotein A-I Isoproteins [M0087284]
Variants of apolipoprotein A-I. They include secreted propeptide form (isoprotein 2), the converted plasma form (isoprotein-4), and those with various substitutions or deletions.

Apolipoprotein A-II [M0025349]
The second most abundant protein component of HIGH DENSITY LIPOPROTEINS or HDL. It has a high lipid affinity and is known to displace APOLIPOPROTEIN A-I from HDL particles and generates a stable HDL complex. ApoA-II can modulate the activation of LECITHIN CHOLESTEROL ACYLTRANSFERASE in the presence of APOLIPOPROTEIN A-I, thus affecting HDL metabolism.

Apolipoprotein A-II Isoproteins [M0492280]

Apolipoprotein B-100 [M0114886]
A 513-kDa protein synthesized in the LIVER. It serves as the major structural protein of low-density lipoproteins (LIPOPROTEINS, LDL; LIPOPROTEINS, VLDL). It is the ligand for the LDL receptor (RECEPTORS, LDL) that promotes cellular binding and internalization of LDL particles.

Apolipoprotein B-48 [M0114883]
A 241-kDa protein synthesized only in the INTESTINES. It serves as a structural protein of CHYLOMICRONS. Its exclusive association with chylomicron particles provides an indicator of intestinally derived lipoproteins in circulation. Apo B-48 is a shortened form of apo B-100 and lacks the LDL-receptor region.

Apolipoprotein C-I [M0073728]
A 6.6-kDa protein component of VERY-LOW-DENSITY LIPOPROTEINS; INTERMEDIATE-DENSITY LIPOPROTEINS; and HIGH-DENSITY LIPOPROTEINS. Apo C-I displaces APO E from lipoproteins, modulate their binding to receptors (RECEPTORS, LDL), and thereby decrease their clearance from plasma. Elevated Apo C-I levels are associated with HYPERLIPOPROTEINEMIA and ATHEROSCLEROSIS.

Apolipoprotein C-I Precursor [M0123384]

Apolipoprotein C-II [M0066119]
A 9-kDa protein component of VERY-LOW-DENSITY LIPOPROTEINS. It contains a cofactor for LIPOPROTEIN LIPASE and activates several triacylglycerol lipases. The association of Apo C-II with plasma CHYLOMICRONS; VLDL, and HIGH-DENSITY LIPOPROTEINS is reversible and changes rapidly as a function of triglyceride metabolism. Clinically, Apo C-II deficiency is similar to lipoprotein lipase deficiency (HYPERLIPOPROTEINEMIA TYPE I) and is therefore called hyperlipoproteinemia type IB.

Apolipoprotein C-III [M0073736]
A 9-kDa protein component of VERY-LOW-DENSITY LIPOPROTEINS and CHYLOMICRON REMNANTS. Apo C-III, synthesized in the liver, is an inhibitor of LIPOPROTEIN LIPASE. Apo C-III modulates the binding of chylomicron remnants and VLDL to receptors (RECEPTORS, LDL) thus decreases the uptake of triglyceride-rich particles by the liver cells and subsequent degradation. The normal Apo C-III is glycosylated. There are several polymorphic forms with varying amounts of SIALIC ACID (Apo C-III-0, Apo C-III-1, and Apo C-III-2).

Apolipoprotein C-III-0 [M0073731]

Apolipoprotein C-III-1 [M0073732]

Apolipoprotein E Isoproteins [M0114996]

Apolipoprotein E2 [M0119983]
One of three major isoforms of apolipoprotein E. In humans, Apo E2 differs from APOLIPOPROTEIN E3 at one residue 158 where arginine is replaced by cysteine (R158--C). In contrast to Apo E3, Apo E2 displays extremely low binding affinity for LDL receptors (RECEPTORS, LDL) which mediate the internalization and catabolism of lipoprotein particles in liver cells. ApoE2 allelic homozygosity is associated with HYPERLIPOPROTEINEMIA TYPE III.

Apolipoprotein E3 [M0091671]
A 34-kDa glycosylated protein. A major and most common isoform of apolipoprotein E. Therefore, it is also known as apolipoprotein E (ApoE). In human, Apo E3 is a 299-amino acid protein with a cysteine at the 112 and an arginine at the 158 position. It is involved with the transport of TRIGLYCERIDES; PHOSPHOLIPIDS; CHOLESTEROL; and CHOLESTERYL ESTERS in and out of the cells.

Apolipoprotein E4 [M0108562]
A major and the second most common isoform of apolipoprotein E. In humans, Apo E4 differs from APOLIPOPROTEIN E3 at only one residue 112 (cysteine is replaced by arginine), and exhibits a lower resistance to denaturation and greater propensity to form folded intermediates. Apo E4 is a risk factor for ALZHEIMER DISEASE and CARDIOVASCULAR DISEASES.

Apolipoproteins [M0001593]
Protein components on the surface of LIPOPROTEINS. They form a layer surrounding the hydrophobic lipid core. There are several classes of apolipoproteins with each playing a different role in lipid transport and LIPID METABOLISM. These proteins are synthesized mainly in the LIVER and the INTESTINES.

Apolipoproteins A [M0001594]
Structural proteins of the alpha-lipoproteins (HIGH DENSITY LIPOPROTEINS), including APOLIPOPROTEIN A-I and APOLIPOPROTEIN A-II. They can modulate the activity of LECITHIN CHOLESTEROL ACYLTRANSFERASE. These apolipoproteins are low in atherosclerotic patients. They are either absent or present in extremely low plasma concentration in TANGIER DISEASE.

Apolipoproteins B [M0001596]
Major structural proteins of triacylglycerol-rich LIPOPROTEINS. There are two forms, apolipoprotein B-100 and apolipoprotein B-48, both derived from a single gene. ApoB-100 expressed in the liver is found in low-density lipoproteins (LIPOPROTEINS, LDL; LIPOPROTEINS, VLDL). ApoB-48 expressed in the intestine is found in CHYLOMICRONS. They are important in the biosynthesis, transport, and metabolism of triacylglycerol-rich lipoproteins. Plasma Apo-B levels are high in atherosclerotic patients but non-detectable in ABETALIPOPROTEINEMIA.

Apolipoproteins C [M0001599]
A group of apolipoproteins that can readily exchange among the various classes of lipoproteins (HDL; VLDL; CHYLOMICRONS). After lipolysis of TRIGLYCERIDES on VLDL and chylomicrons, Apo-C proteins are normally transferred to HDL. The subtypes can modulate remnant binding to receptors, LECITHIN CHOLESTEROL ACYLTRANSFERASE, or LIPOPROTEIN LIPASE.

Apolipoproteins D [M0082573]
A glycoprotein component of HIGH-DENSITY LIPOPROTEIN that transports small hydrophobic ligands including CHOLESTEROL and STEROLS. It occurs in the macromolecular complex with LECITHIN CHOLESTEROL ACYLTRANSFERASE. Apo D is expressed in and secreted from a variety of tissues such as liver, placenta, brain tissue and others.

Apolipoproteins E [M0001601]
A class of protein components which can be found in several lipoproteins including HIGH-DENSITY LIPOPROTEINS; VERY-LOW-DENSITY LIPOPROTEINS; and CHYLOMICRONS. Synthesized in most organs, Apo E is important in the global transport of lipids and cholesterol throughout the body. Apo E is also a ligand for LDL receptors (RECEPTORS, LDL) that mediates the binding, internalization, and catabolism of lipoprotein particles in cells. There are several allelic isoforms (such as E2, E3, and E4). Deficiency or defects in Apo E are causes of HYPERLIPOPROTEINEMIA TYPE III.

Apoprotein(a) [M0001595]
A large and highly glycosylated protein constituent of LIPOPROTEIN (A). It has very little affinity for lipids but forms disulfide-linkage to APOLIPOPROTEIN B100. Apoprotein(a) has SERINE PROTEINASE activity and can be of varying sizes from 400- to 800-kDa. It is homologous to PLASMINOGEN and is known to modulate THROMBOSIS and FIBRINOLYSIS.

Apoproteins [M0001605]
The protein components of a number of complexes, such as enzymes (APOENZYMES), ferritin (APOFERRITINS), or lipoproteins (APOLIPOPROTEINS).

Apoproteins B [M0001598]

Apoproteins C [M0001600]

Apoproteins E [M0001602]

Apoptosis Inducing Factor [M0301106]
A flavoprotein that functions as a powerful antioxidant in the MITOCHONDRIA and promotes APOPTOSIS when released from the mitochondria. In mammalian cells AIF is released in response to pro-apoptotic protein members of the bcl-2 protein family. It translocates to the CELL NUCLEUS and binds DNA to stimulate CASPASE-independent CHROMATIN condensation.

Apoptosis Inducing Proteins [M0480020]

Apoptosis Inhibiting Proteins [M0480019]

Apoptosis Regulatory Proteins [M0478975]
A large group of proteins that control APOPTOSIS. This family of proteins includes many ONCOGENE PROTEINS as well as a wide variety of classes of INTRACELLULAR SIGNALING PEPTIDES AND PROTEINS such as CASPASES.

Apoptosis, Extrinsic Pathway [M0493496]
Apoptosis that is triggered via CELL SURFACE RECEPTORS such as TUMOR NECROSIS FACTOR RECEPTORS and DEATH DOMAIN RECEPTORS.

Apoptosis, Intrinsic Pathway [M0493497]
Apoptosis that is triggered via cell stress and mitochondrial damage.

Apoptosomes [M0493498]
Multimeric protein complexes formed in the CYTOSOL that play a role in the activation of APOPTOSIS. They can occur when MITOCHONDRIA become damaged due to cell stress and release CYTOCHROME C. Cytosolic cytochrome C associates with APOPTOTIC PROTEASE-ACTIVATING FACTOR 1 to form the apoptosomal protein complex. The apoptosome signals apoptosis by binding to and activating specific INITIATOR CASPASES such as CASPASE 9.

Apoptotic Protease-Activating Factor 1 [M0279898]
A CARD signaling adaptor protein that plays a role in the mitochondria-stimulated apoptosis (APOPTOSIS, INTRINSIC PATHWAY). It binds to CYTOCHROME C in the CYTOSOL to form an APOPTOSOMAL PROTEIN COMPLEX and activates INITIATOR CASPASES such as CASPASE 9.

Apotransketolase [M0021824]

AprA-Subtilisin [M0020686]

Aprotinin [M0011905]
A single-chain polypeptide derived from bovine tissues consisting of 58 amino-acid residues. It is an inhibitor of proteolytic enzymes including CHYMOTRYPSIN; KALLIKREIN; PLASMIN; and TRYPSIN. It is used in the treatment of HEMORRHAGE associated with raised plasma concentrations of plasmin. It is also used to reduce blood loss and transfusion requirements in patients at high risk of major blood loss during and following open heart surgery with EXTRACORPOREAL CIRCULATION. (Reynolds JEF(Ed): Martindale: The Extra Pharmacopoeia (electronic version). Micromedex, Inc, Englewood, CO, 1995)

Aptamers, Peptide [M0483502]
Peptide sequences, generated by iterative rounds of SELEX APTAMER TECHNIQUE, that bind to a target molecule specifically and with high affinity.

Apyrase [M0001635]
A calcium-activated enzyme that catalyzes the hydrolysis of ATP to yield AMP and orthophosphate. It can also act on ADP and other nucleoside triphosphates and diphosphates. EC 3.6.1.5.

Aquaglyceroporins [M0480377]
A subgroup of aquaporins that transport WATER; GLYCEROL; and other small solutes across CELL MEMBRANES.

Aquaporin 1 [M0195494]
Aquaporin 1 forms a water-specific channel that is constitutively expressed at the PLASMA MEMBRANE of ERYTHROCYTES and KIDNEY TUBULES, PROXIMAL. It provides these cells with a high permeability to WATER. In humans polymorphisms of this protein result in the Colton blood group antigen.

Aquaporin 2 [M0213077]
Aquaporin 2 is a water-specific channel protein that is expressed in KIDNEY COLLECTING DUCTS. The translocation of aquaporin 2 to the apical PLASMA MEMBRANE is regulated by VASOPRESSIN, and MUTATIONS in AQP2 have been implicated in a variety of kidney disorders including DIABETES INSIPIDUS.

Aquaporin 3 [M0233100]
Aquaporin 3 is an aquaglyceroporin that is expressed in the KIDNEY COLLECTING DUCTS and is constitutively localized at the basolateral MEMBRANE.

Aquaporin 4 [M0241190]
Aquaporin 4 is the major water-selective channel in the CENTRAL NERVOUS SYSTEM of mammals.

Aquaporin 5 [M0259619]
Aquaporin 5 is a water-specific channel protein that is expressed primarily in alveolar, tracheal, and upper bronchial EPITHELIUM. It plays an important role in maintaining water HOMEOSTASIS in the LUNGS and may also regulate release of SALIVA and TEARS in the SALIVARY GLANDS and the LACRIMAL GLAND.

Aquaporin 6 [M0213073]
Aquaporin 6 is an aquaglyceroporin that is found primarily in KIDNEY COLLECTING DUCTS. AQP6 protein functions as an anion-selective channel.

Aquaporins [M0029981]
A class of porins that allow the passage of WATER and other small molecules across CELL MEMBRANES.

Arabidopsis Proteins [M0385133]
Proteins that originate from plants species belonging to the genus ARABIDOPSIS. The most intensely studied species of Arabidopsis, Arabidopsis thaliana, is commonly used in laboratory experiments.

Arabidopsis thaliana Proteins [M0385134]

AraC Transcription Factor [M0087638]
A transcription factor found in BACTERIA that positively and negatively regulates the expression of proteins required for the uptake and catabolism of L-ARABINOSE.

Arachidonate 12-Lipoxygenase [M0001646]
An enzyme that catalyzes the oxidation of arachidonic acid to yield 12-hydroperoxyarachidonate (12-HPETE) which is itself rapidly converted by a peroxidase to 12-hydroxy-5,8,10,14-eicosatetraenoate (12-HETE). The 12-hydroperoxides are preferentially formed in platelets. EC 1.13.11.31.

Arachidonate 15-Lipoxygenase [M0001647]
An enzyme that catalyzes the oxidation of arachidonic acid to yield 15-hydroperoxyarachidonate (15-HPETE) which is rapidly converted to 15-hydroxy-5,8,11,13-eicosatetraenoate (15-HETE). The 15-hydroperoxides are preferentially formed in neutrophils and lymphocytes. EC 1.13.11.33.

Arachidonate 5-Lipoxygenase [M0001648]
An enzyme that catalyzes the oxidation of arachidonic acid to yield 5-hydroperoxyarachidonate (5-HPETE) which is rapidly converted by a peroxidase to 5-hydroxy-6,8,11,14-eicosatetraenoate (5-HETE). The 5-hydroperoxides are preferentially formed in leukocytes. EC 1.13.11.34.

Arachidonate Lipoxygenases [M0001645]
Enzymes catalyzing the oxidation of arachidonic acid to hydroperoxyarachidonates (HPETES). These products are then rapidly converted by a peroxidase to hydroxyeicosatetraenoic acids (HETES). The positional specificity of the enzyme reaction varies from tissue to tissue. The final lipoxygenase pathway leads to the leukotrienes. EC 1.13.11.- .

Arachidonoyl-Diacylglycerol Kinase [M0029464]

Archaeal Proteins [M0029453]
Proteins found in any species of archaeon.

Archaeal Rhodopsins [M0375053]

Ardeydorm [M0477040]

Arginase [M0001679]
A ureahydrolase that catalyzes the hydrolysis of arginine or canavanine to yield L-ornithine (ORNITHINE) and urea. Deficiency of this enzyme causes HYPERARGININEMIA. EC 3.5.3.1.

Arginase A1 [M0001680]

Arginase A4 [M0001681]

Arginine [M0001683]
An essential amino acid that is physiologically active in the L-form.

Arginine Kinase [M0001686]
An enzyme that catalyzes the phosphorylation of the guanidine nitrogen of arginine in the presence of ATP and a divalent cation with formation of phosphorylarginine and ADP. EC 2.7.3.3.

Arginine Vasopressin [M0001691]
The predominant form of mammalian antidiuretic hormone. It is a nonapeptide containing an ARGININE at residue 8 and two disulfide-linked CYSTEINES at residues of 1 and 6. Arg-vasopressin is used to treat DIABETES INSIPIDUS or to improve vasomotor tone and BLOOD PRESSURE.

Arginine-tRNA Ligase [M0001690]
An enzyme that activates arginine with its specific transfer RNA. EC 6.1.1.19.

Argininosuccinate Lyase [M0001687]
An enzyme of the urea cycle which splits argininosuccinate to fumarate plus arginine. Its absence leads to the metabolic disease argininosuccinic acidemia in man. EC 4.3.2.1.

Argininosuccinate Synthase [M0001688]
An enzyme of the urea cycle that catalyzes the formation of argininosuccinic acid from citrulline and aspartic acid in the presence of ATP. Absence or deficiency of this enzyme causes the metabolic disease CITRULLINEMIA in humans. EC 6.3.4.5.

Argininosuccinic Acid [M0001689]
This amino acid is formed during the urea cycle from citrulline, aspartate and ATP. This reaction is catalyzed by argininosuccinic acid synthetase.

Argipressin Tannate [M0001692]

Armadillo Domain Proteins [M0165209]
A family of proteins that contain several 42-amino acid repeat domains and are homologous to the Drosophila armadillo protein. They bind to other proteins through their armadillo domains and play a variety of roles in the CELL including SIGNAL TRANSDUCTION, regulation of DESMOSOME assembly, and CELL ADHESION.

Aromatase [M0001707]
An enzyme that catalyzes the desaturation (aromatization) of the ring A of C19 androgens and converts them to C18 estrogens. In this process, the 19-methyl is removed. This enzyme is membrane-bound, located in the endoplasmic reticulum of estrogen-producing cells of ovaries, placenta, testes, adipose, and brain tissues. Aromatase is encoded by the CYP19 gene, and functions in complex with NADPH-FERRIHEMOPROTEIN REDUCTASE in the cytochrome P-450 system.

Aromatic-L-Amino-Acid Decarboxylases [M0001711]
An enzyme group with broad specificity. The enzymes decarboxylate a range of aromatic amino acids including dihydroxyphenylalanine (DOPA DECARBOXYLASE), tryptophan, and hydroxytryptophan. EC 4.1.1.28.

Arrestin [M0028858]
A 48-Kd protein of the outer segment of the retinal rods and a component of the phototransduction cascade. Arrestin quenches G-protein activation by binding to phosphorylated photolyzed rhodopsin. Arrestin causes experimental autoimmune uveitis when injected into laboratory animals.

Arrestins [M0028856]
Regulatory proteins that down-regulate phosphorylated G-protein membrane receptors, including rod and cone photoreceptors and adrenergic receptors.

Arsenate Reductase (Azurin) [M0493906]
A arsenate reductase that can use azurin as a donor-acceptor. It can use a c-type cytochrome or O(2) as donor-acceptor.

Arsenate Reductase (Donor) [M0493907]
An EC classified subtype with unspecified electron acceptor-donor. Reduced glutaredoxin cannot serve as a reductant for this enzyme. Formerly classified as EC 1.97.1.6

Arsenate Reductase (Glutaredoxin) [M0493905]

Arsenate Reductases [M0461594]
Oxidoreductases that specifically reduce arsenate ion to arsenite ion. Reduction of arsenate is a critical step for its biotransformation into a form that can be transported by ARSENITE TRANSPORTING ATPASES or complexed by specific sulfhydryl-containing proteins for the purpose of detoxification (METABOLIC DETOXIFICATION, DRUG).

Arsenite Transporting ATPases [M0172296]
Efflux pumps that use the energy of ATP hydrolysis to pump arsenite across a membrane. They are primarily found in prokaryotic organisms, where they play a role in protection against excess intracellular levels of arsenite ions.

Arvin [M0001094]

Arvin IRC-50 [M0001093]

Aryl Hydrocarbon Hydroxylases [M0001774]
A large group of cytochrome P-450 (heme-thiolate) monooxygenases that complex with NAD(P)H-FLAVIN OXIDOREDUCTASE in numerous mixed-function oxidations of aromatic compounds. They catalyze hydroxylation of a broad spectrum of substrates and are important in the metabolism of steroids, drugs, and toxins such as PHENOBARBITAL, carcinogens, and insecticides.

Aryl Hydrocarbon Receptor Nuclear Translocator [M0188295]
Aryl hydrocarbon receptor nuclear translocator is a basic HELIX-LOOP-HELIX MOTIF containing protein that forms a complex with DIOXIN RECEPTOR. The complex binds xenobiotic regulatory elements and activates transcription of a variety of genes including UDP GLUCURONOSYLTRANSFERASE. AhR nuclear translocator is also a subunit of HYPOXIA-INDUCIBLE FACTOR 1.

Arylalkylamine N-Acetyltransferase [M0144812]
An acetyltransferase with specificity towards the amine group of aromatic alkylamines (arylalkylamines) such as SEROTONIN. This enzyme is also referred to as serotonin acetylase despite the fact that serotonin acetylation can also occur through the action of broad specificity acetyltransferases such as ARYLAMINE N-ACETYLTRANSFERASE.

Arylamine N-Acetyltransferase [M0001776]
An enzyme that catalyzes the transfer of acetyl groups from ACETYL-COA to arylamines. It can also catalyze acetyl transfer between arylamines without COENZYME A and has a wide specificity for aromatic amines, including SEROTONIN. However, arylamine N-acetyltransferase should not be confused with the enzyme ARYLALKYLAMINE N-ACETYLTRANSFERASE which is also referred to as SEROTONIN ACETYLTRANSFERASE.

Aryldialkylphosphatase [M0080022]
An enzyme which catalyzes the hydrolysis of an aryl-dialkyl phosphate to form dialkyl phosphate and an aryl alcohol. It can hydrolyze a broad spectrum of organophosphate substrates and a number of aromatic carboxylic acid esters. It may also mediate an enzymatic protection of LOW DENSITY LIPOPROTEINS against oxidative modification and the consequent series of events leading to ATHEROMA formation. The enzyme was previously regarded to be identical with Arylesterase (EC 3.1.1.2).

Arylformamidase [M0008755]
An enzyme that catalyzes the conversion of N-formyl-L-kynurenine and water to formate and L-kynurenine. It also acts on other aromatic formylamines. (Enzyme Nomenclature, 1992) EC 3.5.1.9.

Arylsulfatase B1 [M0029763]

Arylsulfatase B2 [M0029764]

Arylsulfatases [M0001780]
Enzymes that catalyze the hydrolysis of a phenol sulfate to yield a phenol and sulfate. Arylsulfatase A, B, and C have been separated. A deficiency of arylsulfatases is one of the causes of metachromatic leukodystrophy (LEUKODYSTROPHY, METACHROMATIC). EC 3.1.6.1.

Arylsulfotransferase [M0023420]
A sulfotransferase that catalyzes the sulfation of a phenol in the presence of 3'-phosphoadenylylsulfate as sulfate donor to yield an aryl sulfate and adenosine 3',5'-bisphosphate. A number of aromatic compounds can act as acceptors; however, organic hydroxylamines are not substrates. Sulfate conjugation by this enzyme is a major pathway for the biotransformation of phenolic and catechol drugs as well as neurotransmitters. EC 2.8.2.1.

Aryltransferases [M0029523]

Asacol [M0029389]

Asacolon [M0474818]

Ascolitin [M0474817]

Ascorbate Oxidase [M0001796]
An enzyme that converts ascorbic acid to dehydroascorbic acid. EC 1.10.3.3.

Asialoglycoprotein Receptor [M0085799]
A C-type lectin that is a cell surface receptor for ASIALOGLYCOPROTEINS. It is found primarily in the LIVER where it mediates the endocytosis of serum glycoproteins.

Asialoglycoproteins [M0001810]
Endogenous glycoproteins from which SIALIC ACID has been removed by the action of sialidases. They bind tightly to the ASIALOGLYCOPROTEIN RECEPTOR which is located on hepatocyte plasma membranes. After internalization by adsorptive ENDOCYTOSIS they are delivered to LYSOSOMES for degradation. Therefore receptor-mediated clearance of asialoglycoproteins is an important aspect of the turnover of plasma glycoproteins. They are elevated in serum of patients with HEPATIC CIRRHOSIS or HEPATITIS.

Asparaginase [M0001815]
A hydrolase enzyme that converts L-asparagine and water to L-aspartate and NH3. EC 3.5.1.1.

Asparaginase medac [M0434509]

Asparagine [M0001818]
A non-essential amino acid that is involved in the metabolic control of cell functions in nerve and brain tissue. It is biosynthesized from ASPARTIC ACID and AMMONIA by asparagine synthetase. (From Concise Encyclopedia Biochemistry and Molecular Biology, 3rd ed)

Asparagine Synthetase B [M0001820]

Aspartame [M0001821]
Flavoring agent sweeter than sugar, metabolized as PHENYLALANINE and ASPARTIC ACID.

Aspartate [M0001841]

Aspartate Aminotransferase, Cytoplasmic [M0370471]
An aspartate aminotransferase found in the CYTOPLASM.

Aspartate Aminotransferase, Mitochondrial [M0370470]
An aspartate aminotransferase found in MITOCHONDRIA.

Aspartate Aminotransferases [M0001823]
Enzymes of the transferase class that catalyze the conversion of L-aspartate and 2-ketoglutarate to oxaloacetate and L-glutamate. EC 2.6.1.1.

Aspartate Ammonia-Lyase [M0001826]
An enzyme that catalyzes the conversion of aspartic acid to ammonia and fumaric acid in plants and some microorganisms. EC 4.3.1.1.

Aspartate Carbamoyltransferase [M0001827]
An enzyme that catalyzes the conversion of carbamoyl phosphate and L-aspartate to yield orthophosphate and N-carbamoyl-L-aspartate. (From Enzyme Nomenclature, 1992) EC 2.1.3.2.

Aspartate Kinase [M0001830]
An enzyme that catalyzes the formation of beta-aspartyl phosphate from aspartic acid and ATP. Threonine serves as an allosteric regulator of this enzyme to control the biosynthetic pathway from aspartic acid to threonine. EC 2.7.2.4.

Aspartate Kinase I [M0001831]

Aspartate Kinase II [M0001832]

Aspartate Kinase III [M0001833]

Aspartate Magnesium Hydrochloride [M0001835]

Aspartate-Ammonia Ligase [M0001819]
An enzyme that catalyzes the formation of asparagine from ammonia and aspartic acid, in the presence of ATP. EC 6.3.1.1.

Aspartate-Semialdehyde Dehydrogenase [M0001834]
An enzyme that catalyzes the conversion of L-aspartate 4-semialdehyde, orthophosphate, and NADP+ to yield L-4-aspartyl phosphate and NADPH. EC 1.2.1.11.

Aspartate-tRNA Ligase [M0001848]
An enzyme that activates aspartic acid with its specific transfer RNA. EC 6.1.1.12.

Aspartic Acid [M0001836]
One of the non-essential amino acids commonly occurring in the L-form. It is found in animals and plants, especially in sugar cane and sugar beets. It may be a neurotransmitter.

Aspartic Acid, Ammonium Salt [M0330809]

Aspartic Acid, Calcium Salt [M0330805]

Aspartic Acid, Dipotassium Salt [M0330803]

Aspartic Acid, Disodium Salt [M0330812]

Aspartic Acid, Hydrobromide [M0330807]

Aspartic Acid, Hydrochloride [M0330802]

Aspartic Acid, Magnesium (1:1) Salt, Hydrochloride, Trihydrate [M0330814]

Aspartic Acid, Magnesium (2:1) Salt [M0330804]

Aspartic Acid, Magnesium-Potassium (2:1:2) Salt [M0330796]

Aspartic Acid, Monopotassium Salt [M0330798]

Aspartic Acid, Monosodium Salt [M0330810]

Aspartic Acid, Potassium Salt [M0330800]

Aspartic Acid, Sodium Salt [M0330801]

Aspartic Endopeptidases [M0024885]
A sub-subclass of ENDOPEPTIDASES that depend on an ASPARTIC ACID residue for their activity. EC 3.4.23.

Aspartokinase Homoserine Dehydrogenase [M0001845]
An enzyme complex consisting of aspartokinase, EC 2.7.2.4, and homoserine dehydrogenase, EC 1.1.1.3. The complex has been isolated from E. coli and consists of four identical subunits with a molecular weight of 85,000. The enzyme complex is involved in the biosynthesis of amino acids of the aspartate family.

Aspartokinase I Homoserine Dehydrogenase I [M0001846]

Aspartokinase II Homoserine Dehydrogenase II [M0001847]

Aspartylglucosylaminase [M0001849]
An enzyme that catalyzes the conversion of N(4)-(beta-N-acetyl-D-glucosaminyl)-L-asparagine and water to N-acetyl-beta-D-glucosaminylamine and L-aspartate. It acts only on asparagine oligosaccharides containing one amino acid, i.e. the asparagine has free alpha-amino and alpha-carboxyl groups. (From Enzyme Nomenclature, 1992) EC 3.5.1.26.

Aspergillus Nuclease S1 [M0024101]
An enzyme that catalyzes endonucleolytic cleavage to 5-phosphomononucleotides and 5-phosphooligonucleotide end-products. It has a preference for single-stranded substrates but is active with either ribo- or deoxyribonucleic acids. (From Enzyme Nomenclature, 1992) EC 3.1.30.1.

Astra 2045 [M0373883]

AT III [M0434011]

Atenativ [M0434012]

ATGAM [M0001466]

ATP Citrate (pro-S)-Lyase [M0001918]
An enzyme that, in the presence of ATP and COENZYME A, catalyzes the cleavage of citrate to yield acetyl CoA, oxaloacetate, ADP, and ORTHOPHOSPHATE. This reaction represents an important step in fatty acid biosynthesis. This enzyme was formerly listed as EC 4.1.3.8.

ATP Phosphoribosyltransferase [M0001919]
An enzyme that catalyzes the first step of the pathway for histidine biosynthesis in Salmonella typhimurium. ATP reacts reversibly with 5-phosphoribosyl-1-pyrophosphate to yield N-1-(5'-phosphoribosyl)-ATP and pyrophosphate. EC 2.4.2.17.

ATP Synthetase Complexes [M0072576]
Multisubunit enzyme complexes that synthesize ADENOSINE TRIPHOSPHATE from energy sources such as ions traveling through channels.

ATP-Binding Cassette Transporters [M0027776]
A family of MEMBRANE TRANSPORT PROTEINS that require ATP hydrolysis for the transport of substrates across membranes. The protein family derives its name from the ATP-binding domain found on the protein.

ATP-Dependent DNA Helicases [M0494239]

ATP-Dependent Endoprotease [M0095032]

ATP-Dependent Proteases [M0095033]
Proteases that contain proteolytic core domains and ATPase-containing regulatory domains. They are usually comprised of large multi-subunit assemblies. The domains can occur within a single peptide chain or on distinct subunits.

ATP-Mg(II)-Dependent Protein Phosphatase [M0016690]

Atrial Myosins [M0371732]
Myosin type II isoforms specifically found in the atrial muscle of the heart.

Atrial Natriuretic Factor [M0014517]
A potent natriuretic and vasodilatory peptide or mixture of different-sized low molecular weight PEPTIDES derived from a common precursor and secreted mainly by the HEART ATRIUM. All these peptides share a sequence of about 20 AMINO ACIDS.

Atrial Natriuretic Factor Precursors [M0447922]
Polypeptides of about 150 amino acids that serve as precursors to prohormone of ATRIAL NATRIURETIC FACTOR, a 126-amino acid polypeptide or ANP (1-126).

Atrofen [M0454554]

Autocrine Motility Factor [M0025255]
A protein cytokine secreted by tumor cells. It elicits increases in cell motility and phosphoinositide metabolism in the secreting cell via a pertussis toxin-sensitive G-protein signal transduction pathway. It is closely related to PHOSPHOHEXOSE ISOMERASE; NEUROLEUKIN; and maturation factor.

Autolysin [M0014391]

Autoreceptors [M0026715]
Transmitter receptors on or near presynaptic terminals (or varicosities) which are sensitive to the transmitter(s) released by the terminal itself. Receptors for the hormones released by hormone-releasing cells are also included.

Auxilins [M0146891]
A family of proteins that play a role as cofactors in the process of CLATHRIN recycling in cells.

Avazyme [M0478342]

Avelizin [M0020583]

Avian Proteins [M0386063]
Proteins obtained from species of BIRDS.

Avicelase [M0445481]

Avicelase II [M0445559]

Avicon [M0369414]

Avidin [M0002040]
A specific protein in egg albumin that interacts with BIOTIN to render it unavailable to mammals, thereby producing biotin deficiency.

Avitene [M0369415]

Awelysin [M0020584]

Axon-Associated Adhesion Molecules [M0024225]

AY-25650 [M0337461]

Azaserine [M0002063]
Antibiotic substance produced by various Streptomyces species. It is an inhibitor of enzymatic activities that involve glutamine and is used as an antineoplastic and immunosuppressive agent.

Azetidinecarboxylic Acid [M0002071]
A proline analog that acts as a stoichiometric replacement of proline. It causes the production of abnormal proteins with impaired biological activity.

Azubronchin [M0445744]

Azurin [M0002095]
A bacterial protein from Pseudomonas, Bordetella, or Alcaligenes which operates as an electron transfer unit associated with the cytochrome chain. The protein has a molecular weight of approximately 16,000, contains a single copper atom, is intensively blue, and has a fluorescence emission band centered at 308nm.

B-Cell Activating Factor [M0305108]
A tumor necrosis factor superfamily member that plays a role in the regulation of B-LYMPHOCYTE survival. It occurs as a membrane-bound protein that is cleaved to release an biologically active soluble form with specificity to TRANSMEMBRANE ACTIVATOR AND CAML INTERACTOR PROTEIN; B-CELL ACTIVATION FACTOR RECEPTOR; and B-CELL MATURATION ANTIGEN.

B-Cell Activation Factor Receptor [M0492195]
A member of the tumor necrosis factor receptor superfamily that specifically binds B-CELL ACTIVATING FACTOR. It is found on B-LYMPHOCYTES and plays a role in maturation and survival of B-cells. Signaling by the activated receptor occurs through its association with TNF RECEPTOR-ASSOCIATED FACTORS.

B-Cell Leukemia 2 Family Proteins [M0480025]

B-Cell Maturation Antigen [M0492351]
A member of the tumor necrosis factor receptor superfamily found on mature B-LYMPHOCYTES. It has specificity for B CELL ACTIVATING FACTOR and TUMOR NECROSIS FACTOR LIGAND SUPERFAMILY MEMBER 13. Signaling of the receptor occurs through its association with TNF RECEPTOR-ASSOCIATED FACTORS.

B-Cell-Specific Activator Protein [M0200645]
A transcription factor that is essential for CELL DIFFERENTIATION of B-LYMPHOCYTES. It functions both as a transcriptional activator and repressor to mediate B-cell commitment.

B220 Antigens [M0026537]

Ba-34,647 [M0351459]

Baci-IM [M0454530]

Baciguent [M0454531]

Bacillus amyloliquefaciens Serine Protease [M0020687]

Bacillus subtilis Alkaline Proteinase [M0020688]

Bacitin [M0454532]

Bacitracin [M0002112]
A complex of cyclic peptide antibiotics produced by the Tracy-I strain of Bacillus subtilis. The commercial preparation is a mixture of at least nine bacitracins with bacitracin A as the major constituent. It is used topically to treat open infections such as infected eczema and infected dermal ulcers. (From Goodman and Gilman, The Pharmacological Basis of Therapeutics, 8th ed, p1140)

Bacitracin Zinc Complex [M0330826]

Bacitracine Martinet [M0454533]

Baclofen [M0002117]
A GAMMA-AMINOBUTYRIC ACID derivative that is a specific agonist at GABA-B receptors (RECEPTORS, GABA-B). It is used in the treatment of spasticity, especially that due to spinal cord damage. Its therapeutic effects result from actions at spinal and supraspinal sites, generally the reduction of excitatory transmission.

Baclofen AWD [M0454556]

Baclof�ne-Irex [M0454553]

Baclospas [M0454552]

Bacterial Capsules [M0025399]
An envelope of loose gel surrounding a bacterial cell which is associated with the virulence of pathogenic bacteria. Some capsules have a well-defined border, whereas others form a slime layer that trails off into the medium. Most capsules consist of relatively simple polysaccharides but there are some bacteria whose capsules are made of polypeptides.

Bacterial Electron Transport Chain Complex Proteins [M0449188]

Bacterial Electron Transport Complex I [M0449186]

Bacterial Electron Transport Complex II [M0449190]

Bacterial Electron Transport Complex III [M0449354]

Bacterial Electron Transport Complex IV [M0449192]

Bacterial Elongation Factor Tu [M0016218]
RN should be EC 3.6.1.-

Bacterial Outer Membrane Proteins [M0002127]
Proteins isolated from the outer membrane of Gram-negative bacteria.

Bacterial Proteins [M0002130]
Proteins found in any species of bacterium.

Bacterial Proton-Translocating ATPases [M0374012]
Membrane-bound proton-translocating ATPases that serve two important physiological functions in bacteria. One function is to generate ADENOSINE TRIPHOSPHATE by utilizing the energy provided by an electrochemical gradient of protons across the cellular membrane. A second function is to counteract a loss of the transmembrane ion gradient by pumping protons at the expense of adenosine triphosphate hydrolysis.

Bacterial Rhodopsins [M0375173]
Although similar in name and structure to BACTERIORHODOPSINS from HALOBACTERIUM HALOBIUM, this is a distinct class of proteins found in certain species of PROTEOBACTERIA.

Bacterial Transferrin Receptor Complex [M0404226]
A complex of proteins that forms a receptor for TRANSFERRIN in BACTERIA. Many pathogenic bacteria utilize the transferrin-binding complex to acquire their supply of iron from serum.

Bacteriocins [M0002136]
Substances elaborated by specific strains of bacteria that are lethal against other strains of the same or related species. They are protein or lipopolysaccharide-protein complexes used in taxonomy studies of bacteria.

Bacteriophage T7 Gene 4 Protein [M0369436]

Bacteriorhodopsins [M0002142]
Rhodopsins found in the PURPLE MEMBRANE of halophilic archaea such as HALOBACTERIUM HALOBIUM. Bacteriorhodopsins function as an energy transducers, converting light energy into electrochemical energy via PROTON PUMPS.

BAE-PAI [M0024268]

Banded Hedgehog Protein [M0496703]

Basic Helix-Loop-Helix Leucine Zipper Transcription Factors [M0481794]
A family of transcription factors that contain regions rich in basic residues, LEUCINE ZIPPER domains, and HELIX-LOOP-HELIX MOTIFS.

Basic Helix-Loop-Helix Transcription Factors [M0481850]
A family of DNA-binding transcription factors that contain a basic HELIX-LOOP-HELIX MOTIF.

Basic Isoferritin [M0041686]

Basic Protein, Encephalitogenic [M0007365]

Basic-Leucine Zipper Transcription Factors [M0478896]
A large superfamily of transcription factors that contain a region rich in BASIC AMINO ACID residues followed by a LEUCINE ZIPPER domain.

Batroxobin [M0018820]
A proteolytic enzyme obtained from the venom of fer-de-lance (Bothrops atrox). It is used as a plasma clotting agent for fibrinogen and for the detection of fibrinogen degradation products. The presence of heparin does not interfere with the clotting test. Hemocoagulase is a mixture containing batroxobin and factor X activator. EC 3.4.21.-.

BB-10010 [M0028877]

bcl-2 Homologous Antagonist-Killer Protein [M0245556]
A multi-domain mitochondrial membrane protein and member of the bcl-2 Protein family. Bak protein interacts with TUMOR SUPPRESSOR PROTEIN P53 and promotes APOPTOSIS.

bcl-2-Associated X Protein [M0220651]
A member of the Bcl-2 protein family and homologous partner of C-BCL-2 PROTO-ONCOGENE PROTEIN. It regulates the release of CYTOCHROME C and APOPTOSIS INDUCING FACTOR from the MITOCHONDRIA. Several isoforms of BCL2-associated X protein occur due to ALTERNATIVE SPLICING of the mRNA for this protein.

bcl-Associated Death Protein [M0242303]
A pro-apoptotic protein and member of the Bcl-2 protein family that is regulated by PHOSPHORYLATION. Unphosphorylated Bad protein inhibits the activity of BCL-XL PROTEIN.

bcl-X Protein [M0220648]
A member of the bcl-2 protein family that plays a role in the regulation of APOPTOSIS. Two major isoforms of the protein exist due to ALTERNATIVE SPLICING of the BCL2L1 mRNA and are referred to as Bcl-XS and Bcl-XL.

bcl-Xalpha Protein [M0478996]

bcl-Xbeta Protein [M0480110]

bcl-XL Protein [M0220645]
Bcl-XL is an anti-apoptotic protein that is the long isoform of Bcl-X protein. Bcl-XL localizes to the outer mitochondrial membrane and is overexpressed in most human NEOPLASMS. It has also been implicated in ISCHEMIC HEART DISEASE.

bcl-XS Protein [M0220646]
A pro-apoptotic protein that is the short isoform of Bcl-X protein. Bcl-XS lacks the BH1 and BH2 domains of BCL-XL PROTEIN and it inhibits the ANTI-APOPTOTIC PROTEINS of the bcl-2 protein family.

bcl2-Associated X Protein Isoform alpha [M0479012]

bcl2-Associated X Protein Isoform beta [M0480106]

bcl2-Associated X Protein Isoform delta [M0479011]

bcl2-Associated X Protein Isoform omega [M0410933]

bcl2-Associated X Protein Isoform sigma [M0479009]

Beano [M0387208]
t126

Bence Jones Protein [M0002304]
An abnormal protein with unusual thermosolubility characteristics that is found in the urine of patients with MULTIPLE MYELOMA.

Bence Jones Protein Den [M0002305]

Bence Jones Protein SUT [M0002306]

Benzaldehyde Dehydrogenase (NADP+) [M0072592]
An NADP+ dependent enzyme that catalyzes the oxidation of BENZALDEHYDE to BENZOIC ACID. It also plays a role in the degradation of TOLUENE and XYLENE.

Benzoate 4-Monooxygenase [M0072598]
An enzyme that catalyzes the oxidation of BENZOATE to 4-HYDROXYBENZOATE. It requires IRON and tetrahydropteridine.

Benzodiazepine Receptor [M0018591]

Benzopyrene Hydroxylase [M0002368]
A drug-metabolizing, cytochrome P-448 (P-450) enzyme which catalyzes the hydroxylation of benzopyrene to 3-hydroxybenzopyrene in the presence of reduced flavoprotein and molecular oxygen. Also acts on certain anthracene derivatives. An aspect of EC 1.14.14.1.

Benzoylarginine Nitroanilide [M0002377]
A chromogenic substrate that permits direct measurement of peptide hydrolase activity, e.g., papain and trypsin, by colorimetry. The substrate liberates p-nitroaniline as a chromogenic product.

Benzoylarginine Nitroanilide Monohydrochloride [M0330842]

Benzoylarginine Nitroanilide, (R)-Isomer [M0330838]

Benzoylarginine Nitroanilide, (S)-Isomer [M0330839]

Benzoylarginine Nitroanilide, Monosodium Salt, Monohydrochloride [M0330840]

Benzoylarginine-2-Naphthylamide [M0002379]
An enzyme substrate which permits the measurement of peptide hydrolase activity, e.g. trypsin and thrombin. The enzymes liberate 2-naphthylamine, which is measured by colorimetric procedures.

Benzylamine Oxidase [M0002389]
An aspect of monoamine oxidase, EC 1.4.3.4. Catalyzes the oxidation of benzylamine to form benzaldehyde, ammonia and hydrogen peroxide.

Benzylpenicillin Acylase [M0016128]

Benzylpenicillinase [M0016144]

Beriplast [M0373275]

Berlthyrox [M0463497]

beta 2-Glycoprotein I [M0071001]
A 44-kDa highly glycosylated plasma protein that binds phospholipids including CARDIOLIPIN; APOLIPOPROTEIN E RECEPTOR; membrane phospholipids, and other anionic phospholipid-containing moieties. It plays a role in coagulation and apoptotic processes. Formerly known as apolipoprotein H, it is an autoantigen in patients with ANTIPHOSPHOLIPID ANTIBODIES.

beta 2-Microglobulin [M0002412]
An 11-kDa protein associated with the outer membrane of many cells including lymphocytes. It is the small subunit of the MHC class I molecule. Association with beta 2-microglobulin is generally required for the transport of class I heavy chains from the endoplasmic reticulum to the cell surface. Beta 2-microglobulin is present in small amounts in serum, csf, and urine of normal people, and to a much greater degree in the urine and plasma of patients with tubular proteinemia, renal failure, or kidney transplants.

beta 2-Transferrin [M0021803]

beta Catenin [M0195076]
A multi-functional catenin that participates in CELL ADHESION and nuclear signaling. Beta catenin binds CADHERINS and helps link their cytoplasmic tails to the ACTIN in the CYTOSKELETON via ALPHA CATENIN. It also serves as a transcriptional co-activator and downstream component of WNT PROTEIN-mediated SIGNAL TRANSDUCTION PATHWAYS.

beta Karyopherins [M0249033]
Nucleocytoplasmic transport molecules that bind to ALPHA KARYOPHERINS in the CYTOSOL and are involved in transport of molecules through the NUCLEAR PORE COMPLEX. Once inside the CELL NUCLEUS beta karyopherins interact with RAN GTP-BINDING PROTEIN and dissociate from alpha karyopherins. Beta karyopherins bound to RAN GTP-BINDING PROTEIN are then re-transported to the cytoplasm where hydrolysis of the GTP of RAN GTP-BINDING PROTEIN causes release of karyopherin beta.

beta Keto-Acyl Carrier Protein Synthase I [M0023224]

beta Keto-Acyl Carrier Protein Synthase II [M0023225]

beta Lactamase III [M0016145]

beta Lactamase RP4 [M0016146]

Beta(1)CA Globulin [M0002407]

beta,gamma-Thrombin [M0021421]

beta-1 Globin [M0009283]

beta-1 Interferon [M0025714]

Beta-1,3-Glucanase Type II [M0408492]

beta-2 Thromboglobulin [M0002427]

beta-Actin [M0000299]

beta-Actinin [M0000276]

beta-Adrenergic Receptor Kinase [M0148824]
A cyclic-AMP protein kinase that mediates agonist-dependent PHOSPHORYLATION and desensitization of G-PROTEIN-COUPLED RECEPTORS.

beta-Alanine [M0023212]
An amino acid formed in vivo by the degradation of dihydrouracil and carnosine. Since neuronal uptake and neuronal receptor sensitivity to beta-alanine have been demonstrated, the compound may be a false transmitter replacing GAMMA-AMINOBUTYRIC ACID. A rare genetic disorder, hyper-beta-alaninemia, has been reported.

beta-Alanine Hydrochloride [M0329505]

beta-Alanine, Calcium Salt (2:1) [M0329503]

beta-Alanine, Monopotassium Salt [M0329504]

beta-Alanine, Monosodium Salt [M0329502]

beta-Alanine-Pyruvate Transaminase [M0079278]
A PYRIDOXAL PHOSPHATE containing enzyme that catalyzes the transfer of an amino group from L-ALANINE to 3-oxopropanoate to generate PYRUVATE and BETA-ALANINE.

beta-Amylase [M0002413]
An enzyme that catalyzes the hydrolysis of 1,4-alpha-glycosidic linkages in starch, glycogen, and related polysaccharides and oligosaccharides so as to remove successive beta-maltose units from the non-reducing ends of the chains. EC 3.2.1.2.

beta-Atrial Natriuretic Peptide [M0014515]
An antiparallel dimer of alpha-ANP with the chains linked by 7-23' and 7'-23 disulfide bonds.

beta-Carotene 15,15'-Monooxygenase [M0072771]
A monooxygenase that catalyzes the conversion of BETA-CAROTENE into two molecules of RETINAL. It was formerly characterized as EC 1.13.11.21 and EC 1.18.3.1.

beta-Caseins [M0003588]

beta-Caveolin [M0209021]

beta-CGRP [M0024125]

beta-Crystallin A Chain [M0415412]
The acidic subunit of beta-crystallins.

beta-Crystallin B Chain [M0415413]
The basic subunit of beta-crystallins.

beta-Crystallins [M0005390]
A class of crystallins that provides refractive power and translucency to the lens (LENS, CRYSTALLINE) in VERTEBRATES. Beta-crystallins are similar in structure to GAMMA-CRYSTALLINS in that they both contain Greek key motifs. Beta-crystallins exist as oligomers formed from acidic (BETA-CRYSTALLIN A CHAIN) and basic (BETA-CRYSTALLIN B CHAIN) subunits.

beta-D-Gal(1-3)D-GalNAc Specific Lectins [M0067934]

beta-Defensins [M0360490]
DEFENSINS found mainly in epithelial cells.

beta-Dystroglycan [M0454542]

beta-Endorphin [M0002414]
A 31-amino acid peptide that is the C-terminal fragment of BETA-LIPOTROPIN. It acts on OPIOID RECEPTORS and is an analgesic. Its first four amino acids at the N-terminal are identical to the tetrapeptide sequence of METHIONINE ENKEPHALIN and LEUCINE ENKEPHALIN.

beta-Endorphin Receptor [M0018576]

beta-Enolase [M0016707]

beta-Fructofuranosidase [M0071827]
A glycoside hydrolase found primarily in PLANTS and YEASTS. It has specificity for beta-D-fructofuranosides such as SUCROSE.

beta-Galactosidase [M0002418]
A group of enzymes that catalyzes the hydrolysis of terminal, non-reducing beta-D-galactose residues in beta-galactosides. Deficiency of beta-Galactosidase A1 may cause GANGLIOSIDOSIS, GM1.

beta-Galactosidase A1 [M0002415]

beta-Galactosidase A2 [M0002416]

beta-Galactosidase A3 [M0002417]

beta-Globin [M0009284]

Beta-Globulins [M0002406]
Serum proteins with an electrophoretic mobility that falls between ALPHA-GLOBULINS and GAMMA-GLOBULINS.

beta-Glucosidase [M0002419]
An exocellulase with specificity for a variety of beta-D-glycoside substrates. It catalyzes the hydrolysis of terminal non-reducing residues in beta-D-glucosides with release of GLUCOSE.

beta-Glucosidases [M0445577]

beta-Hydroxyacyl CoA Dehydrogenase [M0023216]

beta-Kallikrein [M0011895]

beta-Kallikrein B [M0011896]

beta-Keratins [M0011944]
Keratins that form into a beta-pleated sheet structure. They are principle constituents of the corneous material of the carapace and plastron of turtles, the epidermis of snakes and the feathers of birds.

beta-Keto-Reductase [M0023217]

beta-Lactamase I [M0016147]

beta-Lactamases [M0002421]
Enzymes found in many bacteria which catalyze the hydrolysis of the amide bond in the beta-lactam ring. Well known antibiotics destroyed by these enzymes are penicillins and cephalosporins.

beta-Lactoglobulin [M0012166]

beta-Lactoglobulin A [M0012167]

beta-Lactoglobulin B [M0012168]

beta-Lactoglobulin C [M0012169]

beta-Lactoglobulin E [M0012170]

beta-Lactoglobulin F [M0012171]

beta-Lactoglobulin G [M0012172]

beta-Lactoglobulin I [M0012173]

beta-Lipotropin [M0012607]
A 90-amino acid peptide derived from post-translational processing of pro-opiomelanocortin (POMC) in the PITUITARY and the HYPOTHALAMUS. It is the C-terminal fragment of POMC with lipid-mobilizing activities, such as LIPOLYSIS and steroidogenesis. Depending on the species and the tissue sites, beta-LPH may be further processed to yield active peptides including GAMMA-LIPOTROPIN; BETA-MSH; and ENDORPHINS.

beta-Mannosidase [M0086105]
An enzyme that catalyzes the hydrolysis of terminal, non-reducing beta-D-mannose residues in beta-D-mannosides. The enzyme plays a role in the lysosomal degradation of the N-glycosylprotein glycans. Defects in the lysosomal form of the enzyme in humans result in a buildup of mannoside intermediate metabolites and the disease BETA-MANNOSIDOSIS.

beta-MSH [M0328127]
An 18-amino acid peptide that is the C-terminal fragment of gamma-lipotropin which is the N-terminal fragment of BETA-LIPOTROPIN. Beta-MSH is shown to regulate skin pigmentation, steroid production, and feeding.

beta-N-Acetyl-Galactosaminidase [M0070475]
A hexosiminidase that specifically hydrolyzes terminal non-reducing N-acetyl-D-galactosamine residues in N-acetyl-beta-D-galactosaminides.

beta-N-Acetylglucosaminide beta 1-4 Galactosyltransferase [M0009492]

beta-N-Acetylglucosaminylglycopeptide beta-1,4-Galactosyltransferase [M0009490]
An enzyme that catalyzes the transfer of galactose from UDP-galactose to a specific glycoprotein receptor, 2-acetamido-2-deoxy-D-glucosyl-glycopeptide, during glycopeptide synthesis. EC 2.4.1.38.

beta-N-Acetylhexosaminidase [M0002423]
An enzyme hydrolyzing terminal non-reducing N-acetyl-D-hexosamine residues in N-acetyl-beta-D-hexosaminides. It acts on GLUCOSIDES; GALACTOSIDES; and several OLIGOSACCHARIDES. Hexosaminidase A cleaves GM2, GA2, globosides, and hexosamine oligosaccharides. Hexosaminidase B cleaves all the above substrates except GM2. Deficiency of Hexosaminidase A causes TAY-SACHS DISEASE, while deficiency of both A and B isozymes causes SANDHOFF DISEASE. The enzyme has also been used as a tumor marker to distinguish between malignant and benign disease.

beta-Sarcoglycan [M0454543]

beta-Secretase [M0470165]

beta-SNAP [M0202545]

beta-Spectrin [M0020227]

Beta-Stathmin [M0166754]

beta-Synuclein [M0159751]
A synuclein that is closely related to ALPHA-SYNUCLEIN. It may play a neuroprotective role against some of the toxic effects of aggregated ALPHA-SYNUCLEIN.

beta-Thrombin [M0021422]

beta-Thromboglobulin [M0002428]
A platelet-specific protein which is released when platelets aggregate. Elevated plasma levels have been reported after deep venous thrombosis, pre-eclampsia, myocardial infarction with mural thrombosis, and myeloproliferative disorders. Measurement of beta-thromboglobulin in biological fluids by radioimmunoassay is used for the diagnosis and assessment of progress of thromboembolic disorders.

beta-Transducin [M0023547]

beta-Transducin Repeat-Containing Proteins [M0219301]
A family of F-box domain proteins that contain sequences that are homologous to the beta subunit of transducin (BETA-TRANSDUCIN). They play an important role in the protein degradation pathway by becoming components of SKP CULLIN F-BOX PROTEIN LIGASES, which selectively act on a subset of proteins including beta-catenin and IkappaBbeta.

beta-Tropomyosin [M0022042]

beta-Trypsin [M0022077]

beta-Tryptases [M0210455]

beta-Tubulin [M0022140]

beta-Very-Low-Density Lipoproteins [M0493077]

beta-Vinculin [M0025314]

Betaine-Aldehyde Dehydrogenase [M0072626]
An NAD+ dependent enzyme that catalyzes the oxidation of betain aldehyde to BETAINE.

Betaine-Homocysteine Methyltransferase 2 [M0478732]

Betaine-Homocysteine S-Methyltransferase [M0079869]
A ZINC metalloenzyme that catalyzes the transfer of a methyl group from BETAINE to HOMOCYSTEINE to produce dimethylglycine and METHIONINE, respectively. This enzyme is a member of a family of ZINC-dependent METHYLTRANSFERASES that use THIOLS or selenols as methyl acceptors.

BH3 Interacting Domain Death Agonist Protein [M0267914]
A member of the Bcl-2 protein family that reversibly binds MEMBRANES. It is a pro-apoptotic protein that is activated by caspase cleavage.

Big Endothelin 3 [M0219571]
An alternatively processed form of endothelin-3 that is larger in size.

Bilirubin UDP-Glucuronyltransferase [M0022218]

Binding Protein [M0003561]

Biogonadil [M0009541]

Biological Pumps [M0379231]

Biotinidase [M0111867]
An enzyme which catalyzes the release of BIOTIN from biocytin. In human, defects in the enzyme are the cause of the organic acidemia MULTIPLE CARBOXYLASE DEFICIENCY or BIOTINIDASE DEFICIENCY.

Bis-Penicillamine-Enkephalin [M0117564]

Bisolvon NAC [M0445980]

Bispecific Monoclonal Antibodies [M0027218]

Bisphosphoglycerate Mutase [M0002612]
An enzyme that catalyzes the transfer of phosphate from C-3 of 1,3-diphosphoglycerate to C-2 of 3-phosphoglycerate, forming 2,3-diphosphoglycerate. EC 5.4.2.4.

Blenoxane [M0369271]

BLEO-cell [M0460676]

Bleolem [M0460669]

Bleomicina [M0460670]

Bleomycin [M0002657]
A complex of related glycopeptide antibiotics from Streptomyces verticillus consisting of bleomycin A2 and B2. It inhibits DNA metabolism and is used as an antineoplastic, especially for solid tumors.

Bleomycin A2 [M0002654]

Bleomycin B2 [M0002655]

Bleomycin Sulfate [M0330861]

Bl�omycine Bellon [M0460677]

Bleomycinum Mack [M0460675]

Blood Coagulation Factors [M0002684]
Endogenous substances, usually proteins, that are involved in the blood coagulation process.

Blood Proteins [M0002710]
Proteins that are present in blood serum, including SERUM ALBUMIN; BLOOD COAGULATION FACTORS; and many other types of proteins.

BLV Antibodies [M0023839]

BLV Antigens [M0023846]

Bombesin [M0002763]
A tetradecapeptide originally obtained from the skins of toads Bombina bombina and B. variegata. It is also an endogenous neurotransmitter in many animals including mammals. Bombesin affects vascular and other smooth muscle, gastric secretion, and renal circulation and function.

Bombesin Dihydrochloride [M0330862]

Bone Morphogenetic Protein Receptor, Type IA [M0430790]

Bone Morphogenetic Protein Receptor, Type IB [M0430789]

Bone Morphogenetic Protein Receptors [M0237324]
A family of CELL SURFACE RECEPTORS that bind BONE MORPHOGENETIC PROTEINS. They are PROTEIN-SERINE-THREONINE KINASES that mediate SIGNAL TRANSDUCTION PATHWAYS through SMAD PROTEINS.

Bone Morphogenetic Protein Receptors, Type I [M0235135]
A subtype of bone morphogenetic protein receptors with high affinity for BONE MORPHOGENETIC PROTEINS. They can interact with and undergo PHOSPHORYLATION by BONE MORPHOGENETIC PROTEIN RECEPTORS, TYPE II. They signal primarily through RECEPTOR-REGULATED SMAD PROTEINS.

Bone Morphogenetic Protein Receptors, Type II [M0248475]
A subtype of bone morphogenetic protein receptors with low affinity for BONE MORPHOGENETIC PROTEINS. They are constitutively active PROTEIN-SERINE-THREONINE KINASES that can interact with and phosphorylate TYPE I BONE MORPHOGENETIC PROTEIN RECEPTORS.

Bone Morphogenetic Proteins [M0028976]
Bone-growth regulatory factors that are members of the transforming growth factor-beta superfamily of proteins. They are synthesized as large precursor molecules which are cleaved by proteolytic enzymes. The active form can consist of a dimer of two identical proteins or a heterodimer of two related bone morphogenetic proteins.

Bordetella pertussis Adenylate Cyclase Toxin [M0412693]

Bovine Activator Protein [M0003212]

Bovine Leukemia Virus Glycoprotein gp51 [M0022707]

Bradykinin [M0002864]
A nonapeptide messenger that is enzymatically produced from KALLIDIN in the blood where it is a potent but short-lived agent of arteriolar dilation and increased capillary permeability. Bradykinin is also released from MAST CELLS during asthma attacks, from gut walls as a gastrointestinal vasodilator, from damaged tissues as a pain signal, and may be a neurotransmitter.

Bradykinin Acetate, (9-D-Arg)-Isomer [M0330878]

Bradykinin Diacetate [M0330871]

Bradykinin Hydrochloride [M0330875]

Bradykinin Triacetate [M0330876]

Bradykinin, (1-D-Arg)-Isomer [M0330873]

Bradykinin, (2-D-Pro)-Isomer [M0330867]

Bradykinin, (2-D-Pro-3-D-Pro-7-D-Pro)-Isomer [M0330866]

Bradykinin, (2-D-Pro-7-D-Pro)-Isomer [M0330880]

Bradykinin, (3-D-Pro)-Isomer [M0330864]

Bradykinin, (3-D-Pro-7-D-Pro)-Isomer [M0330879]

Bradykinin, (5-D-Phe)-Isomer [M0330868]

Bradykinin, (5-D-Phe-8-D-Phe)-Isomer [M0330872]

Bradykinin, (6-D-Ser)-Isomer [M0330863]

Bradykinin, (7-D-Pro)-Isomer [M0330870]

Bradykinin, (8-D-Phe)-Isomer [M0330869]

Bradykinin, (9-D-Arg)-Isomer [M0330874]

Brain-Derived Neurotrophic Factor [M0028612]
A member of the nerve growth factor family of trophic factors. In the brain BDNF has a trophic action on retinal, cholinergic, and dopaminergic neurons, and in the peripheral nervous system it acts on both motor and sensory neurons. (From Kendrew, The Encyclopedia of Molecular Biology, 1994)

Bravelle [M0475589]

BRCA1 Protein [M0028758]
The phosphoprotein encoded by the BRCA1 gene (GENE, BRCA1). In normal cells the BRCA1 protein is localized in the nucleus, whereas in the majority of breast cancer cell lines and in malignant pleural effusions from breast cancer patients, it is localized mainly in the cytoplasm. (Science 1995;270(5237):713,789-91)

BRCA2 Protein [M0242709]
A large, nuclear protein, encoded by the BRCA2 gene (GENE, BRCA2). Mutations in this gene predispose humans to breast and ovarian cancer. The BRCA2 protein is an essential component of DNA repair pathways, suppressing the formation of gross chromosomal rearrangements. (from Genes Dev. 2000;14(11):1400-6)

Brevicidin [M0022196]

Brinolase [M0002923]
A fibrinolytic and thrombolytic enzyme from Aspergillus oryzae. EC 3.4.99.-.

BRL-26921 [M0333009]

Bromelain-POS [M0463076]

Bromelains [M0002933]
Protein-digesting and milk-clotting enzymes found in PINEAPPLE fruit juice and stem tissue. Enzymes from the two sources are distinguished as fruit bromelain and stem bromelain. There has been interest in using it for INFLAMMATION and DEBRIDEMENT. This enzyme was formerly listed as EC 3.4.22.4.

Broncho-Fips [M0445984]

Broncholysin [M0000172]

Broncoclar [M0445988]

Bryamycin [M0373342]

BsuF Endonuclease [M0028379]

Buserelin [M0003073]
A potent synthetic agonist of GONADOTROPIN-RELEASING HORMONE with D-serine substitution at residue 6, glycine10 deletion, and other modifications.

Buserelin Acetate [M0330888]

Buthionine Sulfoximine [M0028777]
A synthetic amino acid that depletes glutathione by irreversibly inhibiting gamma-glutamylcysteine synthetase. Inhibition of this enzyme is a critical step in glutathione biosynthesis. It has been shown to inhibit the proliferative response in human T-lymphocytes and inhibit macrophage activation. (J Biol Chem 1995;270(33):1945-7)

Butyrate Response Factor 1 [M0184853]
A ZINC FINGER MOTIF containing immediate early protein that is closely related to TRISTETRAPROLIN. It interacts with and helps destabilize VASCULAR ENDOTHELIAL GROWTH FACTOR mRNA.

Butyryl-CoA Dehydrogenase [M0072682]
A flavoprotein oxidoreductase that has specificity for short-chain fatty acids. It forms a complex with ELECTRON-TRANSFERRING FLAVOPROTEINS and conveys reducing equivalents to UBIQUINONE.

Butyrylcholinesterase [M0003115]
An aspect of cholinesterase (EC 3.1.1.8).

Butyrylthiocholinesterase [M0003114]

BW-180C [M0373907]

C-Peptide [M0003121]
The middle segment of proinsulin that is between the N-terminal B-chain and the C-terminal A-chain. It is a pancreatic peptide of about 31 residues, depending on the species. Upon proteolytic cleavage of proinsulin, equimolar INSULIN and C-peptide are released. C-peptide immunoassay has been used to assess pancreatic beta cell function in diabetic patients with circulating insulin antibodies or exogenous insulin. Half-life of C-peptide is 30 min, almost 8 times that of insulin.

C-Phycocyanin [M0016772]

C-Reactive Protein [M0003122]
A plasma protein that circulates in increased amounts during inflammation and after tissue damage.

CA I Hiroshima-1 [M0370313]
A variant form of carbonic anhydrase I that has asparagine at position 86 replaced by glycine.

Ca(2+) Mg(2+)-ATPase [M0026264]
An enzyme that catalyzes the hydrolysis of ATP and is activated by millimolar concentrations of either Ca(2+) or Mg(2+). Unlike CA(2+)-TRANSPORTING ATPASE it does not require the second divalent cation for its activity, and is not sensitive to orthovanadate. (Prog Biophys Mol Biol 1988;52(1):1). A subgroup of EC 3.6.1.3.

Ca(2+)-Calmodulin Dependent Protein Kinase [M0027001]
A calmodulin-dependent enzyme that catalyzes the phosphorylation of proteins. This enzyme is also sometimes dependent on calcium. A wide range of proteins can act as acceptor, including vimentin, synapsin, glycogen synthase, myosin light chains, and the microtubule-associated proteins. (From Enzyme Nomenclature, 1992, p277)

Ca++ Calmodulin Dependent Cyclic AMP Phosphodiesterase [M0023234]

Cadherins [M0024234]
Calcium-dependent cell adhesion proteins. They are important in the formation of ADHERENS JUNCTIONS between cells. Cadherins are classified by their distinct immunological and tissue specificities, either by letters (E- for epithelial, N- for neural, and P- for placental cadherins) or by numbers (cadherin-12 or N-cadherin 2 for brain-cadherin). Cadherins promote cell adhesion via a homophilic mechanism as in the construction of tissues and of the whole animal body.

Caenorhabditis elegans Proteins [M0385233]
Proteins from the nematode species CAENORHABDITIS ELEGANS. The proteins from this species are the subject of scientific interest in the area of multicellular organism MORPHOGENESIS.

Caerulein [M0003135]
A specific decapeptide obtained from the skin of Hila caerulea, an Australian amphibian. Caerulein is similar in action and composition to CHOLECYSTOKININ. It stimulates gastric, biliary, and pancreatic secretion; and certain smooth muscle. It is used in paralytic ileus and as diagnostic aid in pancreatic malfunction.

Calcineurin [M0029257]
A calcium- and calmodulin-binding protein present in highest concentrations in the central nervous system. Calcineurin is composed of two subunits. A catalytic subunit, calcineurin A, and a regulatory subunit, calcineurin B, with molecular weights of about 60 kDa and 19 kDa, respectively. Calcineurin has been shown to dephosphorylate a number of phosphoproteins including histones, myosin light chain, and the regulatory subunit of cAMP-dependent protein kinase. It is involved in the regulation of signal transduction and is the target of an important class of immunophilin-immunosuppressive drug complexes in T-lymphocytes that act by inhibiting T-cell activation.

Calcineurin A [M0029259]

Calcineurin B [M0029258]

Calcitonin [M0003145]
A peptide hormone that lowers calcium concentration in the blood. In humans, it is released by thyroid cells and acts to decrease the formation and absorptive activity of osteoclasts. Its role in regulating plasma calcium is much greater in children and in certain diseases than in normal adults.

Calcitonin Gene-Related Peptide [M0024126]
Calcitonin gene-related peptide. A 37-amino acid peptide derived from the calcitonin gene. It occurs as a result of alternative processing of mRNA from the calcitonin gene. The neuropeptide is widely distributed in neural tissue of the brain, gut, perivascular nerves, and other tissue. The peptide produces multiple biological effects and has both circulatory and neurotransmitter modes of action. In particular, it is a potent endogenous vasodilator.

Calcitonin Gene-Related Peptide I [M0024127]

Calcitonin Gene-Related Peptide II [M0024128]

Calcium Channels [M0023383]
Voltage-dependent cell membrane glycoproteins selectively permeable to calcium ions. They are categorized as L-, T-, N-, P-, Q-, and R-types based on the activation and inactivation kinetics, ion specificity, and sensitivity to drugs and toxins. The L- and T-types are present throughout the cardiovascular and central nervous systems and the N-, P-, Q-, & R-types are located in neuronal tissue.

Calcium Channels, L-Type [M0328046]
Long-lasting voltage-gated CALCIUM CHANNELS found in both excitable and nonexcitable tissue. They are responsible for normal myocardial and vascular smooth muscle contractility. Five subunits (alpha-1, alpha-2, beta, gamma, and delta) make up the L-type channel. The alpha-1 subunit is the binding site for calcium-based antagonists. Dihydropyridine-based calcium antagonists are used as markers for these binding sites.

Calcium Channels, N-Type [M0328047]
CALCIUM CHANNELS that are concentrated in neural tissue. Omega toxins inhibit the actions of these channels by altering their voltage dependence.

Calcium Channels, P-Type [M0328057]
CALCIUM CHANNELS located within the PURKINJE CELLS of the cerebellum. They are involved in stimulation-secretion coupling of neurons.

Calcium Channels, Q-Type [M0328058]
CALCIUM CHANNELS located in the neurons of the brain.

Calcium Channels, R-Type [M0328063]
CALCIUM CHANNELS located in the neurons of the brain. They are inhibited by the marine snail toxin, omega conotoxin MVIIC.

Calcium Channels, T-Type [M0328068]
A heterogenous group of transient or low voltage activated type CALCIUM CHANNELS. They are found in cardiac myocyte membranes, the sinoatrial node, Purkinje cells of the heart and the central nervous system.

Calcium Pantothenate [M0015822]

Calcium-Binding Protein, Vitamin D-Dependent [M0003191]
A protein that plays a fundamental role in the Vitamin D mediated transport of calcium in reptiles, amphibians, birds and mammals. It is found in the intestine, kidneys, egg shell gland, brain, and possibly other organs. Its molecular weight is species dependent.

Calcium-Binding Proteins [M0003193]
Proteins to which calcium ions are bound. They can act as transport proteins, regulator proteins, or activator proteins. They typically contain EF HAND MOTIFS.

Calcium-Transporting ATPases [M0000393]
Cation-transporting proteins that utilize the energy of ATP hydrolysis for the transport of CALCIUM. They differ from CALCIUM CHANNELS which allow calcium to pass through a membrane without the use of energy.

Caldesmon [M0003215]

Caldesmon (77) [M0003216]

Calelectrins [M0026266]

Calf Thymus Chromatin Protein HMG [M0010346]

Calgranulin A [M0169795]
A 10.8-kDa member of the S-100 family of calcium-binding proteins that can form homo- or heterocomplexes with CALGRANULIN B and a variety of other proteins. The calgranulin A/B heterodimer is known as LEUKOCYTE L1 ANTIGEN COMPLEX. Calgranulin A is found in many cell types including GRANULOCYTES; KERATINOCYTES; and myelomonocytes, and has been shown to act as a chemotactic substance for NEUTROPHILS. Because it is present in acute inflammation but absent in chronic inflammation, it is a useful biological marker for a number of pathological conditions.

Calgranulin B [M0169799]
A 13.2-kDa member of the S-100 family of calcium-binding proteins that can form homo- or heterocomplexes with CALGRANULIN A and a variety of other proteins. The calgranulin A/B heterodimer is known as LEUKOCYTE L1 ANTIGEN COMPLEX. Calgranulin B is expressed at high concentrations in GRANULOCYTES during early monocyte differentiation, and serum calgranulin B levels are elevated in many inflammatory disorders such as CYSTIC FIBROSIS.

Calmodulin [M0003213]
A heat-stable, low-molecular-weight activator protein found mainly in the brain and heart. The binding of calcium ions to this protein allows this protein to bind to cyclic nucleotide phosphodiesterases and to adenyl cyclase with subsequent activation. Thereby this protein modulates cyclic AMP and cyclic GMP levels.

Calmodulin Phosphodiesterase [M0023235]

Calmodulin-Binding Proteins [M0003217]
Proteins which bind calmodulin. They are found in many tissues and have a variety of functions including F-actin cross-linking properties, inhibition of cyclic nucleotide phosphodiesterase and calcium and magnesium ATPases.

Calmodulin-Dependent Phosphodiesterase [M0023236]

Calnexin [M0193588]
A lectin found in ENDOPLASMIC RETICULUM membranes that binds to specific N-linked OLIGOSACCHARIDES found on newly synthesized proteins. It may play role in PROTEIN FOLDING or retention and degradation of misfolded proteins in the endoplasmic reticulum.

Calpactins [M0026267]

Calpain [M0003226]
Cysteine proteinase found in many tissues. Hydrolyzes a variety of endogenous proteins including neuropeptides, cytoskeletal proteins, proteins from smooth muscle, cardiac muscle, liver, platelets and erythrocytes. Two subclasses having high and low calcium sensitivity are known. Removes Z-discs and M-lines from myofibrils. Activates phosphorylase kinase and cyclic nucleotide-independent protein kinase. This enzyme was formerly listed as EC 3.4.22.4.

Calpain I [M0003227]

Calpain II [M0003228]

Calreticulin [M0172278]
A multifunctional protein that is found primarily within membrane-bound organelles. In the ENDOPLASMIC RETICULUM it binds to specific N-linked oligosaccharides found on newly-synthesized proteins and functions as a MOLECULAR CHAPERONE that may play a role in PROTEIN FOLDING or retention and degradation of misfolded proteins. In addition calreticulin is a major storage form for CALCIUM and functions as a calcium-signaling molecule that can regulate intracellular calcium HOMEOSTASIS.

Calsequestrin [M0003229]
Acidic protein found in SARCOPLASMIC RETICULUM that binds calcium to the extent of 700-900 nmoles/mg. It plays the role of sequestering calcium transported to the interior of the intracellular vesicle.

Calspectin [M0003218]

CaM-BP(80) [M0003219]

Camphor 5-Monooxygenase [M0028967]
A soluble cytochrome P-450 enzyme that catalyzes camphor monooxygenation in the presence of putidaredoxin, putidaredoxin reductase, and molecular oxygen. This enzyme, encoded by the CAMC gene also known as CYP101, has been crystallized from bacteria and the structure is well defined. Under anaerobic conditions, this enzyme reduces the polyhalogenated compounds bound at the camphor-binding site.

Canasa [M0474819]

Canavanine [M0003249]

Cancer Vaccines [M0028986]
Vaccines or candidate vaccines designed to prevent or treat cancer. Vaccines are produced using the patient's own whole tumor cells as the source of antigens, or using tumor-specific antigens, often recombinantly produced.

Canderel [M0434513]

Cap-Binding Protein Complex [M0419250]
A heterodimeric protein complex of RNA cap-binding proteins which binds with high affinity to the 5' MRNA CAP STRUCTURE.

Capoten [M0003322]

Capralense [M0432613]

Capreomycin [M0003304]

Capreomycin Sulfate [M0003303]
Cyclic peptide antibiotic similar to VIOMYCIN. It is produced by Streptomyces capreolus.

Caproamin [M0432614]

Caprocid [M0351468]

Caprolest [M0432615]

Capsid Proteins [M0408969]
Proteins that form the CAPSID of VIRUSES.

Captopril [M0003319]
A potent and specific inhibitor of PEPTIDYL-DIPEPTIDASE A. It blocks the conversion of ANGIOTENSIN I to ANGIOTENSIN II, a vasoconstrictor and important regulator of arterial blood pressure. Captopril acts to suppress the RENIN-ANGIOTENSIN SYSTEM and inhibits pressure responses to exogenous angiotensin.

CapZ Actin Capping Protein [M0188281]
An actin capping protein that binds to the barbed-ends of ACTIN filaments. It is a heterodimer consisting of an alpha and a beta subunit. It regulates actin assembly by stabilizing actin oligomers for elongation. In SKELETAL MUSCLE, CapZ is localized to the Z-disk.

CapZ Actin Capping Protein, alpha Subunit [M0188278]

CapZ Actin Capping Protein, beta Subunit [M0188279]

Carbamoyl-Phosphate Synthase (Ammonia) [M0003332]
An enzyme that catalyzes the formation of carbamoyl phosphate from ATP, carbon dioxide, and ammonia. This enzyme is specific for arginine biosynthesis or the urea cycle. Absence or lack of this enzyme may cause CARBAMOYL-PHOSPHATE SYNTHASE I DEFICIENCY DISEASE. EC 6.3.4.16.

Carbamoyl-Phosphate Synthase (Glutamine-Hydrolyzing) [M0003334]
An enzyme that catalyzes the formation of carbamoyl phosphate from ATP, carbon dioxide, and glutamine. This enzyme is important in the de novo biosynthesis of pyrimidines. EC 6.3.5.5.

Carbamoyltransferases [M0029515]

Carbamyl Phosphate Synthase II [M0003333]

Carbenicillinase [M0016148]

Carbocysteine [M0003348]
A compound formed when iodoacetic acid reacts with sulfhydryl groups in proteins. It has been used as an anti-infective nasal spray with mucolytic and expectorant action.

Carbocysteine, L-Isomer [M0330922]

Carbohydrate Dehydrogenases [M0003355]
Reversibly catalyze the oxidation of a hydroxyl group of carbohydrates to form a keto sugar, aldehyde or lactone. Any acceptor except molecular oxygen is permitted. Includes EC 1.1.1.; EC 1.1.2.; and 1.1.99.

Carbohydrate Epimerases [M0003356]
Enzymes that catalyze the epimerization of chiral centers within carbohydrates or their derivatives. EC 5.1.3.

Carbon-Carbon Double Bond Isomerases [M0029315]
Enzymes that catalyze the shifting of a carbon-carbon double bond from one position to another within the same molecule. EC 5.3.3.

Carbon-Carbon Ligases [M0029296]
Enzymes that catalyze the joining of two molecules by the formation of a carbon-carbon bond. These are the carboxylating enzymes and are mostly biotinyl-proteins. EC 6.4.

Carbon-Carbon Lyases [M0029319]
Enzymes that catalyze the cleavage of a carbon-carbon bond by means other than hydrolysis or oxidation. This subclass contains the DECARBOXYLASES, the ALDEHYDE-LYASES, and the OXO-ACID-LYASES. EC 4.1.

Carbon-Nitrogen Ligases [M0029293]
Enzymes that catalyze the joining of two molecules by the formation of a carbon-nitrogen bond. EC 6.3.

Carbon-Nitrogen Ligases with Glutamine as Amide-N-Donor [M0029295]
Enzymes that catalyze the joining of glutamine-derived ammonia and another molecule. The linkage is in the form of a carbon-nitrogen bond. EC 6.3.5.

Carbon-Nitrogen Lyases [M0029321]
Enzymes that catalyze the cleavage of a carbon-nitrogen bond by means other than hydrolysis or oxidation. Subclasses are the AMMONIA-LYASES, the AMIDINE-LYASES, the amine-lyases, and other carbon-nitrogen lyases. EC 4.3.

Carbon-Oxygen Ligases [M0029291]
Enzymes that catalyze the joining of two molecules by the formation of a carbon-oxygen bond. EC 6.1.

Carbon-Oxygen Lyases [M0029320]
Enzymes that catalyze the cleavage of a carbon-oxygen bond by means other than hydrolysis or oxidation. EC 4.2.

Carbon-Sulfur Ligases [M0029292]
Enzymes that catalyze the joining of two molecules by the formation of a carbon-sulfur bond. EC 6.2.

Carbon-Sulfur Lyases [M0020767]
Enzymes that catalyze the cleavage of a carbon-sulfur bond by means other than hydrolysis or oxidation. EC 4.4.

Carbonic Anhydrase I [M0003387]
A cytosolic carbonic anhydrase isoenzyme primarily expressed in ERYTHROCYTES, vascular endothelial cells, and the gastrointestinal mucosa. EC 4.2.1.-

Carbonic Anhydrase II [M0003388]
A cytosolic carbonic anhydrase isoenzyme found widely distributed in cells of almost all tissues. Deficiencies of carbonic anhydrase II produce a syndrome characterized by OSTEOPETROSIS, renal tubular acidosis (ACIDOSIS, RENAL TUBULAR) and cerebral calcification. EC 4.2.1.-

Carbonic Anhydrase III [M0003389]
A cytosolic carbonic anhydrase isoenzyme primarily expressed in skeletal muscle (MUSCLES, SKELETAL). EC 4.2.1.-

Carbonic Anhydrase IV [M0389743]
A membrane-bound carbonic anhydrase found in lung capillaries and kidney.

Carbonic Anhydrase V [M0003395]
A carbonic anhydrase isoenzyme found in MITOCHONDRIA where it provides bicarbonate ions that are components in the urea cycle and in GLUCONEOGENESIS.

Carbonic Anhydrases [M0003382]
A family of zinc-containing enzymes that catalyze the reversible hydration of carbon dioxide. They play an important role in the transport of CARBON DIOXIDE from the tissues to the LUNG. EC 4.2.1.1.

Carboxy-Lyases [M0003401]
Enzymes that catalyze the addition of a carboxyl group to a compound (carboxylases) or the removal of a carboxyl group from a compound (decarboxylases). EC 4.1.1.

Carboxyhemoglobin [M0003402]

Carboxyhemoglobin A [M0003403]

Carboxyhemoglobin C [M0003404]

Carboxyl and Carbamoyl Transferases [M0029517]
A group of enzymes that catalyze the transfer of carboxyl- or carbamoyl- groups. EC 2.1.3.

Carboxylesterase [M0090456]
Carboxylesterase is a serine-dependent esterase with wide substrate specificity. The enzyme is involved in the detoxification of XENOBIOTICS and the activation of ester and of amide PRODRUGS.

Carboxylic Ester Hydrolases [M0003406]
Enzymes which catalyze the hydrolysis of carboxylic acid esters with the formation of an alcohol and a carboxylic acid anion.

Carboxyltransferases [M0029516]

Carboxymethylcysteine [M0003349]

Carboxypeptidase A1 [M0449102]

Carboxypeptidase A2 [M0449105]

Carboxypeptidase A5 [M0449103]

Carboxypeptidase B [M0072754]
A ZINC-dependent carboxypeptidase primary found in the DIGESTIVE SYSTEM. The enzyme catalyzes the preferential cleavage of a C-terminal peptidyl-L-lysine or arginine. It was formerly classified as EC 3.4.2.2 and EC 3.4.12.3.

Carboxypeptidase C [M0242181]
A carboxypeptidase that catalyzes the release of a C-terminal amino acid with a broad specificity. It also plays a role in the LYSOSOMES by protecting BETA-GALACTOSIDASE and NEURAMINIDASE from degradation. It was formerly classified as EC 3.4.12.1 and EC 3.4.21.13.

Carboxypeptidase G1 [M0018074]

Carboxypeptidase G2 [M0018075]

Carboxypeptidase H [M0108540]
A ZINC-containing exopeptidase primarily found in SECRETORY VESICLES of endocrine and neuroendocrine cells. It catalyzes the cleavage of C-terminal ARGININE or LYSINE residues from polypeptides and is active in processing precursors of PEPTIDE HORMONES and other bioactive peptides.

Carboxypeptidase U [M0376430]
A metallocarboxypeptidase that removes C-terminal lysine and arginine from biologically active peptides and proteins thereby regulating their activity. It is a zinc enzyme with no preference shown for lysine over arginine. Pro-carboxypeptidase U in human plasma is activated by thrombin or plasmin during clotting to form the unstable carboxypeptidase U.

Carboxypeptidases [M0003411]
Enzymes that act at a free C-terminus of a polypeptide to liberate a single amino acid residue. They are further divided based on their catalytic mechanism into serine-type carboxypeptidases EC 3.4.16; metallocarboxypeptidases, EC 3.4.17; and cysteine-type carboxypeptidases, EC 3.4.18. EC 3.4.-.

Carboxypeptidases A [M0072752]
Carboxypeptidases that are primarily found the DIGESTIVE SYSTEM that catalyze the release of C-terminal amino acids. Carboxypeptidases A have little or no activity for hydrolysis of C-terminal ASPARTIC ACID; GLUTAMIC ACID; ARGININE; LYSINE; or PROLINE. This enzyme requires ZINC as a cofactor and was formerly listed as EC 3.4.2.1 and EC 3.4.12.2.

CARD Signaling Adaptor Proteins [M0493302]
A family of intracellular signaling adaptor proteins that contain caspase activation and recruitment domains. Proteins that contain this domain play a role in APOPTOSIS-related signal transduction by associating with other CARD domain-containing members and in activating INITIATOR CASPASES that contain CARD domains within their N-terminal pro-domain region.

Cardiac Myosins [M0371559]
Myosin type II isoforms found in cardiac muscle.

Carnitine Acyltransferases [M0003496]
Acyltransferases in the inner mitochondrial membrane that catalyze the reversible transfer of acyl groups from acyl-CoA to L-carnitine and thereby mediate the transport of activated fatty acids through that membrane. EC 2.3.1.

Carnitine O-Acetyltransferase [M0003495]
An enzyme that catalyzes the formation of O-acetylcarnitine from acetyl-CoA plus carnitine. EC 2.3.1.7.

Carnitine O-Palmitoyltransferase [M0003498]
An enzyme that catalyzes reversibly the conversion of palmitoyl-CoA to palmitoylcarnitine in the inner mitochondrial membrane. EC 2.3.1.21.

Carnitine Palmitoyltransferase I [M0003499]

Carnitine Palmitoyltransferase II [M0003500]

Carnitine-Acetylcarnitine Translocase [M0003497]

Carnosine [M0003535]
A naturally occurring dipeptide neuropeptide found in muscles.

Carnosine, (D-His)-Isomer [M0330928]

Carrier Proteins [M0003559]
Transport proteins that carry specific substances in the blood or across cell membranes.

Casein A [M0003589]

Casein Kinase 2 alpha Subunit [M0444965]

Casein Kinase 2 alpha' Subunit [M0460745]

Casein Kinase 2 beta Subunit [M0460746]

Casein Kinase I [M0072783]
A casein kinase that was originally described as a monomeric enzyme with a molecular weight of 30-40 kD. Several ISOENZYMES of casein kinase I have been found which are encoded by separate genes. Many of the casein kinase I isoenzymes have been shown to play distinctive roles in intracellular SIGNAL TRANSDUCTION.

Casein Kinase Ialpha [M0072784]
A casein kinase I isoenzyme that plays a role in intracellular signaling pathways including the CELL CYCLE, membrane trafficking, and RNA processing. In DROSOPHILA casein kinase Ialpha has been in regulation of Hedghog and Wingless signaling pathways. Multiple isoforms of casein kinase Ialpha exist and are due ALTERNATIVE SPLICING.

Casein Kinase IalphaL [M0072785]

Casein Kinase IalphaLS [M0072786]

Casein Kinase IalphaS [M0072787]

Casein Kinase Ibeta [M0072788]

Casein Kinase Idelta [M0440974]
A casein kinase I isoenzyme that plays a regulatory role in a variety of cellular functions including vesicular transport, CHROMOSOME SEGREGATION; CYTOKINESIS, developmental processes, and the CIRCADIAN RHYTHM.

Casein Kinase Iepsilon [M0072789]
A casein kinase I isoenzyme with specificity for proteins involved the regulation of the CIRCADIAN RHYTHM.

Casein Kinase Igamma [M0072790]

Casein Kinase II [M0232027]
A ubiquitous casein kinase that is comprised of two distinct catalytic subunits and dimeric regulatory subunit. Casein kinase II has been shown to phosphorylate a large number of substrates, many of which are proteins involved in the regulation of gene expression.

Casein Kinase Ikappa [M0072792]

Casein Kinase Itau [M0361581]

Casein Kinases [M0072796]
A group of protein-serine-threonine kinases that was originally identified as being responsible for the PHOSPHORYLATION of CASEINS. They are ubiquitous enzymes that have a preference for acidic proteins. Casein kinases play a role in SIGNAL TRANSDUCTION by phosphorylating a variety of regulatory cytoplasmic and regulatory nuclear proteins.

Casein Phosphatase [M0016691]

Caseins [M0003590]
A mixture of related phosphoproteins occurring in milk and cheese. The group is characterized as one of the most nutritive milk proteins, containing all of the common amino acids and rich in the essential ones.

CASP8 and FADD-Like Apoptosis Regulating Protein [M0278135]
An APOPTOSIS-regulating protein that is structurally related to CASPASE 8 and competes with CASPASE 8 for binding to FAS ASSOCIATED DEATH DOMAIN PROTEIN. Two forms of CASP8 and FADD-like apoptosis regulating protein exist, a long form containing a caspase-like enzymatically inactive domain and a short form which lacks the caspase-like domain.

Caspase 1 [M0029892]
A long pro-domain caspase that has specificity for the precursor form of INTERLEUKIN-1BETA. It plays a role in INFLAMMATION by catalytically converting the inactive forms of CYTOKINES such as interleukin-1beta to their active, secreted form. Caspase 1 is referred as interleukin-1beta converting enzyme and is frequently abbreviated ICE.

Caspase 10 [M0296687]
A long pro-domain caspase that contains a death effector domain in its pro-domain region. Activation of this enzyme can occur via the interaction of its N-terminal death effector domain with DEATH DOMAIN RECEPTOR SIGNALING ADAPTOR PROTEINS. Caspase 10 plays a role in APOPTOSIS by cleaving and activating EFFECTOR CASPASES. Several isoforms of this protein exist due to multiple alternative splicing of its MESSENGER RNA.

Caspase 10a [M0266009]

Caspase 10c [M0303870]

Caspase 10d [M0303912]

Caspase 12 [M0355943]
A long pro-domain caspase that contains a caspase recruitment domain in its pro-domain region. Caspase 9 is activated by pro-apoptotic factors that are released during cell stress and by CARD SIGNALING ADAPTOR PROTEINS. It activates APOPTOSIS by cleaving and activating EFFECTOR CASPASES.

Caspase 14 [M0297648]
A short pro-domain caspase that is almost exclusively expressed in the EPIDERMIS and may play a role in the differentiation of epidermal KERATINOCYTES.

Caspase 2 [M0236588]
A long pro-domain caspase that contains a caspase recruitment domain in its pro-domain region. Activation of this enzyme can occur via the interaction of its caspase recruitment domain with CARD SIGNALING ADAPTOR PROTEINS. Caspase 2 plays a role in APOPTOSIS by cleaving and activating effector pro-caspases. Several isoforms of this protein exist due to multiple alternative splicing of its MESSENGER RNA.

Caspase 2 Subunit p12 [M0491616]

Caspase 2 Subunit p13 [M0491615]

Caspase 2 Subunit p18 [M0491614]

Caspase 3 [M0239778]
A short pro-domain caspase that plays an effector role in APOPTOSIS. It is activated by INITIATOR CASPASES such as CASPASE 9. Isoforms of this protein exist due to multiple alternative splicing of its MESSENGER RNA.

Caspase 6 [M0275238]
A short pro-domain caspase that plays an effector role in APOPTOSIS. It is activated by INITIATOR CASPASES such as CASPASE 7; CASPASE 8; and CASPASE 10. Isoforms of this protein exist due to multiple alternative splicing of its MESSENGER RNA.

Caspase 7 [M0275104]
A short pro-domain caspase that plays an effector role in APOPTOSIS. It is activated by INITIATOR CASPASES such as CASPASE 3 and CASPASE 10. Several isoforms of this protein exist due to multiple alternative splicing of its MESSENGER RNA.

Caspase 8 [M0283158]
A long pro-domain caspase that contains a death effector domain in its pro-domain region. Caspase 8 plays a role in APOPTOSIS by cleaving and activating EFFECTOR CASPASES. Activation of this enzyme can occur via the interaction of its N-terminal death effector domain with DEATH DOMAIN RECEPTOR SIGNALING ADAPTOR PROTEINS.

Caspase 9 [M0264023]
A long pro-domain caspase that contains a caspase recruitment domain in its pro-domain region. Caspase 9 is activated during cell stress by mitochondria-derived proapoptotic factors and by CARD SIGNALING ADAPTOR PROTEINS such as APOPTOTIC PROTEASE-ACTIVATING FACTOR 1. It activates APOPTOSIS by cleaving and activating EFFECTOR CASPASES.

Caspases [M0029891]
A family of intracellular CYSTEINE ENDOPEPTIDASES that play a role in regulating INFLAMMATION and APOPTOSIS. They specifically cleave peptides at a CYSTEINE amino acid that follows an ASPARTIC ACID residue. Caspases are activated by proteolytic cleavage of a precursor form to yield large and small subunits that form the enzyme. Since the cleavage site within precursors matches the specificity of caspases, sequential activation of precursors by activated caspases can occur.

Caspases, Effector [M0491613]
A subclass of caspases that contain short pro-domain regions. They are activated by the proteolytic action of INITIATOR CASPASES. Once activated they cleave a variety of substrates that cause APOPTOSIS.

Caspases, Initiator [M0491612]
A subtype of caspases that contain long pro-domain regions that regulate the activation of the enzyme. The pro-domain regions contain protein-protein interaction motifs that can interact with specific signaling adaptor proteins such as DEATH DOMAIN RECEPTORS; DED SIGNALING ADAPTOR PROTEINS; and CARD SIGNALING ADAPTOR PROTEINS. Once activated, the initiator caspases can activate other caspases such as the EFFECTOR CASPASES.

Catalase [M0003613]
An oxidoreductase that catalyzes the conversion of HYDROGEN PEROXIDE to water and oxygen. It is present in many animal cells. A deficiency of this enzyme results in ACATALASIA.

Catalase A [M0003614]

Catalase T [M0003615]

Catalytic Subunit Cyclic AMP-Dependent Protein Kinase [M0026997]

Catechol 1,2-Dioxygenase [M0072800]
An enzyme that catalyzes the oxidation of catechol to muconic acid with the use of Fe3+ as a cofactor. This enzyme was formerly characterized as EC 1.13.1.1 and EC 1.99.2.2.

Catechol 2,3-Dioxygenase [M0072809]
Catalyzes the oxidation of catechol to 2-hydroxymuconate semialdehyde in the CARBAZOLE and BENZOATE degradation via HYDROXYLATION pathways. It also catalyzes the conversion of 3-methylcatechol to cis, cis-2-hydroxy-6-oxohept-2,4-dienoate in the TOLUENE and XYLENE degradation pathway. This enzyme was formerly characterized as EC 1.13.1.2.

Catechol O-Methyltransferase [M0003646]
Enzyme that catalyzes the movement of a methyl group from S-adenosylmethionone to a catechol or a catecholamine. EC 2.1.1.6.

Catechol Oxidase [M0006511]
An enzyme of the oxidoreductase class that catalyzes the reaction between catechol and oxygen to yield benzoquinone and water. It is a complex of copper-containing proteins that acts also on a variety of substituted catechols. EC 1.10.3.1.

Catecholamine Plasma Membrane Transport Proteins [M0475596]
A group of membrane transport proteins that transport biogenic amine derivatives of catechol across the PLASMA MEMBRANE. Catecholamine plasma membrane transporter proteins regulate neural transmission as well as catecholamine metabolism and recycling.

Catecholamine Sulfotransferase A [M0023421]

Catecholamine Sulfotransferase B [M0023422]

Catenins [M0479529]
A family of cytoskeletal proteins that play essential roles in CELL ADHESION at ADHERENS JUNCTIONS by linking CADHERINS to the ACTIN FILAMENTS of the CYTOSKELETON.

Catgut [M0003653]
Sterile collagen strands obtained from healthy mammals. They are used as absorbable surgical ligatures and are frequently impregnated with chromium or silver for increased strength. They tend to cause tissue reaction.

Cathepsin B [M0003657]
A lysosomal cysteine proteinase which hydrolyzes proteins, with a specificity resembling that of papain. The enzyme is present in a variety of tissues and is important in many physiological and pathological processes. In pathology, cathepsin B has been found to be involved in demyelination, emphysema, rheumatoid arthritis, and neoplastic infiltration. EC 3.4.22.1.

Cathepsin B-Like Activity [M0003658]

Cathepsin B-Like Proteinase [M0003659]

Cathepsin D [M0003660]
An intracellular proteinase found in a variety of tissue. It has specificity similar to but narrower than that of pepsin A. The enzyme is involved in catabolism of cartilage and connective tissue. EC 3.4.23.5. (Formerly EC 3.4.4.23).

Cathepsin E [M0029767]
An aspartic endopeptidase of the hydrolase class that is similar to cathepsin D but has a slightly broader specificity. EC 3.4.23.34.

Cathepsins [M0003661]
A group of lysosomal proteinases or endopeptidases found in aqueous extracts of a variety of animal tissue. They function optimally within an acidic pH range.

Cation Exchange Proteins [M0381291]

Cation Pump [M0025340]

Cation Transport Proteins [M0380835]
Membrane proteins whose primary function is to facilitate the transport of positively charged molecules (cations) across a biological membrane.

Cationic Amino Acid Transporter 1 [M0199991]
A high-affinity, low capacity system y+ amino acid transporter found ubiquitously. It has specificity for the transport of ARGININE; LYSINE; and ORNITHINE. It may also act as an ecotropic leukemia retroviral receptor.

Cationic Amino Acid Transporter 2 [M0199992]
A high-affinity, low capacity system y+ amino acid transporter with strong similarity to CATIONIC AMINO ACID TRANSPORTER 1. The two isoforms of the protein, CAT-2A and CAT-2B, exist due to alternative mRNA splicing. The transporter has specificity for the transport of ARGININE; LYSINE; and ORNITHINE.

Cationic Amino Acid Transporter 2A [M0379737]

Cationic Amino Acid Transporter 2B [M0379738]

Caveolin 1 [M0209023]
A tyrosine phosphoprotein that plays an essential role in CAVEOLAE formation. It binds CHOLESTEROL and is involved in LIPIDS transport, membrane traffic, and SIGNAL TRANSDUCTION.

Caveolin 2 [M0271571]
Caveolin 2 is a binding partner of CAVEOLIN 1. It undergoes tyrosine phosphorylation by C-SRC PROTEIN PP60 and plays a regulatory role in CAVEOLAE formation.

Caveolin 3 [M0257250]
A caveolin that is expressed exclusively in MUSCLE CELLS and is sufficient to form CAVEOLAE in SARCOLEMMA. Mutations in caveolin 3 are associated with multiple muscle diseases including DISTAL MYOPATHY and LIMB-GIRDLE MUSCULAR DYSTROPHY.

Caveolins [M0358285]
The main structural proteins of CAVEOLAE. Several distinct genes for caveolins have been identified.

CCAAT-Binding Factor [M0156235]
A heterotrimeric DNA-binding protein that binds to CCAAT motifs in the promoters of eukaryotic genes. It is composed of three subunits: A, B and C.

CCAAT-Binding Factor, A-Subunit [M0156236]

CCAAT-Binding Factor, B-Subunit [M0156237]

CCAAT-Binding Factor, C-Subunit [M0156238]

CCAAT-Enhancer-Binding Protein-alpha [M0164348]
A CCAAT-enhancer-binding protein found in LIVER; ADIPOSE TISSUE; INTESTINES; LUNG; ADRENAL GLANDS; PLACENTA; OVARY and peripheral blood mononuclear cells (LEUKOCYTES, MONONUCLEAR). Experiments with knock-out mice have demonstrated that CCAAT-enhancer binding protein-alpha is essential for the functioning and differentiation of HEPATOCYTES and ADIPOCYTES.

CCAAT-Enhancer-Binding Protein-beta [M0164346]
A CCAAT-enhancer-binding protein found in LIVER; INTESTINES; LUNG and ADIPOSE TISSUE. It is an important mediator of INTERLEUKIN-6 signaling.

CCAAT-Enhancer-Binding Protein-delta [M0191519]
A member of the C-EBP protein family of transcription factors. It plays a key role in G0 PHASE mammary EPITHELIAL CELL growth arrest, and it is involved in transcriptional regulation of INTERLEUKIN 1; INTERLEUKIN 6; and TUMOR NECROSIS FACTOR-ALPHA.

CCAAT-Enhancer-Binding Proteins [M0164365]
A class of proteins that were originally identified by their ability to bind the DNA sequence CCAAT. The typical CCAAT-enhancer binding protein forms dimers and consists of an activation domain, a DNA-binding basic region, and a leucine-rich dimerization domain (LEUCINE ZIPPERS). CCAAT-BINDING FACTOR is structurally distinct type of CCAAT-enhancer binding protein consisting of a trimer of three different subunits.

CCK-33 [M0004236]

CCK-4 Receptors [M0443800]

CCK-8 Receptors [M0443799]

CD30 Ligand [M0218957]
A membrane-bound tumor necrosis family member found primarily on activated T-LYMPHOCYTES that binds specifically to CD30 ANTIGEN. It may play a role in INFLAMMATION and immune regulation.

CD32 Antigens [M0026478]

CD4 Immunoadhesins [M0025662]
Chimeric molecules resulting from the fusion of recombinant soluble CD4 to the Fc portion of immunoglobulins. These have potential use in the therapy of AIDS since they possess both the gp120-binding and HIV-blocking properties of rCD4 as well as the long plasma half-life and Fc receptor-binding functions of immunoglobulin.

CD4-IgG [M0025663]

CD40 Ligand [M0200619]
A membrane glycoprotein and differentiation antigen expressed on the surface of T-cells that binds to CD40 ANTIGENS on B-LYMPHOCYTES and induces their proliferation. Mutation of the gene for CD40 ligand is a cause of HYPER-IGM IMMUNODEFICIENCY SYNDROME, TYPE 1.

CD42b Antigens [M0028421]

CD42c Antigens [M0028422]

CD42d Antigen [M0028423]

CD45R Antigens [M0026538]

CD45RA Antigens [M0026540]

CD45RB Antigens [M0026541]

CD45RCAntigens [M0026544]

CD45RO Antigens [M0026542]

CD64 Antigens [M0026481]

CDC2 Protein Kinase [M0024739]
Phosphoprotein with protein kinase activity that functions in the G2/M phase transition of the CELL CYCLE. It is the catalytic subunit of the MATURATION-PROMOTING FACTOR and complexes with both CYCLIN A and CYCLIN B in mammalian cells. The maximal activity of cyclin-dependent kinase 1 is achieved when it is fully dephosphorylated.

CDC2-CDC28 Kinases [M0442126]
A family of cell cycle-dependent kinases that are related in structure to CDC28 PROTEIN KINASE; S CEREVISIAE; and the CDC2 PROTEIN KINASE found in mammalian species.

CDC2-Related Kinases [M0374710]

cdc25 Phosphatase [M0328156]
A tyrosine phosphatase required for progression of the cell cycle. It is required for p34(cdc2) kinase activation.

CDC28 Protein Kinase, S cerevisiae [M0026531]
A protein kinase encoded by the Saccharomyces cerevisiae CDC28 gene and required for progression from the G1 PHASE to the S PHASE in the CELL CYCLE.

CDC28-Related Kinases [M0442127]

cdc42 GTP-Binding Protein [M0328159]
A member of the Rho family of MONOMERIC GTP-BINDING PROTEINS. It is associated with a diverse array of cellular functions including cytoskeletal changes, filopodia formation and transport through the GOLGI APPARATUS. This enzyme was formerly listed as EC 3.6.1.47.

cdc42 GTP-Binding Protein, Saccharomyces cerevisiae [M0328166]
A member of the Rho family of MONOMERIC GTP-BINDING PROTEINS from SACCHAROMYCES CEREVISIAE. It is involved in morphological events related to the cell cycle. This enzyme was formerly listed as EC 3.6.1.47.

cdc42 GTP-Binding Protein, Yeast [M0389144]

CDP-Diacylglycerol-Inositol 3-Phosphatidyltransferase [M0072823]
An enzyme that catalyzes the formation of PHOSPHATIDYLINOSITOL and CMP from CDP-DIACYLGLYCEROL and MYOINOSITOL.

CDPdiacylglycerol-Serine O-Phosphatidyltransferase [M0016649]
An enzyme that catalyzes the formation of phosphatidylserine and CMP from CDPdiglyceride plus serine. EC 2.7.8.8.

CDw32 Antigens [M0026480]

Celiase [M0020585]

Celiomycin [M0373268]

Cell Adhesion Molecules [M0024220]
Surface ligands, usually glycoproteins, that mediate cell-to-cell adhesion. Their functions include the assembly and interconnection of various vertebrate systems, as well as maintenance of tissue integration, wound healing, morphogenic movements, cellular migrations, and metastasis.

Cell Adhesion Molecules, Neuron-Glia [M0028455]
Cell adhesion molecules that mediate neuron-neuron adhesion and neuron-astrocyte adhesion. They are expressed on neurons and Schwann cells, but not astrocytes and are involved in neuronal migration, neurite fasciculation, and outgrowth. Ng-CAM is immunologically and structurally distinct from NCAM.

Cell Adhesion Molecules, Neuronal [M0024226]
Surface ligands that mediate cell-to-cell adhesion and function in the assembly and interconnection of the vertebrate nervous system. These molecules promote cell adhesion via a homophilic mechanism. These are not to be confused with NEURAL CELL ADHESION MOLECULES, now known to be expressed in a variety of tissues and cell types in addition to nervous tissue.

Cell Cycle Proteins [M0028143]
Proteins that control the CELL DIVISION CYCLE. This family of proteins includes a wide variety of classes, including CYCLIN-DEPENDENT KINASES, mitogen-activated kinases, CYCLINS, and phosphoprotein phosphatases (PHOSPHOPROTEIN PHOSPHATASE) as well as their putative substrates such as chromatin-associated proteins, CYTOSKELETAL PROTEINS, and TRANSCRIPTION FACTORS.

Cell Membrane Proteins [M0013342]

Cell Surface Proteins [M0013343]

Cellobiohydrolase A [M0445567]

Cellobiohydrolase I [M0445560]

Cellobiohydrolase II [M0445561]

Cellular Apoptosis Susceptibility Protein [M0253556]
A nucleocytoplasmic transport protein that binds to ALPHA KARYOPHERINS and RAN GTP BINDING PROTEIN inside the CELL NUCLEUS and participates in their export into CYTOPLASM. It is also associated with the regulation of APOPTOSIS and microtubule assembly.

Cellular Retinol Binding Protein [M0018963]

Cellulase [M0003782]
An endocellulase with specificity for the hydrolysis of 1,4-beta-glucosidic linkages in CELLULOSE, lichenin, and cereal beta-glucans.

Cellulases [M0445478]
A family of glycosidases that hydrolyse crystalline CELLULOSE into soluble sugar molecules. Within this family there are a variety of enzyme subtypes with differing substrate specificities that must work together to bring about complete cellulose hydrolysis. They are found in structures called CELLULOSOMES.

Cellulose 1,4-beta-Cellobiosidase [M0073551]
An exocellulase with specificity for the hydrolysis of 1,4-beta-D-glucosidic linkages in CELLULOSE and cellotetraose. It catalyzes the hydrolysis of terminal non-reducing ends of beta-D-glucosides with release of CELLOBIOSE.

Centromere Protein B [M0147025]
A DNA-binding protein that interacts with a 17-base pair sequence known as the CENP-B box motif. The protein is localized constitutively to the CENTROMERE and plays an important role in its maintenance.

Cephalexin Amidase [M0003826]

Cephalosporin Acylase [M0016129]

Cephalosporinase [M0003825]

Ceramide Trihexosidase [M0003837]
An enzyme that catalyzes the hydrolysis of a ceramidetrihexoside to a ceramidedihexoside plus galactose. EC 3.2.1.47.

Ceramide-Diglyceride Kinase [M0029462]

Cerebroside Sulfate Activator Protein [M0063217]

Cerebroside-Sulfatase [M0003905]
An enzyme that catalyzes the hydrolysis of cerebroside 3-sulfate (sulfatide) to yield a cerebroside and inorganic sulfate. A marked deficiency of arylsulfatase A, which is considered the heat-labile component of cerebroside sulfatase, has been demonstrated in all forms of metachromatic leukodystrophy (LEUKODYSTROPHY, METACHROMATIC). EC 3.1.6.8.

Cerebrospinal Fluid Proteins [M0003908]
Proteins in the cerebrospinal fluid, normally albumin and globulin present in the ratio of 8 to 1. Increases in protein levels are of diagnostic value in neurological diseases. (Brain and Bannister's Clinical Neurology, 7th ed, p221)

Ceruloplasmin [M0003926]

Chalones [M0009655]
Peptides that inhibit mitosis (ANTIMITOTICS). During the 1960's the term referred to crude extracts that inhibited cell proliferation; the activity was later attributed to PYROGLUTAMATE type oligopeptides.

Chaperonin 10 [M0028190]
Members of the chaperonin heat-shock protein family. Chaperonin 10 purified from bacteria, plastids, or mitochondria occurs as an oligomer of seven identical subunits arranged in a single ring.

Chaperonin 60 [M0028189]
Members of the chaperonin heat-shock protein family. Chaperonin 60 purified from bacteria, plastids, or mitochondria is an oligomeric protein with a distinctive structure of fourteen subunits, arranged in two rings of seven subunits each.

Chaperonins [M0028187]
A class of sequence-related MOLECULAR CHAPERONES found in bacteria, mitochondria, and plastids. Chaperonins are abundant constitutive proteins that increase in amount after stresses such as heat shock, bacterial infection of macrophages, and an increase in the cellular content of unfolded proteins. Bacterial chaperonins are major immunogens in human bacterial infections because of their accumulation during the stress of infection. Two members of this class of chaperones are CHAPERONIN 10 and CHAPERONIN 60.

Charybdotoxin [M0028373]
A 37-amino acid residue peptide isolated from the scorpion Leiurus quinquestriatus hebraeus. It is a neurotoxin that inhibits calcium activated potassium channels.

Chemokine CCL2 [M0028301]
A chemokine that is a chemoattractant for human MONOCYTES and may also cause cellular activation of specific functions related to host defense. It is produced by LEUKOCYTES of both monocyte and lymphocyte lineage and by FIBROBLASTS during tissue injury.

Chemokines [M0028294]
Class of pro-inflammatory cytokines that have the ability to attract and activate leukocytes. They can be divided into at least three structural branches: C; (CHEMOKINES, C); CC; (CHEMOKINES, CC); and CXC; (CHEMOKINES, CXC); according to variations in a shared cysteine motif.

Chemokines, C [M0029311]
Group of chemokines without adjacent cysteines that are chemoattractants for lymphocytes only.

Chemokines, CC [M0029309]
Group of chemokines with adjacent cysteines that are chemoattractants for lymphocytes, monocytes, eosinophils, basophils but not neutrophils.

Chemokines, CX3C [M0328439]
Group of chemokines with the first two cysteines separated by three amino acids. CX3C chemokines are chemotactic for natural killer cells, monocytes, and activated T-cells.

Chemokines, CXC [M0029310]
Group of chemokines with paired cysteines separated by a different amino acid. CXC chemokines are chemoattractants for neutrophils but not monocytes.

Chemolase [M0333217]

Chimeric Proteins, Recombinant [M0026389]

Chimerin 1 [M0328168]
A GTPase activating protein that is specific for RAC GTP-BINDING PROTEINS. It is expressed primarily in the brain and may be involved in signal transduction. The alternatively spliced form of CHIMERIN 1 (alpha-2 Chimerin) contains an additional src homology domain and is expressed in both the brain and testes.

Chimerin Proteins [M0328173]
A family of GTPASE-ACTIVATING PROTEINS that are specific for RAC GTP-BINDING PROTEINS.

Chitin Synthase [M0004100]
An enzyme that converts UDP glucosamine into chitin and UDP. EC 2.4.1.16.

Chitin Synthase 1 [M0004102]

Chitin Synthetase 2 [M0004101]

Chitinase [M0004103]

Chloramphenicol O-Acetyltransferase [M0023862]
An enzyme that catalyzes the acetylation of chloramphenicol to yield chloramphenicol 3-acetate. Since chloramphenicol 3-acetate does not bind to bacterial ribosomes and is not an inhibitor of peptidyltransferase, the enzyme is responsible for the naturally occurring chloramphenicol resistance in bacteria. The enzyme, for which variants are known, is found in both gram-negative and gram-positive bacteria. EC 2.3.1.28.

Chloride Channels [M0027322]
Cell membrane glycoproteins selective for chloride ions.

Chloride Peroxidase [M0004141]
An enzyme that catalyzes the chlorination of a range of organic molecules, forming stable carbon-chloride bonds. EC 1.11.1.10.

Chloride-Bicarbonate Antiporters [M0124849]
Membrane proteins that allow the exchange of chloride ions for bicarbonate ions across the cellular membrane. The action of specific antiporters in this class serve important functions such as allowing the efficient exchange of bicarbonate across red blood cell membranes as they passage through capillaries and the reabsorption of bicarbonate ions by the kidney.

Chlorophyll a-Proteins [M0024716]

Chlorophyll ab-Proteins [M0024717]

Chlorophyll ac-Proteins [M0024718]

Chlorophyll Binding Proteins [M0024719]

Chloroplast Coupling Factor 0 [M0376151]

Chloroplast Coupling Factor 1 [M0376150]

Chloroplast Elongation Factor Tu [M0016219]
RN should be EC 3.6.1.-

Chloroplast Initiation Factors [M0419869]
Peptide initiation factors found in CHLOROPLASTS. Although specific factors may closely resemble those found in prokaryotes, they are eukaryotic factors and classed here under eukaryotic initiation factors.

Chloroplast Proton-Translocating ATPases [M0009729]
Proton-translocating ATPases which produce ADENOSINE TRIPHOSPHATE in plants. They derive energy from light-driven reactions that develop high concentrations of protons within the membranous cisternae (THYLAKOIDS) of the CHLOROPLASTS.

Chlorpheniramine Tannate [M0423769]

Cholase [M0004301]

Cholecystokinin [M0004235]
A peptide, of about 33 amino acids, secreted by the upper INTESTINAL MUCOSA and also found in the central nervous system. It causes gallbladder contraction, release of pancreatic exocrine (or digestive) enzymes, and affects other gastrointestinal functions. Cholecystokinin may be the mediator of satiety.

Cholera Toxin [M0004245]
An ENTEROTOXIN from VIBRIO CHOLERAE. It consists of two major protomers, the heavy (H) or A subunit and the B protomer which consists of 5 light (L) or B subunits. The catalytic A subunit is proteolytically cleaved into fragments A1 and A2. The A1 fragment is a MONO(ADP-RIBOSE) TRANSFERASE. The B protomer binds cholera toxin to intestinal epithelial cells, and facilitates the uptake of the A1 fragment. The A1 catalyzed transfer of ADP-RIBOSE to the alpha subunits of heterotrimeric G PROTEINS activates the production of CYCLIC AMP. Increased levels of cyclic AMP are thought to modulate release of fluid and electrolytes from intestinal crypt cells.

Cholera Toxin Protomer A [M0004247]
The catalytic subunit of cholera toxin. It is proteolytically cleaved into fragments A1 and A2. The A1 fragment is a MONO(ADP-RIBOSE) TRANSFERASE.

Choleragenoid [M0004246]
The nontoxic, pentameric B protomer of cholera toxin. The cell membrane binding component of cholera toxin.

Cholestenone 5 alpha-Reductase [M0072874]
An oxidoreductase that catalyzes the conversion of compounds that contain 5-alpha-cholestan-3-one into the cholest-4-en-3-one derivative. It plays an important role in the conversion of TESTOSTERONE into DIHYDROTESTOSTERONE and PROGESTERONE into DIHYDROPROGESTERONE.

Cholesterol 7-alpha-Hydroxylase [M0004276]
A membrane-bound cytochrome P450 enzyme that catalyzes the 7-alpha-hydroxylation of CHOLESTEROL in the presence of molecular oxygen and NADPH-FERRIHEMOPROTEIN REDUCTASE. This enzyme, encoded by CYP7, converts cholesterol to 7-alpha-hydroxycholesterol which is the first and rate-limiting step in the synthesis of BILE ACIDS.

Cholesterol Ester Transfer Proteins [M0067633]
Proteins that bind to and transfer CHOLESTEROL ESTERS between LIPOPROTEINS such as LOW-DENSITY LIPOPROTEINS and HIGH-DENSITY LIPOPROTEINS.

Cholesterol Esterase [M0004273]
An enzyme that catalyzes the hydrolysis of cholesterol and some other sterol esters, to liberate cholesterol plus a fatty acid anion.

Cholesterol Oxidase [M0004275]
An enzyme that catalyzes the oxidation of cholesterol in the presence of molecular oxygen to 4-cholesten-3-one and hydrogen peroxide. The enzyme is not specific for cholesterol, but will also oxidize other 3-hydroxysteroids. EC 1.1.3.6.

Cholesterol Side-Chain Cleavage Enzyme [M0004271]
A mitochondrial cytochrome P450 enzyme that catalyzes the side-chain cleavage of C27 cholesterol to C21 pregnenolone in the presence of molecular oxygen and NADPH-FERRIHEMOPROTEIN REDUCTASE. This enzyme, encoded by CYP11A1 gene, catalyzes the breakage between C20 and C22 which is the initial and rate-limiting step in the biosynthesis of various gonadal and adrenal steroid hormones.

Choline Dehydrogenase [M0072880]
An enzyme bound to the inner mitochondrial membrane that catalyzes the oxidation of CHOLINE to BETAINE.

Choline Kinase [M0004291]
An enzyme that is active in the first step of choline phosphoglyceride (lecithin) biosynthesis by catalyzing the phosphorylation of choline to phosphorylcholine in the presence of ATP. Ethanolamine and its methyl and ethyl derivatives can also act as acceptors. EC 2.7.1.32.

Choline O-Acetyltransferase [M0004289]
An enzyme that catalyzes the formation of acetylcholine from acetyl-CoA and choline. EC 2.3.1.6.

Choline-Phosphate Cytidylyltransferase [M0029591]
An enzyme that catalyzes the transfer of cytidylate (CMP) to choline phosphate to form CDPcholine. It is the rate-limiting enzyme in the choline pathway for the biosynthesis of phosphatidylcholine. Its activity is increased by glucocorticoids. EC 2.7.7.15.

Cholinesterases [M0004302]

Chondro-4-Sulfatase [M0004303]
An enzyme from the sulfuric ester hydrolase class that breaks down one of the products of the chondroitin lyase II reaction. EC 3.1.6.9.

Chondroitin ABC Lyase [M0029328]
An enzyme that catalyzes the eliminative degradation of polysaccharides containing 1,4-beta-D-hexosaminyl and 1,3-beta-D-glucuronosyl or 1,3-alpha-L-iduronosyl linkages to disaccharides containing 4-deoxy-beta-D-gluc-4-enuronosyl groups. (Enzyme Nomenclature, 1992) EC 4.2.2.4.

Chondroitin B Lyase [M0004311]

Chondroitin Eliminase [M0004312]

Chondroitin Lyases [M0004313]
Enzymes which catalyze the elimination of delta-4,5-D-glucuronate residues from polysaccharides containing 1,4-beta-hexosaminyl and 1,3-beta-D-glucuronosyl or 1,3-alpha-L-iduronosyl linkages thereby bringing about depolymerization. EC 4.2.2.4 acts on chondroitin sulfate A and C as well as on dermatan sulfate and slowly on hyaluronate. EC 4.2.2.5 acts on chondroitin sulfate A and C.

Chondroitin Sulfate Lyase [M0004314]

Chondroitin Sulfate Proteoglycan [M0017895]

Chondroitin Sulphate E Proteoglycan [M0017892]

Chondroitin-4-Sulfate Depolymerase [M0004323]

Chondroitinase-AC II [M0004315]

Chondroitinases [M0004325]

Chondroitinases and Chondroitin Lyases [M0004324]
Enzymes which catalyze the elimination of glucuronate residues from chondroitin A,B, and C or which catalyze the hydrolysis of sulfate groups of the 2-acetamido-2-deoxy-D-galactose 6-sulfate units of chondroitin sulfate. EC 4.2.2.-.

Chondroitinsulfatases [M0004326]
A group of enzymes that catalyze the hydrolysis of various sulfate bonds of chondroitin sulfate. EC 3.1.6.-.

Choriogonin [M0009542]

Chorionic Gonadotropin [M0009545]
A gonadotropic glycoprotein hormone produced primarily by the PLACENTA. Similar to the pituitary LUTEINIZING HORMONE in structure and function, chorionic gonadotropin is involved in maintaining the CORPUS LUTEUM during pregnancy. CG consists of two noncovalently linked subunits, alpha and beta. Within a species, the alpha subunit is virtually identical to the three pituitary glycoprotein hormones (TSH, LH, and FSH), but the beta subunit is unique and confers its biological specificity (CHORIONIC GONADOTROPIN, BETA SUBUNIT, HUMAN).

Chorionic Gonadotropin, beta Subunit, Human [M0028371]
The beta subunit of human CHORIONIC GONADOTROPIN. Its structure is similar to the beta subunit of LUTEINIZING HORMONE, except for the additional 30 amino acids at the carboxy end with the associated carbohydrate residues. HCG-beta is used as a diagnostic marker for early detection of pregnancy, spontaneous abortion (ABORTION, SPONTANEOUS); ECTOPIC PREGNANCY; HYDATIDIFORM MOLE; CHORIOCARCINOMA; or DOWN SYNDROME.

Chorionic Gonadotropin, Human [M0411989]

Chorismate Mutase [M0004343]
An isomerase that catalyzes the conversion of chorismic acid to prephenic acid. EC 5.4.99.5.

Chorismate Mutase-Prephenate Dehydratase [M0017551]

Chorismate Mutase-Prephenate Dehydrogenase [M0017553]

Chorulon [M0009543]

Chromatin [M0004370]
The material of CHROMOSOMES. It is a complex of DNA; HISTONES; and nonhistone proteins (CHROMOSOMAL PROTEINS, NON-HISTONE) found within the nucleus of a cell.

Chromobindins [M0140208]

Chromogranin A [M0492852]
A type of chromogranin which was first isolated from CHROMAFFIN CELLS of the ADRENAL MEDULLA but is also found in other tissues and in many species including human, bovine, rat, mouse, and others. It is an acidic protein with 431 to 445 amino acid residues. It contains fragments that inhibit vasoconstriction or release of hormones and neurotransmitter, while other fragments exert antimicrobial actions.

Chromogranin B [M0136113]
A type of chromogranin which was initially characterized in a rat PHEOCHROMOCYTOMA CELL LINE. It is found in many species including human, rat, mouse, and others. It is an acidic protein with 626 to 657 amino acid residues. In some species, it inhibits secretion of PARATHYROID HORMONE or INSULIN and exerts bacteriolytic effects in others.

Chromogranins [M0004395]
A group of acidic proteins that are major components of SECRETORY GRANULES in the endocrine and neuroendocrine cells. They play important roles in the aggregation, packaging, sorting, and processing of secretory protein prior to secretion. They are cleaved to release biologically active peptides. There are various types of granins, usually classified by their sources.

Chromosomal Proteins, Non-Histone [M0004403]
Nucleoproteins, which in contrast to HISTONES, are acid insoluble. They are involved in chromosomal functions; e.g. they bind selectively to DNA, stimulate transcription resulting in tissue-specific RNA synthesis and undergo specific changes in response to various hormones or phytomitogens.

Chylomicron Remnants [M0365537]
Metabolic products of chylomicron particles in which TRIGLYCERIDES have been selectively removed by the LIPOPROTEIN LIPASE. These remnants carry dietary lipids in the blood and are cholesterol-rich. Their interactions with MACROPHAGES; ENDOTHELIAL CELLS; and SMOOTH MUSCLE CELLS in the artery wall can lead to ATHEROSCLEROSIS.

Chylomicrons [M0004455]
A class of lipoproteins that carry dietary CHOLESTEROL and TRIGLYCERIDES from the SMALL INTESTINE to the tissues. Their density (0.93-1.006 g/ml) is the same as that of VERY-LOW-DENSITY LIPOPROTEINS.

Chymases [M0127894]
A family of neutral serine proteases with CHYMOTRYPSIN-like activity. Chymases are primarily found in the SECRETORY GRANULES of MAST CELLS and are released during mast cell degranulation.

Chymodiactin [M0333216]

Chymopapain [M0004458]
A cysteine endopeptidase isolated from papaya latex. Preferential cleavage at glutamic and aspartic acid residues. EC 3.4.22.6.

Chymopapain A [M0004459]

Chymopapain B [M0004460]

Chymosin [M0018781]
The predominant milk-clotting enzyme from the true stomach or abomasum of the suckling calf. It is secreted as an inactive precursor called prorennin and converted in the acid environment of the stomach to the active enzyme. EC 3.4.23.4.

Chymosin A [M0018779]

Chymosin C [M0018780]

Chymotrypsin [M0004462]
A serine endopeptidase secreted by the pancreas as its zymogen, CHYMOTRYPSINOGEN and carried in the pancreatic juice to the duodenum where it is activated by TRYPSIN. It selectively cleaves aromatic amino acids on the carboxyl side.

Chymotrypsinogen [M0004468]

Chymotrypsinogen A [M0004469]

Chymotrypsinogen beta [M0004470]

Ciliary Neurotrophic Factor [M0328175]
A neurotrophic factor that promotes the survival of various neuronal cell types and may play an important role in the injury response in the nervous system.

Ciliary Neurotrophic Factor Receptor alpha Subunit [M0332221]
A ciliary neurotrophic factor receptor subunit. It is anchored to the cell surface via GLYCOSYLPHOSPHATIDYLINOSITOL LINKAGE and has specificity for binding to CILIARY NEUROTROPHIC FACTOR. It lacks signal transducing domains which are found on the other two subunits of the receptor.

CIP-KIP Cyclin-Dependent Kinase Inhibitors [M0477621]

cis-4-Hydroxyproline [M0010777]

cis-trans-Isomerases [M0029312]
Enzymes that catalyze the rearrangement of geometry about double bonds. EC 5.2.

Citrate (si)-Synthase [M0004514]
Enzyme that catalyzes the first step of the tricarboxylic acid cycle (CITRIC ACID CYCLE). It catalyzes the reaction of oxaloacetate and acetyl CoA to form citrate and coenzyme A. This enzyme was formerly listed as EC 4.1.3.7.

Citrulline [M0004523]

CL-118532 [M0337462]

Class 1 Semaphorins [M0209551]
Transmembrane proteins involved in axonal guidance of peripheral neurons in the developing CNS of invertebrates. Semaphorin-1 refers to the class of SEMAPHORINS with an extracellular sema domain and a short cytoplasmic domain. Sema-1 was first identified in grasshopper as fasciclin IV, and has since been described in Drosophila and C. elegans. Two distinct members of this class of semaphorins exist: SEMA-1a (the original sema-1) and SEMA-1b, a homologous protein isolated from Drosophila which may be more important for neuronal differentiation than migration.

Class 2 Semaphorins [M0421692]

Class 3 Semaphorins [M0421693]

Class 4 Semaphorins [M0421694]

Class 5 Semaphorins [M0421695]

Class 6 Semaphorins [M0421729]

Class 7 Semaphorins [M0421730]

Class V Semaphorins [M0421731]

Clathrin [M0004541]
The main structural coat protein of COATED VESICLES which play a key role in the intracellular transport between membranous organelles. Each molecule of clathrin consists of three light chains (CLATHRIN LIGHT CHAINS) and three heavy chains (CLATHRIN HEAVY CHAINS) that form a structure called a triskelion. Clathrin also interacts with cytoskeletal proteins.

Clathrin Adaptors [M0404724]

Clathrin Assembly Protein Complex alpha Subunit [M0404743]

Clathrin Assembly Protein Complex beta Subunits [M0404744]

Clathrin Assembly Protein Complex delta Subunits [M0404763]

Clathrin Assembly Protein Complex gamma Subunits [M0404764]

Clathrin Assembly Protein Complex mu Subunits [M0404765]

Clathrin Assembly Protein Complex sigma Subunits [M0404773]

Clathrin Assembly Protein Complexes [M0404565]

Clathrin Assembly Protein Subunits [M0404775]

Clathrin Heavy Chains [M0266224]
The heavy chain subunits of clathrin.

Clathrin Light Chains [M0404383]
The light chain subunits of clathrin.

Claversal [M0029391]

Cleavage And Polyadenylation Specificity Factor [M0418575]
An RNA-binding protein that recognizes the AAUAAA RNA SEQUENCE at the 3' end of MRNA. It contains four subunits of 30, 73, 100 and 160 kDa molecular size and combines with CLEAVAGE STIMULATION FACTOR to form a stable complex with mRNA that directs the 3' cleavage and polyadenylation reaction.

Cleavage And Polyadenylation Specificity Factor, 100-kDa Subunit [M0418590]

Cleavage And Polyadenylation Specificity Factor, 160-kDa Subunit [M0418591]

Cleavage And Polyadenylation Specificity Factor, 30-kDa Subunit [M0195396]

Cleavage And Polyadenylation Specificity Factor, 73-kDa Subunit [M0418589]

Cleavage Stimulation Factor [M0195405]
A RNA-binding protein that stimulates the cleavage of the 3' end of MRNA near the POLYADENYLATION site. It is a heterotrimer of 55-, 64- and 77-kDa subunits and combines with CLEAVAGE STIMULATION FACTOR to form a stable complex with mRNA that directs the 3' cleavage and polyadenylation reaction.

Cloacin [M0004575]
A bacteriocin produced by a plasmid that can occur in several bacterial strains. It is a basic protein of molecular weight 56,000 and exists in a complex with its immunity protein which protects the host bacterium from its effects.

Cloacin Complex [M0004576]

Cloacin-Immunity Protein Complex [M0004577]

Clofen [M0454551]

Clorgyline-Resistant Amine Oxidase [M0002390]

Clupeine [M0004651]

Clusterin [M0082230]
A highly conserved heterodimeric glycoprotein that is differentially expressed during many severe physiological disturbance states such as CANCER; APOPTOSIS; and various NEUROLOGICAL DISORDERS. Clusterin is ubiquitously expressed and appears to function as a secreted MOLECULAR CHAPERONE.

CNP-53 [M0029832]

Co(II)-Aspartate Transcarbamoylase [M0001828]

Coagulase [M0004656]
Enzymes that cause coagulation in plasma by forming a complex with human PROTHROMBIN. Coagulases are produced by certain STAPHYLOCOCCUS and YERSINIA PESTIS. Staphylococci produce two types of coagulase: Staphylocoagulase, a free coagulase that produces true clotting of plasma, and Staphylococcal clumping factor, a bound coagulase in the cell wall that induces clumping of cells in the presence of fibrinogen.

Coat Protein Complex I [M0328620]
A protein complex comprised of COATOMER PROTEIN and ADP RIBOSYLATION FACTOR 1. It is involved in transport of vesicles between the ENDOPLASMIC RETICULUM and the GOLGI APPARATUS.

Coatomer alpha Subunit [M0331702]

Coatomer beta Subunit [M0331704]

Coatomer delta Subunit [M0331705]

Coatomer epsilon Subunit [M0331706]

Coatomer gamma Subunit [M0331708]

Coatomer Protein [M0328488]
A 700-kDa cytosolic protein complex consisting of seven equimolar subunits (alpha, beta, beta', gamma, delta, epsilon and zeta). COATOMER PROTEIN and ADP-RIBOSYLATION FACTOR 1 are principle components of COAT PROTEIN COMPLEX I and are involved in vesicle transport between the ENDOPLASMIC RETICULUM and the GOLGI APPARATUS.

Coatomer zeta Subunit [M0331707]

Cobalophilin [M0021776]

Cobalt Enolase [M0016708]

Cobalt Superoxide Dismutase [M0020826]

Cod�tricine [M0477139]

Codotussyl [M0445989]

Coenzyme A Ligases [M0004713]
Enzymes that catalyze the formation of acyl-CoA derivatives. EC 6.2.1.

Coenzyme A-Transferases [M0023496]
Enzymes which transfer coenzyme A moieties from acyl- or acetyl-CoA to various carboxylic acceptors forming a thiol ester. Enzymes in this group are instrumental in ketone body metabolism and utilization of acetoacetate in mitochondria. EC 2.8.3.

Cofilin 1 [M0480172]
Cofilin 1 is a member of the cofilin family of proteins that is expressed in non-muscle CELLS. It has ACTIN depolymerization activity that is dependent on HYDROGEN-ION CONCENTRATION.

Cofilin 2 [M0394534]
A member of the cofilin family of proteins that is expressed in MUSCLE CELLS. It has ACTIN depolymerization activity that is dependent on HYDROGEN-ION CONCENTRATION.

Colestipol Hydrochloride [M0423709]

Colicin A [M0004744]

Colicin B [M0004745]

Colicin E1 [M0004746]

Colicin E2 [M0004747]

Colicin E3 [M0004748]

Colicin E8 [M0004759]

Colicin HSC10 [M0004749]

Colicin Ia [M0004750]

Colicin Ib [M0004751]

Colicin K [M0004752]

Colicin K-K235 [M0004753]

Colicin M [M0004754]

Colicin N [M0004755]

Colicin V [M0004756]

Colicins [M0004757]
Bacteriocins elaborated by strains of Escherichia coli and related species. They are proteins or protein-lipopolysaccharide complexes lethal to other strains of the same species.

Colicins E [M0004758]

Colicins E9 [M0004760]

Colipase A [M0004763]

Colipase B [M0004764]

Colipases [M0004765]
Colipase I and II, consisting of 94-95 and 84-85 amino acid residues, respectively, have been isolated from porcine pancreas. Their role is to prevent the inhibitory effect of bile salts on the lipase-catalyzed intraduodenal hydrolysis of dietary long-chain triglycerides.

Colistin [M0004767]
Cyclic polypeptide antibiotic from Bacillus colistinus. It is composed of Polymyxins E1 and E2 (or Colistins A, B, and C) which act as detergents on cell membranes. Colistin is less toxic than Polymyxin B, but otherwise similar; the methanesulfonate is used orally.

Colistin Sulfate [M0004768]

Colistin Sulfomethate [M0004769]

Collagen [M0004775]
A polypeptide substance comprising about one third of the total protein in mammalian organisms. It is the main constituent of SKIN; CONNECTIVE TISSUE; and the organic substance of bones (BONE AND BONES) and teeth (TOOTH).

Collagen Felt [M0004776]

Collagen Fleece [M0004786]

Collagen Type I [M0004788]
The most common form of fibrillar collagen. It is a major constituent of bone (BONE AND BONES) and SKIN and consists of a heterotrimer of two alpha1(I) and one alpha2(I) chains.

Collagen Type I, alpha1 Subunit [M0369293]

Collagen Type I, alpha2 Subunit [M0004773]

Collagen Type II [M0004777]
A fibrillar collagen found predominantly in CARTILAGE and vitreous humor. It consists of three identical alpha1(II) chains.

Collagen Type II, alpha1 Subunit [M0369296]

Collagen Type III [M0004778]
A fibrillar collagen consisting of three identical alpha1(III) chains that is widely distributed in many tissues containing COLLAGEN TYPE I. It is particularly abundant in BLOOD VESSELS and may play a role in tissues with elastic characteristics.

Collagen Type III, alpha1 Chain [M0369299]

Collagen Type IV [M0004779]
A non-fibrillar collagen found in the structure of BASEMENT MEMBRANE. Collagen type IV molecules assemble to form a sheet-like network which is involved in maintaining the structural integrity of basement membranes. The predominant form of the protein is comprised of two alpha1(IV) subunits and one alpha2(IV) subunit, however, at least six different alpha subunits can be incorporated into the heterotrimer.

Collagen Type IV, alpha1 Subunit [M0369423]

Collagen Type IV, alpha2 Subunit [M0369424]

Collagen Type IX [M0004780]
A fibril-associated collagen usually found crosslinked to the surface of COLLAGEN TYPE II fibrils. It is a heterotrimer containing alpha1(IX), alpha2(IX) and alpha3(IX) subunits.

Collagen Type IX, alpha1 Subunit [M0369330]

Collagen Type IX, alpha2 Subunit [M0369331]

Collagen Type IX, alpha3 Subunit [M0369332]

Collagen Type V [M0004781]
A fibrillar collagen found widely distributed as a minor component in tissues that contain COLLAGEN TYPE I and COLLAGEN TYPE III. It is a heterotrimeric molecule composed of alpha1(V), alpha2(V) and alpha3(V) subunits. Several forms of collagen type V exist depending upon the composition of the subunits that form the trimer.

Collagen Type V, alpha1 Subunit [M0369301]

Collagen Type V, alpha2 Subunit [M0370197]

Collagen Type V, alpha3 Subunit [M0370198]

Collagen Type VI [M0004782]
A non-fibrillar collagen that forms a network of MICROFIBRILS within the EXTRACELLULAR MATRIX of CONNECTIVE TISSUE. The alpha subunits of collagen type VI assemble into antiparallel, overlapping dimers which then align to form tetramers.

Collagen Type VI, alpha1 Subunit [M0369433]

Collagen Type VI, alpha2 Subunit [M0369434]

Collagen Type VI, alpha3 Subunit [M0369435]

Collagen Type VII [M0004783]
A non-fibrillar collagen involved in anchoring the epidermal BASEMENT MEMBRANE to underlying tissue. It is a homotrimer comprised of C-terminal and N-terminal globular domains connected by a central triple-helical region.

Collagen Type VII, alpha1 Subunit [M0369443]

Collagen Type VIII [M0004784]
A non-fibrillar collagen originally found in DESCEMET MEMBRANE. It is expressed in endothelial cell layers and in tissues undergoing active remodeling. It is heterotrimer comprised of alpha1(VIII) and alpha2(VIII) chains.

Collagen Type X [M0004785]
A non-fibrillar collagen found primarily in terminally differentiated hypertrophic CHONDROCYTES. It is a homotrimer of three identical alpha1(X) subunits.

Collagen Type X, alpha1 Subunit [M0369412]

Collagen Type XI [M0004789]
A fibrillar collagen found primarily in interstitial CARTILAGE. Collagen type XI is heterotrimer containing alpha1(XI), alpha2(XI) and alpha3(XI) subunits.

Collagen Type XI, alpha1 Subunit [M0369487]

Collagen Type XI, alpha2 Subunit [M0369488]

Collagen Type XI, alpha3 Subunit [M0369489]

Collagen Type XII [M0004790]
A fibril-associated collagen found in many tissues bearing high tensile stress, such as TENDONS and LIGAMENTS. It is comprised of a trimer of three identical alpha1(XII) chains.

Collagen Type XII, alpha1 Subunit [M0369372]

Collagen Type XIII [M0004791]
A non-fibrillar collagen found as a ubiquitously expressed membrane- associated protein. Type XIII collagen contains both collagenous and non-collagenous domains along with a transmembrane domain within its N-terminal region.

Collagen Type XIII, alpha1 Subunit [M0369516]

Collagen Type XVIII [M0442508]
A non-fibrillar collagen found in BASEMENT MEMBRANE. The C-terminal end of the alpha1 chain of collagen type XVIII contains the ENDOSTATIN peptide, which can be released by proteolytic cleavage.

Collagen Type XVIII, alpha1 Subunit [M0227652]

Collagen Type-VIII, alpha1 Subunit [M0369413]

Collagenase Inhibitor [M0029269]

Collagenase-Like Peptidase [M0004634]

Collagenases [M0026363]
Enzymes that catalyze the degradation of collagen by acting on the peptide bonds. EC 3.4.24.-.

Collastat [M0369416]

Collectins [M0086742]
A class of C-type lectins that target the carbohydrate structures found on invading pathogens. Binding of collectins to microorganisms results in their agglutination and enhanced clearance. Collectins form trimers that may assemble into larger oligomers. Each collectin polypeptide chain consists of four regions: a relatively short N-terminal region, a collagen-like region, an alpha-helical coiled-coil region, and carbohydrate-binding region.

Colony-Stimulating Factors [M0004822]
Glycoproteins found in a subfraction of normal mammalian plasma and urine. They stimulate the proliferation of bone marrow cells in agar cultures and the formation of colonies of granulocytes and/or macrophages. The factors include INTERLEUKIN-3; (IL-3); GRANULOCYTE COLONY-STIMULATING FACTOR; (G-CSF); MACROPHAGE COLONY-STIMULATING FACTOR; (M-CSF); and GRANULOCYTE-MACROPHAGE COLONY-STIMULATING FACTOR; (GM-CSF).

Colony-Stimulating Factors, Recombinant [M0028829]
COLONY-STIMULATING FACTORS prepared by recombinant DNA technology.

Colostral IgA [M0011003]

Coly-Mycin [M0372333]

Complement Activating Enzymes [M0004917]
Enzymes that activate one or more COMPLEMENT PROTEINS in the complement system leading to the formation of the COMPLEMENT MEMBRANE ATTACK COMPLEX, an important response in host defense. They are enzymes in the various COMPLEMENT ACTIVATION pathways.

Complement C1 [M0004924]
The first complement component to act in the activation of CLASSICAL COMPLEMENT PATHWAY. It is a calcium-dependent trimolecular complex made up of three subcomponents: COMPLEMENT C1Q; COMPLEMENT C1R; and COMPLEMENT C1S at 1:2:2 ratios. When the intact C1 binds to at least two antibodies (involving C1q), C1r and C1s are sequentially activated, leading to subsequent steps in the cascade of COMPLEMENT ACTIVATION.

Complement C1 Inactivator Proteins [M0004926]
Serum proteins that inhibit, antagonize, or inactivate COMPLEMENT C1 or its subunits.

Complement C1 Inhibitor Protein [M0476632]
An endogenous serine protease inhibitor (SERPINS). It is a 105-kDA plasma glycoprotein, encoded by C1NH gene and produced primarily by the liver and monocytes. It inhibits a broad spectrum of proteases, including the COMPLEMENT C1R and the COMPLEMENT C1S proteases of the CLASSICAL COMPLEMENT PATHWAY, and the MANNOSE-BINDING PROTEIN-ASSOCIATED SERINE PROTEASES. C1-INH-deficient individuals suffer from hereditary ANGIONEUROTIC EDEMA.

Complement C1q [M0024366]
A subcomponent of complement C1, composed of six copies of three polypeptide chains (A, B, and C), each encoded by a separate gene (C1QA; C1QB; C1QC). This complex is arranged in nine subunits (six disulfide-linked dimers of A and B, and three disulfide-linked homodimers of C). C1q has binding sites for antibodies (the heavy chain of IMMUNOGLOBULIN G or IMMUNOGLOBULIN M). The interaction of C1q and immunoglobulin activates the two proenzymes COMPLEMENT C1R and COMPLEMENT C1S, thus initiating the cascade of COMPLEMENT ACTIVATION via the CLASSICAL COMPLEMENT PATHWAY.

Complement C1r [M0024367]
A 80-kDa subcomponent of complement C1, existing as a SERINE PROTEASE proenzyme in the intact complement C1 complex. When COMPLEMENT C1Q is bound to antibodies, the changed tertiary structure causes autolytic activation of complement C1r which is cleaved into two chains, A (heavy) and B (light, the serine protease), connected by disulfide bonds. The activated C1r serine protease, in turn, activates COMPLEMENT C1S proenzyme by cleaving the Arg426-Ile427 bond. No fragment is released when either C1r or C1s is cleaved.

Complement C1r Protease Inhibitor Proteins [M0476631]

Complement C1s [M0004925]
A 77-kDa subcomponent of complement C1, encoded by gene C1S, is a SERINE PROTEASE existing as a proenzyme (homodimer) in the intact complement C1 complex. Upon the binding of COMPLEMENT C1Q to antibodies, the activated COMPLEMENT C1R cleaves C1s into two chains, A (heavy) and B (light, the serine protease), linked by disulfide bonds yielding the active C1s. The activated C1s, in turn, cleaves COMPLEMENT C2 and COMPLEMENT C4 to form C4b2a (CLASSICAL C3 CONVERTASE).

Complement C1s Esterase Inhibitor Proteins [M0476630]

Complement C2 [M0004927]
A component of the CLASSICAL COMPLEMENT PATHWAY. C2 is cleaved by activated COMPLEMENT C1S into COMPLEMENT C2B and COMPLEMENT C2A. C2a, the COOH-terminal fragment containing a SERINE PROTEASE, combines with COMPLEMENT C4B to form C4b2a (CLASSICAL PATHWAY C3 CONVERTASE) and subsequent C4b2a3b (CLASSICAL PATHWAY C5 CONVERTASE).

Complement C2a [M0138655]
The COOH-terminal fragment of COMPLEMENT 2, released by the action of activated COMPLEMENT C1S. It is a SERINE PROTEASE. C2a combines with COMPLEMENT C4B to form C4b2a (CLASSICAL PATHWAY C3 CONVERTASE) and subsequent C4b2a3b (CLASSICAL PATHWAY C5 CONVERTASE).

Complement C2b [M0132802]
The N-terminal fragment of COMPLEMENT 2, released by the action of activated COMPLEMENT C1S.

Complement C3 [M0004928]
A glycoprotein that is central in both the classical and the alternative pathway of COMPLEMENT ACTIVATION. C3 can be cleaved into COMPLEMENT C3A and COMPLEMENT C3B, spontaneously at low level or by C3 CONVERTASE at high level. The smaller fragment C3a is an ANAPHYLATOXIN and mediator of local inflammatory process. The larger fragment C3b binds with C3 convertase to form C5 convertase.

Complement C3 Convertase, Alternative Pathway [M0476518]
A serine protease that is the complex of COMPLEMENT C3B and COMPLEMENT FACTOR BB. It cleaves multiple COMPLEMENT C3 into COMPLEMENT C3A (anaphylatoxin) and COMPLEMENT C3B in the ALTERNATIVE COMPLEMENT ACTIVATION PATHWAY.

Complement C3 Convertase, Classical Pathway [M0476526]
A serine protease that cleaves multiple COMPLEMENT 3 into COMPLEMENT 3A (anaphylatoxin) and COMPLEMENT 3B in the CLASSICAL COMPLEMENT ACTIVATION PATHWAY. It is a complex of COMPLEMENT 4B and COMPLEMENT 2A (C4b2a).

Complement C3 Convertase, CVFBb [M0481023]
Cobra venom factor (CVF) is a COMPLEMENT C3B analog. With Bb, CVF forms the CVFBb complex, a COMPLEMENT C3 convertase with a half-life of 7 h at body temperature as compared to 1.5 min for the C3bBb complex. The cobra venom-derived enzyme causes continuous COMPLEMENT ACTIVATION and depletion of downstream complement components.

Complement C3 Convertases [M0004929]
Serine proteases that cleaves C3 at the carboxyl of Arg-77 of the alpha-chain to yield COMPLEMENT 3A and COMPLEMENT 3B in either the classical or the alternative pathways of COMPLEMENT ACTIVATION.

Complement C3 Nephritic Factor [M0004930]
An IgG autoantibody against the ALTERNATIVE COMPLEMENT C3 CONVERTASE (C3bBb), found in serum of patients with MESANGIOCAPILLARY GLOMERULONEPHRITIS. The binding of this autoantibody to C3bBb stabilizes the enzyme thus reduces the actions of C3b inactivators (COMPLEMENT FACTOR H; COMPLEMENT FACTOR I). This abnormally stabilized enzyme induces a continuous COMPLEMENT ACTIVATION and generation of C3b thereby promoting the assembly of MEMBRANE ATTACK COMPLEX and cytolysis.

Complement C3 Precursor [M0102971]

Complement C3-C5 Convertases [M0476514]
Serine proteases that cleave COMPLEMENT C3 into COMPLEMENT C3A and COMPLEMENT C3B, or cleave COMPLEMENT C5 into COMPLEMENT C5A and COMPLEMENT C5B. These include the different forms of C3/C5 convertases in the classical and the alternative pathways of COMPLEMENT ACTIVATION. Both cleavages take place at the C-terminal of an ARGININE residue.

Complement C3-C5 Convertases, Alternative Pathway [M0476517]
Important enzymes in the ALTERNATIVE COMPLEMENT ACTIVATION PATHWAY. They cleave COMPLEMENT C3 and COMPLEMENT C5.

Complement C3-C5 Convertases, Classical Pathway [M0476525]
Important enzymes in the CLASSICAL COMPLEMENT ACTIVATION PATHWAY. They cleave COMPLEMENT C3 and COMPLEMENT C5.

Complement C3a [M0024371]
The smaller fragment generated from the cleavage of complement C3 by C3 CONVERTASE. C3a, a 77-amino acid peptide, is a mediator of local inflammatory process. It induces smooth MUSCLE CONTRACTION, and HISTAMINE RELEASE from MAST CELLS and LEUKOCYTES. C3a is considered an anaphylatoxin along with COMPLEMENT C4A; COMPLEMENT C5A; and COMPLEMENT C5A, DES-ARGININE.

Complement C3b [M0004932]
The larger fragment generated from the cleavage of COMPLEMENT C3 by C3 CONVERTASE. It is a constituent of the ALTERNATIVE PATHWAY C3 CONVERTASE (C3bBb), and COMPLEMENT C5 CONVERTASES in both the classical (C4b2a3b) and the alternative (C3bBb3b) pathway. C3b participates in IMMUNE ADHERENCE REACTION and enhances PHAGOCYTOSIS. It can be inactivated (iC3b) or cleaved by various proteases to yield fragments such as COMPLEMENT C3C; COMPLEMENT C3D; C3e; C3f; and C3g.

Complement C3b Inactivator Proteins [M0004933]
Endogenous proteins that inhibit or inactivate COMPLEMENT C3B. They include COMPLEMENT FACTOR H and COMPLEMENT FACTOR I (C3b/C4b inactivator). They cleave or promote the cleavage of C3b into inactive fragments, and thus are important in the down-regulation of COMPLEMENT ACTIVATION and its cytolytic sequence.

Complement C3c [M0024377]
A 206-amino-acid fragment in the alpha chain (672-1663) of C3b. It is generated when C3b is inactivated (iC3b) and its alpha chain is cleaved by COMPLEMENT FACTOR I into C3c (749-954), and C3dg (955-1303) in the presence COMPLEMENT FACTOR H.

Complement C3d [M0024378]
A 302-amino-acid fragment in the alpha chain (672-1663) of C3b. It is generated when C3b is inactivated (iC3b) and its alpha chain is cleaved by COMPLEMENT FACTOR I into C3c, and C3dg (955-1303) in the presence COMPLEMENT FACTOR H. Serum proteases further degrade C3dg into C3d (1002-1303) and C3g (955-1001).

Complement C4 [M0004934]
A glycoprotein that is important in the activation of CLASSICAL COMPLEMENT PATHWAY. C4 is cleaved by the activated COMPLEMENT C1S into COMPLEMENT C4A and COMPLEMENT C4B.

Complement C4, Precursor [M0086190]

Complement C4a [M0024379]
The smaller fragment formed when complement C4 is cleaved by COMPLEMENT C1S. It is an anaphylatoxin that causes symptoms of immediate hypersensitivity (HYPERSENSITIVITY, IMMEDIATE) but its activity is weaker than that of COMPLEMENT C3A or COMPLEMENT C5A.

Complement C4b [M0024380]
The large fragment formed when COMPLEMENT C4 is cleaved by COMPLEMENT C1S. The membrane-bound C4b binds COMPLEMENT C2A, a SERINE PROTEASE, to form C4b2a (CLASSICAL PATHWAY C3 CONVERTASE) and subsequent C4b2a3b (CLASSICAL PATHWAY C5 CONVERTASE).

Complement C4b-Binding Protein [M0096952]
A serum protein that regulates the CLASSICAL COMPLEMENT ACTIVATION PATHWAY. It binds as a cofactor to COMPLEMENT FACTOR I which then hydrolyzes the COMPLEMENT C4B in the CLASSICAL PATHWAY C3 CONVERTASE (C4bC2a).

Complement C5 [M0004937]
C5 plays a central role in both the classical and the alternative pathway of COMPLEMENT ACTIVATION. C5 is cleaved by C5 CONVERTASE into COMPLEMENT C5A and COMPLEMENT C5B. The smaller fragment C5a is an ANAPHYLATOXIN and mediator of inflammatory process. The major fragment C5b binds to the membrane initiating the spontaneous assembly of the late complement components, C5-C9, into the MEMBRANE ATTACK COMPLEX.

Complement C5 Convertase, Alternative Pathway [M0476519]
A serine protease that cleaves multiple COMPLEMENT C5 into COMPLEMENT C5A (anaphylatoxin) and COMPLEMENT C5B in the ALTERNATIVE COMPLEMENT ACTIVATION PATHWAY. It is the complex of ALTERNATIVE PATHWAY C3 CONVERTASE (C3bBb) with an additional COMPLEMENT C3B, or C3bBb3b.

Complement C5 Convertase, Classical Pathway [M0476527]
A serine protease that cleaves multiple COMPLEMENT 5 into COMPLEMENT 5A (anaphylatoxin) and COMPLEMENT 5B in the CLASSICAL COMPLEMENT ACTIVATION PATHWAY. It is a complex of CLASSICAL PATHWAY C3 CONVERTASE (C4b2a) with an additional COMPLEMENT C3B, or C4b2a3b.

Complement C5 Convertases [M0476516]
Serine proteases that cleaves C5 at the carboxyl of Arg-74 of the alpha-chain to yield COMPLEMENT 5A and COMPLEMENT 5B in either the classical or the alternative pathways of COMPLEMENT ACTIVATION.

Complement C5, Precursor [M0187443]

Complement C5a [M0024381]
The minor fragment formed when C5 convertase cleaves C5 into C5a and COMPLEMENT C5B. C5a is a 74-amino-acid glycopeptide with a carboxy-terminal ARGININE that is crucial for its spasmogenic activity. Of all the complement-derived anaphylatoxins, C5a is the most potent in mediating immediate hypersensitivity (HYPERSENSITIVITY, IMMEDIATE), smooth MUSCLE CONTRACTION; HISTAMINE RELEASE; and migration of LEUKOCYTES to site of INFLAMMATION.

Complement C5a, des-Arginine [M0024382]
A derivative of complement C5a, generated when the carboxy-terminal ARGININE is removed by CARBOXYPEPTIDASE B present in normal human serum. C5a des-Arg shows complete loss of spasmogenic activity though it retains some chemotactic ability (CHEMOATTRACTANTS).

Complement C5b [M0105345]
The larger fragment generated from the cleavage of C5 by C5 CONVERTASE that yields COMPLEMENT C5A and C5b (beta chain + alpha' chain, the residual alpha chain, bound by disulfide bond). C5b remains bound to the membrane and initiates the spontaneous assembly of the late complement components to form C5b-8-poly-C9, the MEMBRANE ATTACK COMPLEX.

Complement C6 [M0004938]
A 105-kDa serum glycoprotein with significant homology to the other late complement components, C7-C9. It is a polypeptide chain cross-linked by 32 disulfide bonds. C6 is the next complement component to bind to the membrane-bound COMPLEMENT C5B in the assembly of MEMBRANE ATTACK COMPLEX. It is encoded by gene C6.

Complement C7 [M0004939]
A 93-kDa serum glycoprotein encoded by C7 gene. It is a polypeptide chain with 28 disulfide bridges. In the formation of MEMBRANE ATTACK COMPLEX; C7 is the next component to bind the C5b-6 complex forming a trimolecular complex C5b-7 which is lipophilic, resembles an integral membrane protein, and serves as an anchor for the late complement components, C8 and C9.

Complement C8 [M0004940]
A 150-kDa serum glycoprotein composed of three subunits with each encoded by a different gene (C8A; C8B; and C8G). This heterotrimer contains a disulfide-linked C8alpha-C8gamma heterodimer and a noncovalently associated C8beta chain. C8 is the next component to bind the C5-7 complex forming C5b-8 that binds COMPLEMENT C9 and acts as a catalyst in the polymerization of C9.

Complement C9 [M0004941]
A 63-kDa serum glycoprotein encoded by gene C9. Monomeric C9 (mC9) binds the C5b-8 complex to form C5b-9 which catalyzes the polymerization of C9 forming C5b-p9 (MEMBRANE ATTACK COMPLEX) and transmembrane channels leading to lysis of the target cell. Patients with C9 deficiency suffer from recurrent bacterial infections.

Complement Component C8 alpha [M0477757]

Complement Component C8 beta [M0477758]

Complement Component C8 gamma [M0477759]

Complement Cytolysis Inhibiting Agents [M0476624]

Complement Cytolysis Inhibitor Proteins [M0479105]

Complement Factor B [M0017749]
A glycine-rich, heat-labile serum glycoprotein that contains a component of the ALTERNATIVE COMPLEMENT C3 CONVERTASE (C3bBb). Bb, a serine protease, is generated when factor B is cleaved by COMPLEMENT FACTOR D into Ba and Bb.

Complement Factor Ba [M0017750]

Complement Factor Bb [M0469165]

Complement Factor D [M0017753]
A serum protein which is important in the ALTERNATIVE COMPLEMENT ACTIVATION PATHWAY. This enzyme cleaves the COMPLEMENT C3B-bound COMPLEMENT FACTOR B to form C3bBb which is ALTERNATIVE PATHWAY C3 CONVERTASE.

Complement Factor H [M0026162]
An important soluble regulator of the alternative pathway of complement activation (COMPLEMENT ACTIVATION PATHWAY, ALTERNATIVE). It is a 139-kDa glycoprotein expressed by the liver and secreted into the blood. It binds to COMPLEMENT C3B and makes iC3b (inactivated complement 3b) susceptible to cleavage by COMPLEMENT FACTOR I. Complement factor H also inhibits the association of C3b with COMPLEMENT FACTOR B to form the C3bB proenzyme, and promotes the dissociation of Bb from the C3bBb complex (COMPLEMENT C3 CONVERTASE, ALTERNATIVE PATHWAY).

Complement Factor I [M0026165]
A plasma serine proteinase that cleaves the alpha-chains of C3b and C4b in the presence of the cofactors COMPLEMENT FACTOR H and C4-binding protein, respectively. It is a 66-kDa glycoprotein that converts C3b to inactivated C3b (iC3b) followed by the release of two fragments, C3c (150-kDa) and C3dg (41-kDa). It was formerly called KAF, C3bINF, or enzyme 3b inactivator.

Complement Inactivator Proteins [M0004921]
Serum proteins that negatively regulate the cascade process of COMPLEMENT ACTIVATION. Uncontrolled complement activation and resulting cell lysis is potentially dangerous for the host. The complement system is tightly regulated by inactivators that accelerate the decay of intermediates and certain cell surface receptors.

Complement Membrane Attack Complex [M0024383]
A product of COMPLEMENT ACTIVATION cascade, regardless of the pathways, that forms transmembrane channels causing disruption of the target CELL MEMBRANE and cell lysis. It is formed by the sequential assembly of terminal complement components (COMPLEMENT C5B; COMPLEMENT C6; COMPLEMENT C7; COMPLEMENT C8; and COMPLEMENT C9) into the target membrane. The resultant C5b-8-poly-C9 is the "membrane attack complex" or MAC.

Complement Receptor Type 1 [M0018567]

Complement System Proteins [M0004915]
Serum glycoproteins participating in the host defense mechanism of COMPLEMENT ACTIVATION that creates the COMPLEMENT MEMBRANE ATTACK COMPLEX. Included are glycoproteins in the various pathways of complement activation (CLASSICAL COMPLEMENT PATHWAY; ALTERNATIVE COMPLEMENT PATHWAY; and LECTIN COMPLEMENT PATHWAY).

Complementarity Determining Region 1 [M0359512]

Complementarity Determining Region 2 [M0359513]

Complementarity Determining Region 3 [M0359514]

Complementarity Determining Regions [M0359304]
Three regions (CDR1; CDR2 and CDR3) of amino acid sequence in the IMMUNOGLOBULIN VARIABLE REGION that are highly divergent. Together the CDRs from the light and heavy immunoglobulin chains form a surface that is complementary to the antigen. These regions are also present in other members of the immunoglobulin superfamily, for example, T-cell receptors (RECEPTORS, ANTIGEN, T-CELL).

Conalbumin [M0004981]
A glycoprotein albumin from hen's egg white with strong iron-binding affinity.

Concanavalin A [M0004982]
A MANNOSE/GLUCOSE binding lectin isolated from the jack bean (Canavalia ensiformis). It is a potent mitogen used to stimulate cell proliferation in lymphocytes, primarily T-lymphocyte, cultures.

Connexin 43 [M0027217]
A 43-kDa peptide which is a member of the connexin family of gap junction proteins. Connexin 43 is a product of a gene in the alpha class of connexin genes (the alpha-1 gene). It was first isolated from mammalian heart, but is widespread in the body including the brain.

Connexins [M0026696]
A group of homologous proteins which form the intermembrane channels of GAP JUNCTIONS. The connexins are the products of an identified gene family which has both highly conserved and highly divergent regions. The variety contributes to the wide range of functional properties of gap junctions.

Conotoxins [M0328109]
Peptide neurotoxins from the marine fish-hunting snails of the genus CONUS. They contain 13 to 29 amino acids which are strongly basic and are highly cross-linked by disulfide bonds. There are three types of conotoxins, omega-, alpha-, and mu-. OMEGA-CONOTOXINS inhibit voltage-activated entry of calcium into the presynaptic membrane and therefore the release of ACETYLCHOLINE. Alpha-conotoxins inhibit the postsynaptic acetylcholine receptor. Mu-conotoxins prevent the generation of muscle action potentials. (From Concise Encyclopedia Biochemistry and Molecular Biology, 3rd ed)

Contractile Proteins [M0005127]
Proteins which participate in contractile processes. They include MUSCLE PROTEINS as well as those found in other cells and tissues. In the latter, these proteins participate in localized contractile events in the cytoplasm, in motile activity, and in cell aggregation phenomena.

Contrykal [M0011909]

Copper Cystinate [M0005554]

Copper Penicillaminate [M0016120]

Coproporphyrinogen Oxidase [M0005157]
An enzyme that catalyzes the oxidative decarboxylation of coproporphyrinogen III to protoporphyrinogen IX by the conversion of two propionate groups to two vinyl groups. It is the sixth enzyme in the 8-enzyme biosynthetic pathway of HEME, and is encoded by CPO gene. Mutations of CPO gene result in HEREDITARY COPROPORPHYRIA.

Cordilox [M0022605]

Core Binding Factor Alpha 1 Subunit [M0276678]
A transcription factor that dimerizes with CORE BINDING FACTOR BETA SUBUNIT to form core binding factor. It contains a highly conserved DNA-binding domain known as the runt domain and is involved in genetic regulation of skeletal development and CELL DIFFERENTIATION.

Core Binding Factor Alpha 2 Subunit [M0215816]
A transcription factor that dimerizes with the cofactor CORE BINDING FACTOR BETA SUBUNIT to form core binding factor. It contains a highly conserved DNA-binding domain known as the runt domain. Runx1 is frequently mutated in human LEUKEMIAS.

Core Binding Factor Alpha 3 Subunit [M0399600]
A transcription factor that dimerizes with the cofactor CORE BINDING FACTOR BETA SUBUNIT to form core binding factor. It contains a highly conserved DNA-binding domain known as the runt domain.

Core Binding Factor alpha Subunits [M0151835]
A family of transcription factors that bind to the cofactor CORE BINDING FACTOR BETA SUBUNIT to form core binding factor. Family members contain a highly conserved DNA-binding domain known as the runt domain. They can act as both activators and repressors of expression of GENES involved in CELL DIFFERENTIATION and CELL CYCLE progression.

Core Binding Factor beta Subunit [M0477050]
A non-DNA binding transcription factor that is a subunit of core binding factor. It forms heterodimeric complexes with CORE BINDING FACTOR ALPHA SUBUNITS, and regulates GENETIC TRANSCRIPTION of a variety of GENES involved primarily in CELL DIFFERENTIATION and CELL CYCLE progression.

Core Binding Factors [M0211900]
Heterodimeric transcription factors containing a DNA-binding alpha subunits, (CORE BINDING FACTOR ALPHA SUBUNITS), along with a non-DNA-binding beta subunits, CORE BINDING FACTOR BETA SUBUNIT. Core Binding Factor regulates GENETIC TRANSCRIPTION of a variety of GENES involved primarily in CELL DIFFERENTIATION and CELL CYCLE progression.

Core I Protein, Ubiquinol-Cytochrome c Reductase [M0190307]

Core II Protein, Ubiquinol-Cytochrome c Reductase [M0190309]

Core Protein lambda 2 [M0022697]

Core Protein V [M0022698]

Corona Virus Membrane Protein E1 [M0022708]

Coronavirus gpE1 [M0022709]

Coronavirus Peplomer Protein E1 [M0022710]

Coronavirus Peplomer Protein E2 JHM [M0022711]

Cortactin [M0214241]
A microfilament protein that interacts with F-ACTIN and regulates cortical actin assembly and organization. It is also an SH3 DOMAIN containing phosphoprotein, and it mediates tyrosine PHOSPHORYLATION based SIGNAL TRANSDUCTION by PROTO-ONCOGENE PROTEIN PP60(C-SRC).

Corticosteroid-Anionbinder IIIA [M0021785]

Corticotropin-Like Intermediate Lobe Peptide [M0066247]
A peptide derived from the cleavage of ADRENOCORTICOTROPIC HORMONE, found primarily in the INTERMEDIATE LOBE OF PITUITARY but also in the ARCUATE NUCLEUS of basal HYPOTHALAMUS. Its sequence is identical to the C-terminal 22-amino acids of ACTH or ACTH 18-39.

Corticotropin-Releasing Hormone [M0005218]
A peptide of about 41 amino acids that stimulates the release of ADRENOCORTICOTROPIC HORMONE. CRH is synthesized by neurons in the PARAVENTRICULAR NUCLEUS of the HYPOTHALAMUS. After being released into the pituitary portal circulation, CRH stimulates the release of ACTH from the PITUITARY GLAND. CRH can also be synthesized in other tissues, such as PLACENTA; ADRENAL MEDULLA; and TESTIS.

Cortisone Reductase [M0005221]
An enzyme that catalyzes the interconversion of a ketone and hydroxy group at C-20 of cortisone and other 17,20,21-trihydroxy steroids. EC 1.1.1.53.

Cortosyn [M0372335]

Cortrosyn [M0372334]

Cosmegen [M0354002]

Cosyntropin [M0005246]
A synthetic peptide that is identical to the 24-amino acid segment at the N-terminal of ADRENOCORTICOTROPIC HORMONE. ACTH (1-24), a segment similar in all species, contains the biological activity that stimulates production of CORTICOSTEROIDS in the ADRENAL CORTEX.

Cotazym-S [M0474885]

Cotazyme [M0045745]

COUP Transcription Factor I [M0162933]
A COUP transcription factor that was originally identified as a homodimer that binds to a direct repeat regulatory element in the chicken albumin PROMOTOR. It is a transcription factor that plays an important role in EMBRYONIC DEVELOPMENT of the CENTRAL NERVOUS SYSTEM.

COUP Transcription Factor II [M0184000]
A COUP transcription factor that plays a role as a negative regulator of GENETIC TRANSCRIPTION that competes with other hormone receptors for the common response element AGGTCA. It can also stimulate transcription of genes involved in the METABOLISM of GLUCOSE and CHOLESTEROL.

COUP Transcription Factors [M0373129]
A sub-family of steroid receptor transcription factors with specificity for a variety of DNA sequences related to AGGTCA. They can heterodimerize with a variety of factors including RETINOIC ACID RECEPTORS; THYROID HORMONE RECEPTORS; and VITAMIN D RECEPTORS.

CP-10,188 [M0363633]

CRADD Signaling Adaptor Protein [M0492988]
A death domain receptor signaling adaptor protein that plays a role in signaling the activation of INITIATOR CASPASES such as CASPASE 2. It contains a death domain that is specific for RIP SERINE THEONINE KINASES and a caspase-binding domain that binds to and activates CASPASES such as CASPASE 2.

Crasnitin [M0434510]

Creatine [M0005292]
An amino acid that occurs in vertebrate tissues and in urine. In muscle tissue, creatine generally occurs as phosphocreatine. Creatine is excreted as CREATININE in the urine.

Creatine Kinase [M0005293]
A transferase that catalyzes formation of PHOSPHOCREATINE from ATP + CREATINE. The reaction stores ATP energy as phosphocreatine. Three cytoplasmic ISOENZYMES have been identified in human tissues: the MM type from SKELETAL MUSCLE, the MB type from myocardial tissue and the BB type from nervous tissue as well as a mitochondrial isoenzyme. Macro-creatine kinase refers to creatine kinase complexed with other serum proteins.

Creatine Kinase, BB Form [M0005296]
A form of creatine kinase found in the BRAIN.

Creatine Kinase, MB Form [M0005297]
An isoenzyme of creatine kinase found in the CARDIAC MUSCLE.

Creatine Kinase, Mitochondrial Form [M0363590]
A form of creatine kinase found in the MITOCHONDRIA.

Creatine Kinase, MM Form [M0005298]
An isoenzyme of creatine kinase found in the MUSCLE.

CREB-Binding Protein [M0232674]
A member of the p300-CBP transcription factor family that was initially identified as a binding partner for CAMP RESPONSE ELEMENT-BINDING PROTEIN. Mutations in CREB-binding protein are associated with RUBINSTEIN-TAYBI SYNDROME.

CREM Protein, alpha Isoform [M0325109]

CREM Protein, epsilon Isoform [M0185186]

CREM Protein, gamma Isoform [M0325108]

CREM Protein, tau Isoform [M0475655]

Creon [M0045744]

Crk-Associated Substrate Protein [M0477396]
Crk-associated substrate was originally identified as a highly phosphorylated 130 kDa protein that associates with ONCOGENE PROTEIN CRK and ONCOGENE PROTEIN SRC. It is a signal transducing adaptor protein that undergoes tyrosine PHOSPHORYLATION in signaling pathways that regulate CELL MIGRATION and CELL PROLIFERATION.

Crosseal [M0464875]
A human plasma-derived fibrin sealant that rapidly forms a clot.

Cryo-Tropin [M0475573]

Cryoglobulins [M0005377]
Abnormal immunoglobulins, especially IGG or IGM, that precipitate spontaneously when SERUM is cooled below 37 degrees Celsius. It is characteristic of CRYOGLOBULINEMIA.

Cryoproteins [M0005378]

Cryptophycins [M0491341]
Peptolides forming 16-membered macrolides, composed of two ester linkages, two amide linkages and seven asymmetric centers. They have been found in CYANOBACTERIA and are TUBULIN MODULATORS.

Crystallins [M0005393]
A heterogeneous family of water-soluble structural proteins found in cells of the vertebrate lens. The presence of these proteins accounts for the transparency of the lens. The family is composed of four major groups, alpha, beta, gamma, and delta, and several minor groups, which are classed on the basis of size, charge, immunological properties, and vertebrate source. Alpha, beta, and delta crystallins occur in avian and reptilian lenses, while alpha, beta, and gamma crystallins occur in all other lenses.

CsA-Neoral [M0025281]

Cu-Superoxide Dismutase [M0020827]

Cu-Zn Superoxide Dismutase [M0020828]

Cullin Proteins [M0446344]
A family of structurally related proteins that were originally discovered for their role in cell-cycle regulation in CAENORHABDITIS ELEGANS. They play important roles in regulation of the CELL CYCLE and as components of UBIQUITIN-PROTEIN LIGASES.

Cuprenil [M0016124]

Cuprimine [M0016123]

CY-116 [M0351467]

Cyclic ADP-ribose Hydrolase [M0410130]
EC 3.2.2.5

Cyclic AMP Receptor Protein [M0003612]
A transcriptional regulator in prokaryotes which, when activated by binding cyclic AMP, acts at several promoters. Cyclic AMP receptor protein was originally identified as a catabolite gene activator protein. It was subsequently shown to regulate several functions unrelated to catabolism, and to be both a negative and a positive regulator of transcription. Cell surface cyclic AMP receptors are not included (CYCLIC AMP RECEPTORS), nor are the eukaryotic cytoplasmic cyclic AMP receptor proteins, which are the regulatory subunits of CYCLIC AMP-DEPENDENT PROTEIN KINASES.

Cyclic AMP Response Element Modulator [M0185189]
Cyclic AMP response element modulator is a basic leucine zipper transcription factor that is regulated by CYCLIC AMP. It plays an important role in SPERMATID development in the mammalian TESTIS.

Cyclic AMP Response Element-Binding Protein [M0026362]
A protein that has been shown to function as a calcium-regulated transcription factor as well as a substrate for depolarization-activated CALCIUM-CALMODULIN DEPENDENT PROTEIN KINASES. This protein functions to integrate both calcium and cAMP signals.

Cyclic AMP Response Element-Binding Protein A [M0481524]
A basic leucine zipper transcription factor that is highly homologous to ACTIVATING TRANSCRIPTION FACTOR 2. It binds the consensus site TGACGTCA of the cyclic AMP response element in partnership with either PROTO-ONCOGENE PROTEINS C-JUN or activating transcription factor 2.

Cyclic AMP-Dependent Protein Kinases [M0026998]
A group of enzymes that are dependent on cyclic AMP and catalyze the phosphorylation of serine or threonine residues on proteins.

Cyclic AMP-Phosphodiesterase Activator [M0003214]

Cyclic GMP-Dependent Protein Kinases [M0027000]
A group of enzymes that are dependent on cyclic GMP and catalyzes the phosphorylation of serine or threonine residues of proteins.

Cyclic Nucleotide-Regulated Protein Kinases [M0026996]
A group of enzymes that catalyzes the phosphorylation of serine or threonine residues of proteins and is dependent on cyclic nucleotides.

Cyclin A [M0029600]
A 33-kDa protein identical to adenovirus E1A-associated protein p60. Cyclin A regulates p33cdk2 and p34cdc2, and is necessary for progression through the S phase of the cell cycle.

Cyclin B [M0029601]
A 58-kDa protein that is regulated post-transcriptionally and post-translationally in the cell cycle.

Cyclin D1 [M0029612]
Protein encoded by the bcl-1 gene which plays a critical role in regulating the cell cycle. Overexpression of cyclin D1 is the result of bcl-1 rearrangement, a t(11;14) translocation, and is implicated in various neoplasms.

Cyclin E [M0029602]
A 50-kDa protein that complexes with cdk2 in the late G1 phase of the cell cycle.

Cyclin-Dependent Kinase 2 [M0191671]
A key regulator of CELL CYCLE progression. It partners with CYCLIN E to regulate entry into S PHASE and also interacts with CYCLIN A to phosphorylate RETINOBLASTOMA PROTEIN. Its activity is inhibited by CYCLIN-DEPENDENT KINASE INHIBITOR P27 and CYCLIN-DEPENDENT KINASE INHIBITOR P21.

Cyclin-Dependent Kinase 4 [M0208277]
Cyclin-dependent kinase 4 is a key regulator of G1 PHASE of the CELL CYCLE. It partners with CYCLIN D to phosphorylate RETINOBLASTOMA PROTEIN. CDK4 activity is inhibited by CYCLIN-DEPENDENT KINASE INHIBITOR P16.

Cyclin-Dependent Kinase 5 [M0224879]
A serine-threonine kinase that plays important roles in CELL DIFFERENTIATION; CELL MIGRATION; and CELL DEATH of NERVE CELLS. It is closely related to other CYCLIN-DEPENDENT KINASES but does not seem to participate in CELL CYCLE regulation.

Cyclin-Dependent Kinase 6 [M0228003]
Cyclin-dependent kinase 6 associates with CYCLIN D and phosphorylates RETINOBLASTOMA PROTEIN during G1 PHASE of the CELL CYCLE. It helps regulate the transition to S PHASE and its kinase activity is inhibited by CYCLIN-DEPENDENT KINASE INHIBITOR P18.

Cyclin-Dependent Kinase 9 [M0230514]
A multifunctional CDC2 kinase-related kinase that plays roles in transcriptional elongation, CELL DIFFERENTIATION and APOPTOSIS. It is a component of POSITIVE TRANSCRIPTIONAL ELONGATION FACTOR B.

Cyclin-Dependent Kinase Inhibitor p15 [M0236014]
An INK4 cyclin-dependent kinase inhibitor containing four ANKYRIN-LIKE REPEATS. INK4B is often inactivated by deletions, mutations, or hypermethylation in HEMATOLOGIC NEOPLASMS.

Cyclin-Dependent Kinase Inhibitor p16 [M0029615]
A product of the p16 tumor suppressor gene (GENES, P16). It is also called INK4 or INK4A because it is the prototype member of the INK4 CYCLIN-DEPENDENT KINASE INHIBITORS. This protein is produced from the alpha mRNA transcript of the p16 gene. The other gene product, produced from the alternatively spliced beta transcript, is TUMOR SUPPRESSOR PROTEIN P14ARF. Both p16 gene products have tumor suppressor functions.

Cyclin-Dependent Kinase Inhibitor p18 [M0240536]
An INK4 cyclin-dependent kinase inhibitor containing five ANKYRIN-LIKE REPEATS. Aberrant expression of this protein has been associated with deregulated EPITHELIAL CELL growth, organ enlargement, and a variety of NEOPLASMS.

Cyclin-Dependent Kinase Inhibitor p19 [M0477673]
An INK4 cyclin-dependent kinase inhibitor containing five ANKYRIN REPEATS. Aberrant expression of this protein has been associated with TESTICULAR CANCER.

Cyclin-Dependent Kinase Inhibitor p21 [M0224308]
A cyclin-dependent kinase inhibitor that mediates TUMOR SUPRESSOR PROTEIN P53-dependent CELL CYCLE arrest. p21 interacts with a range of CYCLIN-DEPENDENT KINASES and associates with PROLIFERATING CELL NUCLEAR ANTIGEN and CASPASE 3.

Cyclin-Dependent Kinase Inhibitor p27 [M0203045]
A cyclin-dependent kinase inhibitor that coordinates the activation of CYCLIN and CYCLIN-DEPENDENT KINASES during the CELL CYCLE. It interacts with active CYCLIN D complexed to CYCLIN-DEPENDENT KINASE 4 in proliferating cells, while in arrested cells it binds and inhibits CYCLIN E complexed to CYCLIN-DEPENDENT KINASE 2.

Cyclin-Dependent Kinase Inhibitor p57 [M0245969]
A potent inhibitor of CYCLIN-DEPENDENT KINASES in G1 PHASE and S PHASE. In humans, aberrant expression of p57 is associated with various NEOPLASMS as well as with BECKWITH-WIEDEMANN SYNDROME.

Cyclin-Dependent Kinase Inhibitor Proteins [M0477620]
A group of cell cycle proteins that negatively regulate the activity of CYCLIN/CYCLIN-DEPENDENT KINASE complexes. They inhibit CELL CYCLE progression and help control CELL PROLIFERATION following GENOTOXIC STRESS as well as during CELL DIFFERENTIATION.

Cyclin-Dependent Kinases [M0028197]
Protein kinases that control cell cycle progression in all eukaryotes and require physical association with CYCLINS to achieve full enzymatic activity. Cyclin-dependent kinases are regulated by phosphorylation and dephosphorylation events.

Cyclins [M0024762]
Regulatory proteins that function in the cell cycle to activate maturation promoting factor. They complex with p34cdc2 (PROTEIN P34CDC2), the catalytic subunit of MATURATION-PROMOTING FACTOR, and modulate its protein kinase activity. Cyclins themselves have no enzymatic activity.

Cycloleucine [M0005476]
An amino acid formed by cyclization of leucine. It has cytostatic, immunosuppressive and antineoplastic activities.

Cyclooxygenase 1 [M0260351]
A constitutively-expressed subtype of prostaglandin-endoperoxide synthase. It plays an important role in many cellular processes.

Cyclooxygenase 2 [M0258705]
An inducibly-expressed subtype of prostaglandin-endoperoxide synthase. It plays an important role in many cellular processes and INFLAMMATION. It is the target of COX2 INHIBITORS.

Cyclooxygenase 2 Inhibitors [M0446346]
A subclass of cyclooxygenase inhibitors with specificity for CYCLOOXYGENASE-2.

Cyclophilin A [M0029249]
A 17-KDa cytoplasmic PEPTIDYLPROLYL ISOMERASE involved in immunoregulation. It is a member of the cyclophilin family of proteins that binds to CYCLOSPORINE.

Cyclophilins [M0356321]
A family of peptidyl-prolyl cis-trans isomerases that bind to CYCLOSPORINS and regulate the IMMUNE SYSTEM. EC 5.2.1.-

Cycloserine [M0005492]
Antibiotic substance produced by Streptomyces garyphalus.

Cyclosporine [M0025279]
A cyclic undecapeptide from an extract of soil fungi. It is a powerful immunosupressant with a specific action on T-lymphocytes. It is used for the prophylaxis of graft rejection in organ and tissue transplantation. (From Martindale, The Extra Pharmacopoeia, 30th ed).

Cyclosporins [M0005493]
A group of closely related cyclic undecapeptides from the fungi Trichoderma polysporum and Cylindocarpon lucidum. They have some antineoplastic and antifungal action and significant immunosuppressive effects. Cyclosporins have been proposed as adjuvants in tissue and organ transplantation to suppress graft rejection.

Cyclotides [M0456600]
A continuous circle of peptide bonds, typically of 2-3 dozen AMINO ACIDS, so there is no free N- or C-terminus. They are further characterized by six conserved CYSTEINE residues that form CYSTINE KNOT MOTIFS.

Cystamucil [M0445991]

Cystathionine [M0005532]

Cystathionine beta-Synthase [M0005533]
A multifunctional pyridoxal phosphate enzyme. In the second stage of cysteine biosynthesis it catalyzes the reaction of homocysteine with serine to form cystathionine with the elimination of water. Deficiency of this enzyme leads to HYPERHOMOCYSTEINEMIA and HOMOCYSTINURIA. EC 4.2.1.22.

Cystathionine gamma-Lyase [M0005534]
A multifunctional pyridoxal phosphate enzyme. In the final step in the biosynthesis of cysteine it catalyzes the cleavage of cystathionine to yield cysteine, ammonia, and 2-ketobutyrate. EC 4.4.1.1.

Cystatin A [M0024321]

Cystatins [M0024322]
A homologous group of endogenous cysteine proteinase inhibitors. Four distinct families are recognized within the cystatin superfamily: cystatin B or stefins; cystatin C or post-gamma-globulin; egg-white or chicken cystatin; and kininogen cystatin. The cystatins inhibit most Cysteine Endopeptidases of the papain type, and other peptidases which have a sulfhydryl group at the active site.

Cysteic Acid [M0005538]
Beta-Sulfoalanine. An amino acid with a C-terminal sulfonic acid group which has been isolated from human hair oxidized with permanganate. It occurs normally in the outer part of the sheep's fleece, where the wool is exposed to light and weather.

Cysteine [M0005539]
A thiol-containing non-essential amino acid that is oxidized to form CYSTINE.

Cysteine Dioxygenase [M0073063]
An enzyme that catalyzes the conversion of L-CYSTEINE to 3-sulfinoalanine (3-sulfino-L-alanine) in the CYSTEINE metabolism and TAURINE and hypotaurine metabolic pathways.

Cysteine Endopeptidases [M0005542]
ENDOPEPTIDASES which have a cysteine involved in the catalytic process. This group of enzymes is inactivated by sulfhydryl reagents. EC 3.4.22.

Cysteine Hydrochloride [M0333361]

Cysteine Synthase [M0005547]
An enzyme that catalyzes the biosynthesis of cysteine in microorganisms and plants from O-acetyl-L-serine and hydrogen sulfide. This enzyme was formerly listed as EC 4.2.99.8.

Cysteine Synthase A [M0005548]

Cysteinyldopa [M0005549]
Found in large amounts in the plasma and urine of patients with malignant melanoma. It is therefore used in the diagnosis of melanoma and for the detection of postoperative metastases. Cysteinyldopa is believed to be formed by the rapid enzymatic hydrolysis of 5-S-glutathionedopa found in melanin-producing cells.

Cystic Fibrosis Transmembrane Conductance Regulator [M0028383]
A chloride channel that regulates secretion in many exocrine tissues. Abnormalities in the CFTR gene have been shown to cause cystic fibrosis. (Hum Genet 1994;93(4):364-8)

Cystine [M0005555]
A covalently linked dimeric nonessential amino acid formed by the oxidation of CYSTEINE. Two molecules of cysteine are joined together by a disulfide bridge to form cystine.

Cystinyl Aminopeptidase [M0015705]
A zinc-containing sialoglycoprotein that is used to study aminopeptidase activity in the pathogenesis of hypertension. EC 3.4.11.3.

Cystorelin [M0012448]

Cytidine Deaminase [M0005569]
An enzyme that catalyzes the deamination of cytidine, forming uridine. EC 3.5.4.5.

Cytochrome a Group [M0447608]
Cytochromes (electron-transporting proteins) in which the heme prosthetic group is heme a, i.e., the iron chelate of cytoporphyrin IX. (From Enzyme Nomenclature, 1992, p539)

Cytochrome aa3 [M0447606]
A dimer of CYTOCHROME A and CYTOCHROME A3.

Cytochrome b Group [M0005582]
Cytochromes (electron-transporting proteins) with protoheme (HEME B) as the prosthetic group.

Cytochrome b6f Complex [M0124802]
A protein complex that includes CYTOCHROME B6 and CYTOCHROME F. It is found in the THYLAKOID MEMBRANE and plays an important role in process of PHOTOSYNTHESIS by transferring electrons from PLASTOQUINONE to PLASTOCYANIN or CYTOCHROME C6. The transfer of electrons is coupled to the transport of PROTONS across the membrane.

Cytochrome bc1 [M0447642]
A dimer of CYTOCHROME B and CYTOCHROME C1.

Cytochrome bf [M0447816]

Cytochrome c Group [M0005583]
A group of cytochromes with covalent thioether linkages between either or both of the vinyl side chains of protoheme and the protein. (Enzyme Nomenclature, 1992, p539)

Cytochrome c Oxidase Subunit VIa [M0365809]

Cytochrome c-551 Peroxidase [M0005596]

Cytochrome d Group [M0027098]
Cytochromes (electron-transporting proteins) with a tetrapyrrolic chelate of iron as a prosthetic group in which the degree of conjugation of double bonds is less than in porphyrin. (From Enzyme Nomenclature, 1992, p539)

Cytochrome P-450 CYP1A1 [M0028818]
A liver microsomal cytochrome P-450 monooxygenase capable of biotransforming xenobiotics such as polycyclic hydrocarbons and halogenated aromatic hydrocarbons into carcinogenic or mutagenic compounds. They have been found in mammals and fish. This enzyme, encoded by CYP1A1 gene, can be measured by using ethoxyresorufin as a substrate for the ethoxyresorufin O-deethylase activity.

Cytochrome P-450 CYP1A2 [M0028854]
A cytochrome P-450 monooxygenase that can be induced by polycyclic aromatic xenobiotics in the liver of human and several animal species. This enzyme is of significant clinical interest due to the large number of drug interactions associated with its induction and its metabolism of THEOPHYLLINE. Caffeine is considered to be a model substrate for this enzyme. CYP1A2 activity can also be increased by environmental factors such as cigarette smoking, charbroiled meat, cruciferous vegetables, and a number of drugs including phenytoin, phenobarbital, and omeprazole.

Cytochrome P-450 CYP27A1 [M0072863]
An NAPH-dependent cytochrome P450 enzyme that catalyzes the oxidation of the side chain of sterol intermediates such as the 27-hydroxylation of 5-beta-cholestane-3-alpha,7-alpha, 12-alpha-triol. Cytochrome P-450 CYP27A1 is a mitochondrial enzyme; however microsomal-derived homologs of the enzyme have been identified and are included under this heading.

Cytochrome P-450 CYP2B1 [M0028816]
A major cytochrome P-450 enzyme which is inducible by PHENOBARBITAL in both the LIVER and SMALL INTESTINE. It is active in the metabolism of compounds like pentoxyresorufin, TESTOSTERONE, and ANDROSTENEDIONE. This enzyme, encoded by CYP2B1 gene, also mediates the activation of CYCLOPHOSPHAMIDE and IFOSFAMIDE to MUTAGENS.

Cytochrome P-450 CYP2D6 [M0028855]
A cytochrome P450 enzyme that catalyzes the hydroxylation of many drugs and environmental chemicals, such as DEBRISOQUINE; ADRENERGIC RECEPTOR ANTAGONISTS; and TRICYCLIC ANTIDEPRESSANTS. This enzyme is deficient in up to 10 percent of the Caucasian population.

Cytochrome P-450 CYP2E1 [M0028857]
An ethanol-inducible cytochrome P450 enzyme that metabolizes several precarcinogens, drugs, and solvents to reactive metabolites. Substrates include alcohol; NITROSAMINES; BENZENE; URETHANE; and other low molecular weight compounds. CYP2E1 has been used as an enzyme marker in the study of alcohol abuse.

Cytochrome P-450 CYP2R1 [M0493773]
A microsomal vitamin D 25-hydroxylase that is closely related to cytochrome P-450 CYP27A1.

Cytochrome P-450 CYP3A [M0082919]
A cytochrome P-450 monooxygenase that is involved in an NADPH-dependent electron transport pathway by oxidizing a variety of structurally unrelated compounds, including STEROIDS; FATTY ACIDS; and XENOBIOTICS. This enzyme has clinical significance due to its ability to metabolize a diverse array of clinically important drugs such as CYCLOSPORINE; VERAPAMIL; and MIDAZOLAM. This enzyme also catalyzes the N-demethylation of ERYTHROMYCIN.

Cytochrome P-450 Enzyme System [M0005591]
A superfamily of hundreds of closely related HEMEPROTEINS found throughout the phylogenetic spectrum, from animals, plants, fungi, to bacteria. They include numerous complex monooxygenases (MIXED FUNCTION OXYGENASES). In animals, these P-450 enzymes serve two major functions: (1) biosynthesis of steroids, fatty acids, and bile acids; (2) metabolism of endogenous and a wide variety of exogenous substrates, such as toxins and drugs (BIOTRANSFORMATION). They are classified, according to their sequence similarities rather than functions, into CYP gene families (>40% homology) and subfamilies (>59% homology). For example, enzymes from the CYP1, CYP2, and CYP3 gene families are responsible for most drug metabolism.

Cytochrome P-450 Monooxygenase [M0005593]

Cytochrome P-450 Oxygenase [M0005592]

Cytochrome Peroxidase [M0005595]

Cytochrome Reductases [M0005597]

Cytochrome-B(5) Reductase [M0073097]
A FLAVOPROTEIN oxidoreductase that occurs both as a soluble enzyme and a membrane-bound enzyme due to ALTERNATIVE SPLICING of a single mRNA. The soluble form is present mainly in ERYTHROCYTES and is involved in the reduction of METHEMOGLOBIN. The membrane-bound form of the enzyme is found primarily in the ENDOPLASMIC RETICULUM and outer mitochondrial membrane, where it participates in the desaturation of FATTY ACIDS; CHOLESTEROL biosynthesis and drug metabolism. A deficiency in the enzyme can result in METHEMOGLOBINEMIA.

Cytochrome-c Oxidase Subunit III [M0005590]

Cytochrome-c Oxidase Subunit IV [M0333367]

Cytochrome-c Peroxidase [M0005594]
A hemeprotein which catalyzes the oxidation of ferrocytochrome c to ferricytochrome c in the presence of hydrogen peroxide. EC 1.11.1.5.

Cytochromes [M0005598]
Hemeproteins whose characteristic mode of action involves transfer of reducing equivalents which are associated with a reversible change in oxidation state of the prosthetic group. Formally, this redox change involves a single-electron, reversible equilibrium between the Fe(II) and Fe(III) states of the central iron atom (From Enzyme Nomenclature, 1992, p539). The various cytochrome subclasses are organized by the type of HEME and by the wavelength range of their reduced alpha-absorption bands.

Cytochromes a [M0027097]
A subclass of heme a containing cytochromes that have two imidazole nitrogens as axial ligands and an alpha-band absorption of 605 nm. They are found in a variety of microorganisms and in eucaryotes as a low-spin cytochrome component of MITOCHONDRIAL ELECTRON TRANSPORT COMPLEX IV.

Cytochromes a1 [M0077986]
A subclass of heme a containing cytochromes have a reduced alpha-band absorption of 587-592 nm. They are primarily found in microorganisms.

Cytochromes a3 [M0447607]
A subclass of heme a containing cytochromes with an alpha-band absorption of 605 nm. They are found in a variety of microorganisms and in eukaryotes as a high-spin cytochrome component of MITOCHONDRIAL ELECTRON TRANSPORT COMPLEX IV.

Cytochromes b [M0447724]
Cytochromes of the b group that have alpha-band absorption of 563-564 nm. They occur as subunits in MITOCHONDRIAL ELECTRON TRANSPORT COMPLEX III.

Cytochromes b5 [M0024183]
Cytochromes of the b group that are found bound to cytoplasmic side of ENDOPLASMIC RETICULUM. They serve as electron carrier proteins for a variety of membrane-bound OXYGENASES. They are reduced by the enzyme CYTOCHROME-B(5) REDUCTASE.

Cytochromes b6 [M0447812]
Cytochromes of the b group that are found as components of the CYTOCHROME B6F COMPLEX. They contain two non-covalently bound HEME B groups.

Cytochromes c [M0447732]
Cytochromes of the c type that are found in eukaryotic MITOCHONDRIA. They serve as redox intermediates that accept electrons from MITOCHONDRIAL ELECTRON TRANSPORT COMPLEX III and transfer them to MITOCHONDRIAL ELECTRON TRANSPORT COMPLEX IV.

Cytochromes c' [M0005584]
A widely occurring subclass of c type cytochromes which function as electron carriers in the electron transport chain in photosynthetic and denitrifying BACTERIA.

Cytochromes c1 [M0005586]
The 30-kDa membrane-bound c-type cytochrome protein of mitochondria that functions as an electron donor to CYTOCHROME C GROUP in the mitochondrial and bacterial RESPIRATORY CHAIN. (From Enzyme Nomenclature, 1992, p545)

Cytochromes c2 [M0071689]
Type C cytochromes that are small (12-14 kD) single-heme proteins. They function as mobile electron carriers between membrane-bound enzymes in photosynthetic BACTERIA.

Cytochromes c6 [M0068930]
Cytochromes of the c type that are involved in the transfer of electrons from CYTOCHROME B6F COMPLEX and PHOTOSYSTEM I.

Cytochromes f [M0068936]
Cytochromes f are found as components of the CYTOCHROME B6F COMPLEX. They play important role in the transfer of electrons from PHOTOSYSTEM I to PHOTOSYSTEM II.

Cytokine Receptor Common beta Subunit [M0495194]
A receptor subunit that is a shared component of the INTERLEUKIN-3 RECEPTOR; the INTERLEUKIN-5 RECEPTOR; and the GM-CSF RECEPTOR. High affinity receptor complexes are formed with each of these receptors when their respective alpha subunits are combined with this shared beta subunit.

Cytokine Receptor gp130 [M0182947]
A cytokine receptor that acts through the formation of oligomeric complexes of itself with a variety of CYTOKINE RECEPTORS.

Cytokines [M0024747]
Non-antibody proteins secreted by inflammatory leukocytes and some non-leukocytic cells, that act as intercellular mediators. They differ from classical hormones in that they are produced by a number of tissue or cell types rather than by specialized glands. They generally act locally in a paracrine or autocrine rather than endocrine manner.

Cytomel [M0021976]

Cytosine Deaminase [M0073103]
An enzyme which catalyzes the deamination of CYTOSINE resulting in the formation of URACIL. It can also act on 5-methylcytosine to form THYMIDINE.

Cytoskeletal Proteins [M0005620]
Major constituent of the cytoskeleton found in the cytoplasm of eukaryotic cells. They form a flexible framework for the cell, provide attachment points for organelles and formed bodies, and make communication between parts of the cell possible.

D-Ala(2),MePhe(4),Met(0)-ol-enkephalin [M0373533]
A stable synthetic analog of methionine enkephalin (ENKEPHALIN, METHIONINE). Actions are similar to those of methionine enkephalin. Its effects can be reversed by narcotic antagonists such as naloxone.

D-Alanine Transaminase [M0072253]
A PYRIDOXAL PHOSPHATE containing enzyme that catalyzes the reversible transfer of an amino group between D-Alanine and ALPHA-KETOGLUTARATE to form PYRUVATE and D-GLUTAMATE, respectively. It plays a role in the synthesis of the bacterial CELL WALL. This enzyme was formerly classified as EC 2.6.1.10.

D-Amino-Acid Oxidase [M0005635]

D-Aspartate [M0378610]

D-Aspartate Oxidase [M0072564]
An FAD-dependent peroxisomal flavoenzyme, this catalyzes the oxidative deamination of D-ASPARTATE to OXALOACETATE and AMMONIA using oxygen as electron acceptor.

D-Aspartic Acid [M0378511]
The D-isomer of ASPARTIC ACID.

D-Glucuronolactone Dehydrogenase [M0000676]

D-Glutamate [M0028011]

D-Glutamine [M0009382]

D-Pen2, L-Pen5-Enkephalin [M0333394]

D-Xylulose Reductase [M0080441]
An enzyme that plays a role in the PENTOSES and GLUCURONATES interconversion pathway by catalyzing the oxidation of XYLITOL to D-xylulose. This enzyme has been found to be specific for NAD+.

D1 Photosystem II Protein, Plant [M0170014]

Dactinomycin [M0005644]
A compound composed of a two CYCLIC PEPTIDES attached to a phenoxazine that is derived from STREPTOMYCES parvullus. It binds to DNA and inhibits RNA synthesis (transcription), with chain elongation more sensitive than initiation, termination, or release. As a result of impaired mRNA production, protein synthesis also declines after dactinomycin therapy. (From AMA Drug Evaluations Annual, 1993, p2015)

Dairyaid [M0477142]

Dampo Mucopect [M0447116]

Daptomycin [M0026638]
A lipopeptide antibiotic that inhibits gram-positive bacteria.

Daptomycin, 9-L beta-Aspartic Acid [M0329226]

Dayto Anase [M0002934]

DCMP Deaminase [M0006001]
An enzyme that catalyzes the hydrolytic deamination of deoxycytidylic acid to deoxyuridylic acid and ammonia. It plays an important role in the regulation of the pool of deoxynucleotides in higher organisms. The enzyme also acts on some 5-substituted deoxycytidylic acids. EC 3.5.4.12.

DDAVP [M0369333]

DEAD Box Helicase p68 [M0159382]

DEAD-box RNA Helicases [M0493668]
A large family of RNA helicases that share a common protein motif with the single letter amino acid sequence D-E-A-D (Asp-Glu-Ala-Asp). In addition to RNA helicase activity, members of the DEAD-box family participate in other aspects of RNA metabolism and regulation of RNA function.

Deamino Arginine Vasopressin [M0474041]
A synthetic analog of the pituitary hormone, ARGININE VASOPRESSIN. Its action is mediated by the VASOPRESSIN receptor V2. It has prolonged antidiuretic activity, but little pressor effects. It also modulates levels of circulating FACTOR VIII and VON WILLEBRAND FACTOR.

Death Domain Receptor Signaling Adaptor Proteins [M0492979]
Intracellular signaling adaptor proteins that bind to the cytoplasmic death domain region found on DEATH DOMAIN RECEPTORS. Many of the proteins in this class take part in intracellular signaling from TUMOR NECROSIS FACTOR RECEPTORS.

Decanoyl CoA Dehydrogenase [M0008261]

Decapeptyl [M0026319]

Decoy FAS Receptors [M0492601]

Decoy TRAIL Receptors [M0492600]

Defensins [M0135759]
Family of antimicrobial peptides that have been identified in humans, animals, and plants. They are thought to play a role in host defenses against infections, inflammation, wound repair, and acquired immunity.

Defibrase [M0333034]

DEFICIENS Protein [M0267624]
DEFICIENS is a homeotic gene involved in the genetic control of Antirrhinum majus flower development. Its protein is one of the four founder proteins that structurally define the superfamily of MADS DOMAIN PROTEINS.

Deficiens-Agamous-Like Proteins [M0238872]

Dehydroascorbatase [M0005758]
Catalyzes the hydrolysis of the gamma lactone, dehydroascorbate, to diketogulonate.

Delayed Rectifier Potassium Channels [M0236741]
A group of slow opening and closing voltage-gated potassium channels. Because of their delayed activation kinetics they play an important role in controlling ACTION POTENTIAL duration.

Delta Sleep-Inducing Peptide [M0005794]
A nonapeptide that is found in neurons, peripheral organs, and plasma. This neuropeptide induces mainly delta sleep in mammals. In addition to sleep, the peptide has been observed to affect electrophysiological activity, neurotransmitter levels in the brain, circadian and locomotor patterns, hormonal levels, psychological performance, and the activity of neuropharmacological drugs including their withdrawal.

delta, beta-Globin [M0009282]

delta-Crystallins [M0005394]
A subclass of crystallins found in the lens (LENS, CRYSTALLINE) in BIRDS and REPTILES. They are inactive forms of the enzyme argininosuccinate lyase.

delta-Globin [M0009285]

delta-Sarcoglycan [M0266521]

delta-Tryptases [M0496634]

Deltaretrovirus Antibodies [M0023838]
Antibodies reactive with various types of human T-cell leukemia/lymphoma antigens or bovine leukemia virus antigens.

Deltaretrovirus Antigens [M0023845]
Antigens associated with the DELTARETROVIRUS; HTLV-I ANTIGENS and HTLV-II ANTIGENS belong to this group.

Demser [M0029395]

Dental Enamel Proteins [M0005877]
The proteins that are part of the dental enamel matrix.

Deoxycytidine Kinase [M0005998]
An enzyme that catalyzes reversibly the phosphorylation of deoxycytidine with the formation of a nucleoside diphosphate and deoxycytidine monophosphate. Cytosine arabinoside can also act as an acceptor. All natural nucleoside triphosphates, except deoxycytidine triphosphate, can act as donors. The enzyme is induced by some viruses, particularly the herpes simplex virus (HERPESVIRUS HOMINIS). EC 2.7.1.74.

Deoxyhemoglobin S [M0010125]

Deoxyribodipyrimidine Photo-Lyase [M0006660]
An enzyme that catalyzes the reactivation by light of UV-irradiated DNA. It breaks two carbon-carbon bonds in pyrimidine dimers in DNA. EC 4.1.99.3.

Deoxyribonuclease (Pyrimidine Dimer) [M0073441]
An enzyme which catalyzes an endonucleolytic cleavage near PYRIMIDINE DIMERS to produce a 5'-phosphate product. The enzyme acts on the damaged DNA strand, from the 5' side of the damaged site.

Deoxyribonuclease BamHI [M0023435]
One of the Type II site-specific deoxyribonucleases (EC 3.1.21.4). It recognizes and cleaves the sequence G/GATCC at the slash. BamHI is from Bacillus amyloliquefaciens N. Numerous isoschizomers have been identified. EC 3.1.21.-.

Deoxyribonuclease BstFI [M0023471]

Deoxyribonuclease EcoRI [M0023459]
One of the Type II site-specific deoxyribonucleases (EC 3.1.21.4). It recognizes and cleaves the sequence G/AATTC at the slash. EcoRI is from E coliRY13. Several isoschizomers have been identified. EC 3.1.21.-.

Deoxyribonuclease EcoVIII [M0023476]

Deoxyribonuclease HindIII [M0023466]
One of the Type II site-specific deoxyribonucleases (EC 3.1.21.4). It recognizes and cleaves the sequence A/AGCTT at the slash. HindIII is from Haemophilus influenzae R(d). Numerous isoschizomers have been identified. EC 3.1.21.-.

Deoxyribonuclease HpaII [M0028377]
One of the Type II site-specific deoxyribonucleases (EC 3.1.21.4). It recognizes and cleaves the sequences C/CGG and GGC/C at the slash. HpaII is from Haemophilus parainfluenzae. Several isoschizomers have been identified. EC 3.1.21.-.

Deoxyribonuclease I [M0006007]
An enzyme capable of hydrolyzing highly polymerized DNA by splitting phosphodiester linkages, preferentially adjacent to a pyrimidine nucleotide. This catalyzes endonucleolytic cleavage of DNA yielding 5'-phosphodi- and oligonucleotide end-products. The enzyme has a preference for double-stranded DNA.

Deoxyribonuclease IV (Phage T4-Induced) [M0151167]
An enzyme which catalyzes the endonucleolytic cleavage of phosphodiester bonds at purinic or apyrimidinic sites (AP-sites) to produce 5'-Phosphooligonucleotide end products. The enzyme prefers single-stranded DNA (ssDNA) and was formerly classified as EC 3.1.4.30.

Deoxyribonuclease MspI [M0028378]

Deoxyribonuclease SsoI [M0023464]

Deoxyribonucleases [M0006014]
Enzymes which catalyze the hydrolases of ester bonds within DNA. EC 3.1.-.

Deoxyribonucleases, Type I Site-Specific [M0023491]
Enzyme systems containing three different subunits and requiring ATP, S-adenosylmethionine, and magnesium for endonucleolytic activity to give random double-stranded fragments with terminal 5'-phosphates. They function also as DNA-dependent ATPases and modification methylases, catalyzing the reactions of EC 2.1.1.72 and EC 2.1.1.73 with similar site-specificity. The systems recognize specific short DNA sequences and cleave at sites remote from the recognition sequence. Enzymes from different microorganisms with the same specificity are called isoschizomers. EC 3.1.21.3.

Deoxyribonucleases, Type II Site-Specific [M0023490]
Enzyme systems containing a single subunit and requiring only magnesium for endonucleolytic activity. The corresponding modification methylases are separate enzymes. The systems recognize specific short DNA sequences and cleave either within, or at a short specific distance from, the recognition sequence to give specific double-stranded fragments with terminal 5'-phosphates. Enzymes from different microorganisms with the same specificity are called isoschizomers. EC 3.1.21.4.

Deoxyribonucleases, Type III Site-Specific [M0023503]
Enzyme systems composed of two subunits and requiring ATP and magnesium for endonucleolytic activity; they do not function as ATPases. They exist as complexes with modification methylases of similar specificity listed under EC 2.1.1.72 or EC 2.1.1.73. The systems recognize specific short DNA sequences and cleave a short distance, about 24 to 27 bases, away from the recognition sequence to give specific double-stranded fragments with terminal 5'-phosphates. Enzymes from different microorganisms with the same specificity are called isoschizomers. EC 3.1.21.5.

Deoxyribonucleoproteins [M0006015]
Proteins conjugated with deoxyribonucleic acids (DNA) or specific DNA.

Depsipeptides [M0458175]
Compounds consisting of chains of AMINO ACIDS alternating with CARBOXYLIC ACIDS via ester and amide linkages. They are commonly cyclized.

Depsipeptides, Cyclic [M0458176]

Dermatophagoides Allergens [M0419889]

Dermatophagoides farinae Allergens [M0419890]

Dermatophagoides pteronyssinus Allergens [M0419891]

Dermodress [M0369417]

Dermolysins [M0008009]

Dermotricine [M0373261]

Desert Hedgehog Protein [M0235923]

Desmin [M0006077]
An intermediate filament protein found predominantly in smooth, skeletal, and cardiac muscle cells. Localized at the Z line. MW 50,000 to 55,000 is species dependent.

Desmocollins [M0112627]
A group of desmosomal cadherins with cytoplasmic tails that are divergent from those of classical CADHERINS. Their intracytoplasmic domains bind PLAKOGLOBIN; PLAKOPHILINS; and DESMOPLAKINS.

Desmogalen [M0492528]

Desmoglein 1 [M0226746]
A desmosomal cadherin that is an autoantigen in the acquired skin disorder PEMPHIGUS FOLIACEUS.

Desmoglein 2 [M0408335]
A CALCIUM-dependent adhesion molecule of DESMOSOMES that also plays a role in embryonic STEM CELL proliferation.

Desmoglein 3 [M0112634]
A desmosomal cadherin that is an autoantigen in the acquired skin disorder PEMPHIGUS VULGARIS.

Desmogleins [M0112628]
A group of desmosomal cadherins with cytoplasmic tails that resemble those of classical CADHERINS.

Desmolases [M0012768]

Desmoplakin 1 [M0112631]

Desmoplakin 2 [M0112632]

Desmoplakins [M0112637]
Desmoplakins are cytoskeletal linker proteins that anchor INTERMEDIATE FILAMENTS to the PLASMA MEMBRANE at DESMOSOMES.

Desmopressin Acetate [M0330516]

Desmopressin Monoacetate [M0330515]

Desmosine [M0006081]
4-(4-Amino-4-carboxybutyl)-1-(5-amino-5-carboxypentyl)-3,5-bis(3-amino-3-carboxypropyl)pyridinium. A rare amino acid found in elastin, formed by condensation of four molecules of lysine into a pyridinium ring.

Desmosomal Cadherins [M0479560]
A single-pass transmembrane glycoproteins that mediate CALCIUM-dependent CELL ADHESION and are core components of DESMOSOMES.

Destrin [M0374745]
A member of the actin depolymerizing factors. Its depolymerizing activity is independent of HYDROGEN-ION CONCENTRATION.

Desulfofuscidin [M0478442]

Desulforubidin [M0478443]

Desulfoviridin [M0478444]

Dexnon [M0463498]

Dextranase [M0006105]

Dextrothyroxine [M0006144]
The dextrorotary isomer of the synthetic THYROXINE.

Dextrothyroxine Sodium [M0373453]

DGK alpha [M0029465]

DGK beta [M0029466]

DGK delta [M0029467]

DGK gamma [M0029468]

DGK-IV [M0029470]

Diacylglycerol Cholinephosphotransferase [M0004292]
An enzyme that catalyzes the synthesis of phosphatidylcholines from CDPcholine and 1,2-diacylglycerols. EC 2.7.8.2.

Diacylglycerol Kinase [M0029463]
An enzyme of the transferase class that uses ATP to catalyze the phosphorylation of diacylglycerol to a phosphatidate. EC 2.7.1.107.

Diacylglycerol O-Acyltransferase [M0073206]
An enzyme that catalyses the last step of the TRIACYLGLYCEROL synthesis reaction in which diacylglycerol is covalently joined to LONG-CHAIN ACYL COA to form triglyceride. It was formerly categorized as EC 2.3.1.124.

Diaminobenzidine Oxidase [M0010389]

Diaminopimelic Acid [M0006205]

Diapid [M0373045]

Diatracin [M0476496]

Diazepam Binding Inhibitor [M0121114]
An 86-amino acid polypeptide, found in central and peripheral tissues, that displaces diazepam from the benzodiazepine recognition site on the gamma-aminobutyric acid receptor (RECEPTORS, GABA). It also binds medium- and long-chain acyl-CoA esters and serves as an acyl-CoA transporter. This peptide regulates lipid metabolism.

Diazooxonorleucine [M0006241]
An amino acid that inhibits phosphate-activated glutaminase and interferes with glutamine metabolism. It is an antineoplastic antibiotic produced by an unidentified species of Streptomyces from Peruvian soil. (From Merck Index, 11th ed)

Dicarboxylic Acid Transporters [M0091877]
A family of organic anion transporters that specifically transport DICARBOXYLIC ACIDS such as alpha-ketoglutaric acid across cellular membranes.

Dicer Enzyme [M0378401]

Dietary Proteins [M0006342]
Proteins obtained from foods. They are the main source of the ESSENTIAL AMINO ACIDS.

Dietary Soybean Proteins [M0028725]
Proteins which are present in the edible portion of SOYBEANS.

Difluoromethylornithine [M0000790]

Diglyceride Acyltransferase 1 [M0443166]

Dihydrodipicolinate Reductase [M0073248]
An enzyme that catalyzes the oxidation of 2,3,4,5-tetrahydrodipicolinate to 2,3-dihydrodipicolinate using NAD(P)+ as a cofactor. It is found in BACTERIA and higher plants involved in the biosynthesis of DIAMINOPIMELIC ACID and LYSINE.

Dihydrolipoamide Dehydrogenase [M0012555]
A flavoprotein containing oxidoreductase that catalyzes the reduction of lipoamide by NADH to yield dihydrolipoamide and NAD+. The enzyme is a component of several MULTIENZYME COMPLEXES.

Dihydrolipoyllysine-Residue Acetyltransferase [M0073246]
An enzyme that catalyzes the acetyltransferase reaction using ACETYL CoA as an acetyl donor and dihydrolipoamide as acceptor to produce COENZYME A (CoA) and S-acetyldihydrolipoamide. It forms the (E2) subunit of the PYRUVATE DEHYDROGENASE COMPLEX.

Dihydroorotase [M0006391]
An enzyme that, in the course of pyrimidine biosynthesis, catalyzes ring closure by removal of water from N-carbamoylaspartate to yield dihydro-orotic acid. EC 3.5.2.3.

Dihydroorotate Oxidase [M0006392]
An enzyme that in the course of pyrimidine biosynthesis, catalyzes the oxidation of dihydro-orotic acid to orotic acid utilizing oxygen as the electron acceptor. This enzyme is a flavoprotein which contains both FLAVIN-ADENINE DINUCLEOTIDE and FLAVIN MONONUCLEOTIDE as well as iron-sulfur centers. EC 1.3.3.1.

Dihydropteridine Reductase [M0006412]
An enzyme that catalyzes the reduction of 6,7-dihydropteridine to 5,6,7,8-tetrahydropteridine in the presence of NADP+. Defects in the enzyme are a cause of PHENYLKETONURIA II. Formerly listed as EC 1.6.99.7.

Dihydropteroate Synthase [M0006413]
An enzyme that catalyzes the formation of dihydropteroate from p-aminobenzoic acid and dihydropteridine-hydroxymethyl-pyrophosphate. EC 2.5.1.15.

Dihydrouracil Dehydrogenase (NAD+) [M0073260]
An enzyme that catalyzes the oxidation of 5,6-dihydrouracil to URACIL using NAD as a cofactor. This enzyme also plays a role in the catabolism of the antimetabolite 5-FLUOROURACIL.

Dihydrouracil Dehydrogenase (NADP) [M0073263]
An oxidoreductase involved in pyrimidine base degradation. It catalyzes the catabolism of THYMINE; URACIL and the chemotherapeutic drug, 5-FLUOROURACIL.

Dihydroxyphenylalanine [M0006754]
A beta-hydroxylated derivative of phenylalanine. The D-form of dihydroxyphenylalanine has less physiologic activity than the L-form and is commonly used experimentally to determine whether the pharmacological effects of LEVODOPA are stereospecific.

Dihydroxyphenylalanine Hydrochloride, (2:1) [M0330404]

Diiodothyronines [M0006425]
These metabolites of THYROXINE are formed by the deiodination of T3 or reverse T3.

Diiodotyrosine [M0006426]
A product from the iodination of MONOIODOTYROSINE. In the biosynthesis of thyroid hormones, diiodotyrosine residues are coupled with other monoiodotyrosine or diiodotyrosine residues to form T4 or T3 thyroid hormones (THYROXINE and TRIIODOTHYRONINE).

Dilminal [M0332549]

Dilmintal [M0011910]

Dimethylallyltranstransferase [M0006457]
An enzyme that, in the pathway of cholesterol biosynthesis, catalyzes the condensation of isopentenyl pyrophosphate and dimethylallylpyrophosphate to yield pyrophosphate and geranylpyrophosphate. The enzyme then catalyzes the condensation of the latter compound with another molecule of isopentenyl pyrophosphate to yield pyrophosphate and farnesylpyrophosphate. EC 2.5.1.1.

Dimethylglycine Dehydrogenase [M0071748]
A FLAVOPROTEIN enzyme that catalyzes the oxidative demethylation of DIMETHYLGLYCINE to SARCOSINE and FORMALDEHYDE.

Dinitrogenase Reductase [M0025883]
A non-heme iron-sulfur protein isolated from Clostridium pasteurianum and other bacteria. It is a component of NITROGENASE along with molybdoferredoxin and is active in nitrogen fixation.

Dinucleosomes [M0015069]

Dioxygenases [M0464092]
Non-heme iron-containing enzymes that incorporate two atoms of OXYGEN into the substrate. They are important in biosynthesis of FLAVONOIDS; GIBBERELLINS; and HYOSCYAMINE; and for degradation of AROMATIC HYDROCARBONS.

Dipeptidases [M0006501]
EXOPEPTIDASES that specifically act on dipeptides. EC 3.4.13.

Dipeptides [M0006502]
Peptides composed of two amino acid units.

Dipeptidyl Peptidase I [M0262814]
A cysteine-type peptidase that is CHLORINE dependent and functions maximally at acidic pHs. At neutral pH, it polymerizes esters, aryl- and dipeptide amides. EC 3.4.14.1.

Dipeptidyl Peptidases [M0006503]
Enzymes which cleave dipeptides from the amino terminal of a polypeptide. Dipeptidyl peptidase I, II, III, IV are known. They hydrolyze the beta-naphthylamides of glycine-arginine, lysine-alanine, arginine-arginine and glycine-proline, respectively. DIPEPTIDYL PEPTIDASE I is cathepsin C. EC 3.4.14.-.

Diphosphotransferases [M0026977]
A class of phosphotransferases that catalyzes the transfer of diphosphate-containing groups. EC 2.7.6.

Dirigestran [M0012449]

Disaccharidases [M0006556]

DISC (Death Inducing Signaling Complex) [M0444186]

Discase [M0333215]

Disintegrins [M0028974]
A family of polypeptides purified from snake venoms, which contain the arginine-glycine-aspartic acid (RGD) sequence. The RGD tripeptide binds to integrin receptors and thus competitively inhibits normal integrin-ligand interactions. Disintegrins thus block adhesive functions and act as platelet aggregation inhibitors.

Distamycins [M0006593]
Oligopeptide antibiotics from Streptomyces distallicus. Their binding to DNA inhibits synthesis of nucleic acids.

Distreptase [M0020586]

DL-Arginine Acetate, Monohydrate [M0001684]

DNA (Cytosine-5-)-Methyltransferase [M0006648]
An enzyme that catalyzes the transfer of a methyl group from S-adenosylmethionine to the 5-position of cytosine or to the 6-position in adenine in mammalian DNA. EC 2.1.1.37.

DNA Glycosylases [M0073348]
A family of DNA repair enzymes that recognize damaged nucleotide bases and remove them by hydrolyzing the N-glycosidic bond that attaches them to the sugar backbone of the DNA molecule. The process called BASE EXCISION REPAIR can be completed by a DNA-(APURINIC OR APYRIMIDINIC SITE) LYASE which excises the remaining RIBOSE sugar from the DNA.

DNA Gyrase [M0379516]
A bacterial DNA topoisomerase II that catalyzes ATP-dependent breakage of both strands of DNA, passage of the unbroken strands through the breaks, and rejoining of the broken strands. Gyrase binds to DNA as a heterotetramer consisting two A and two B subunits. In the presence of ATP, gyrase is able to convert relaxed circular DNA duplex into a superhelix. In the absence of ATP, supercoiled DNA is relaxed by DNA gyrase.

DNA Gyrase A Subunit [M0197847]
One of the two subunits in DNA gyrase.

DNA Gyrase B Subunit [M0193335]
One of the two subunits in DNA gyrase.

DNA Helicase A [M0083525]

DNA Helicase E [M0083526]

DNA Helicase II [M0083527]

DNA Helicase III [M0077597]

DNA Helicases [M0006674]
Proteins that catalyze the unwinding of duplex DNA during replication by binding cooperatively to single-stranded regions of DNA or to short regions of duplex DNA that are undergoing transient opening. In addition DNA helicases are DNA-dependent ATPases that harness the free energy of ATP hydrolysis to translocate of DNA strands.

DNA Helix Destabilizing Proteins [M0006677]

DNA Ligases [M0017169]
Poly(deoxyribonucleotide):poly(deoxyribonucleotide)ligases. Enzymes that catalyze the joining of preformed deoxyribonucleotides in phosphodiester linkage during genetic processes during repair of a single-stranded break in duplex DNA. The class includes both EC 6.5.1.1 (ATP) and EC 6.5.1.2 (NAD).

DNA Modification Methylases [M0023492]
Enzymes that are part of the restriction-modification systems. They are responsible for producing a species-characteristic methylation pattern, on either adenine or cytosine residues, in a specific short base sequence in the host cell's own DNA. This methylated sequence will occur many times in the host-cell DNA and remain intact for the lifetime of the cell. Any DNA from another species which gains entry into a living cell and lacks the characteristic methylation pattern will be recognized by the restriction endonucleases of similar specificity and destroyed by cleavage. Most have been studied in bacterial systems, but a few have been found in eukaryotic organisms.

DNA Nucleotidylexotransferase [M0006657]
A non-template-directed DNA polymerase normally found in vertebrate thymus and bone marrow. It catalyzes the elongation of oligo- or polydeoxynucleotide chains and is widely used as a tool in the differential diagnosis of acute leukemias in man. EC 2.7.7.31.

DNA Nucleotidyltransferases [M0006659]
Enzymes that catalyze the incorporation of deoxyribonucleotides into a chain of DNA. EC 2.7.7.-.

DNA Polymerase beta [M0029624]
A DNA repair enzyme that catalyzes DNA synthesis during base excision DNA repair. EC 2.7.7.7.

DNA Polymerase I [M0006661]
A DNA-dependent DNA polymerase characterized in prokaryotes and may be present in higher organisms. It has both 3'-5' and 5'-3' exonuclease activity, but cannot use native double-stranded DNA as template-primer. It is not inhibited by sulfhydryl reagents and is active in both DNA synthesis and repair. EC 2.7.7.7.

DNA Polymerase II [M0006662]
A DNA-dependent DNA polymerase characterized in E. coli and other lower organisms. It may be present in higher organisms and has an intrinsic molecular activity only 5% of that of DNA Polymerase I. This polymerase has 3'-5' exonuclease activity, is effective only on duplex DNA with gaps or single-strand ends of less than 100 nucleotides as template, and is inhibited by sulfhydryl reagents. EC 2.7.7.7.

DNA Polymerase III [M0006663]
A DNA-dependent DNA polymerase characterized in E. coli and other lower organisms but may be present in higher organisms. Use also for a more complex form of DNA polymerase III designated as DNA polymerase III* or pol III* which is 15 times more active biologically than DNA polymerase I in the synthesis of DNA. This polymerase has both 3'-5' and 5'-3' exonuclease activities, is inhibited by sulfhydryl reagents, and has the same template-primer dependence as pol II. EC 2.7.7.7.

DNA Polymerase N3 [M0006664]

DNA Primase [M0029590]
A single-stranded DNA-dependent RNA polymerase that functions to initiate, or prime, DNA synthesis by synthesizing oligoribonucleotide primers. EC 2.7.7.-.

DNA Repair Enzymes [M0448961]
Enzymes that are involved in the reconstruction of a continuous two-stranded DNA molecule without mismatch from a molecule, which contained damaged regions.

DNA Repair Methyltransferase I [M0029472]

DNA Repair Methyltransferase II [M0029473]

DNA Restriction Enzymes [M0006671]
Enzymes that are part of the restriction-modification systems. They catalyze the endonucleolytic cleavage of DNA sequences which lack the species-specific methylation pattern in the host cell's DNA. Cleavage yields random or specific double-stranded fragments with terminal 5'-phosphates. The function of restriction enzymes is to destroy any foreign DNA that invades the host cell. Most have been studied in bacterial systems, but a few have been found in eukaryotic organisms. They are also used as tools for the systematic dissection and mapping of chromosomes, in the determination of base sequences of DNAs, and have made it possible to splice and recombine genes from one organism into the genome of another. EC 3.21.1.

DNA Restriction-Modification Enzymes [M0023522]
Systems consisting of two enzymes, a modification methylase and a restriction endonuclease. They are closely related in their specificity and protect the DNA of a given bacterial species. The methylase adds methyl groups to adenine or cytosine residues in the same target sequence that constitutes the restriction enzyme binding site. The methylation renders the target site resistant to restriction, thereby protecting DNA against cleavage.

DNA Topoisomerase IV [M0181519]
A bacterial DNA topoisomerase II that catalyzes ATP-dependent breakage of both strands of DNA, passage of the unbroken strands through the breaks, and rejoining of the broken strands. Topoisomerase IV binds to DNA as a heterotetramer consisting 2 parC and 2 parE subunits. Topoisomerase IV is a decatenating enzyme that resolves interlinked daughter chromosomes following DNA replication.

DNA Topoisomerases [M0379272]
Enzymes that regulate the topology of DNA by actions such as breaking, relaxing, passing, and rejoining strands of DNA in cells. These enzymes are important components of the DNA replication system. They are classified by their substrate specificities. DNA TOPOISOMERASE I enzymes act on a single strand of DNA. DNA TOPOISOMERASE II enzymes act on double strands of DNA.

DNA Topoisomerases, Type I [M0381011]
DNA TOPOISOMERASES that catalyze ATP-independent breakage of one of the two strands of DNA, passage of the unbroken strand through the break, and rejoining of the broken strand. DNA Topoisomerases, Type I enzymes reduce the topological stress in the DNA structure by relaxing the superhelical turns and knotted rings in the DNA helix.

DNA Topoisomerases, Type I, Archaeal [M0381014]
Archaeal enzymes of the DNA TOPOISOMERASES, TYPE I class that catalyze ATP-independent breakage of one of the two strands of DNA, passage of the unbroken strand through the break, and rejoining of the broken strand. These archaeal enzymes reduce the topological stress in the DNA structure by relaxing negatively, but not positively, supercoiled DNA.

DNA Topoisomerases, Type I, Bacterial [M0379444]
Bacterial enzymes of the DNA TOPOISOMERASES, TYPE I class that catalyze ATP-independent breakage of one of the two strands of DNA, passage of the unbroken strand through the break, and rejoining of the broken strand. These bacterial enzymes reduce the topological stress in the DNA structure by relaxing negatively, but not positively, supercoiled DNA.

DNA Topoisomerases, Type I, Eukaryotic [M0379445]
Eukaryotic enzymes of the DNA TOPOISOMERASES, TYPE I class that catalyze ATP-independent breakage of one of the two strands of DNA, passage of the unbroken strand through the break, and rejoining of the broken strand. These eukaryotic enzymes reduce the topological stress in the DNA structure by relaxing both negatively and positively supercoiled DNA.

DNA Topoisomerases, Type II [M0381050]
DNA TOPOISOMERASES that catalyze ATP-dependent breakage of both strands of DNA, passage of the unbroken strands through the breaks, and rejoining of the broken strands. These enzymes bring about relaxation of the supercoiled DNA and resolution of a knotted circular DNA duplex.

DNA Topoisomerases, Type II, Archaeal [M0381130]
Archaeal enzymes of the DNA TOPOISOMERASES, TYPE II class that catalyze ATP-dependent breakage of both strands of DNA, passage of the unbroken strands through the breaks, and rejoining of the broken strands. These enzymes bring about relaxation of the supercoiled DNA and resolution of a knotted circular DNA duplex.

DNA Topoisomerases, Type II, Bacterial [M0379493]
Bacterial enzymes of the DNA TOPOISOMERASES, TYPE II class that catalyze ATP-dependent breakage of both strands of DNA, passage of the unbroken strands through the breaks, and rejoining of the broken strands. These enzymes bring about relaxation of the supercoiled DNA duplex. Bacterial DNA topoisomerases in the Type II class exist as heterotetramers of 2 subunits, such as 2 gyrA and 2 gyrB in DNA GYRASE.

DNA Topoisomerases, Type II, Eukaryotic [M0383840]
Eukaryotic enzymes of the DNA TOPOISOMERASES, TYPE II class that catalyze ATP-dependent breakage of both strands of DNA, passage of the unbroken strands through the breaks, and rejoining of the broken strands. These enzymes bring about relaxation of the supercoiled DNA and resolution of a knotted circular DNA duplex. Isozymes of the eukaryotic DNA topoisomerase II consist of homodimers of alpha or beta subunits.

DNA-(Apurinic or Apyrimidinic Site) Lyase [M0073416]
A DNA repair enzyme that catalyses the excision of ribose residues at apurinic and apyrimidinic DNA sites that can result from the action of DNA GLYCOSYLASES. The enzyme catalyzes a beta-elimination reaction in which the C-O-P bond 3' to the apurinic or apyrimidinic site in DNA is broken, leaving a 3'-terminal unsaturated sugar and a product with a terminal 5'-phosphate. This enzyme was previously listed under EC 3.1.25.2.

DNA-Activated Protein Kinase [M0212384]
A serine-threonine protein kinase that, when activated by DNA, phosphorylates several DNA-binding protein substrates including the TUMOR SUPPRESSOR PROTEIN P53 and a variety of TRANSCRIPTION FACTORS.

DNA-Binding Proteins [M0006678]
Proteins which bind to DNA. The family includes proteins which bind to both double- and single-stranded DNA and also includes specific DNA binding proteins in serum which can be used as markers for malignant diseases.

DNA-Dependent Adenosinetriphosphatases [M0083541]

DNA-Directed DNA Polymerase [M0006665]
DNA-dependent DNA polymerases found in bacteria, animal and plant cells. During the replication process, these enzymes catalyze the addition of deoxyribonucleotide residues to the end of a DNA strand in the presence of DNA as template-primer. They also possess exonuclease activity and therefore function in DNA repair. EC 2.7.7.7.

DNA-Directed RNA Polymerases [M0019148]
Enzymes that catalyze DNA template-directed extension of the 3'-end of an RNA strand one nucleotide at a time. They can initiate a chain de novo. In eukaryotes, three forms of the enzyme have been distinguished on the basis of sensitivity to alpha-amanitin, and the type of RNA synthesized. (From Enzyme Nomenclature, 1992).

DNA-Formamidopyrimidine Glycosylase [M0101763]
A DNA repair enzyme that is an N-glycosyl hydrolase with specificity for DNA-containing ring-opened N(7)-methylguanine residues.

DnaB Helicases [M0194644]
A family of DNA helicases that participate in DNA REPLICATION. They assemble into hexameric rings with a central channel and unwind DNA processively in the 5' to 3' direction. DnaB helicases are considered the primary replicative helicases for most prokaryotic organisms.

DnaG (Primase) [M0369437]

Dontisanin [M0463077]

Dopa Decarboxylase [M0006755]
One of the AROMATIC-L-AMINO-ACID DECARBOXYLASES, this enzyme is responsible for the conversion of dopa to dopamine. It is of clinical importance in the treatment of Parkinson's disease. EC 4.1.1.28.

Dopamet [M0474248]

Dopamine and cAMP-Regulated Phosphoprotein 32 [M0120355]
A phosphoprotein that was initially identified as a major target of DOPAMINE activated ADENYLYL CYCLASE in the CORPUS STRIATUM. It regulates the activities of PROTEIN PHOSPHATASE-1 and PROTEIN KINASE A, and it is a key mediator of the biochemical, electrophysiological, transcriptional, and behavioral effects of DOPAMINE.

Dopamine beta-Hydroxylase [M0006758]

Dopamine Plasma Membrane Transport Proteins [M0475608]
Sodium chloride-dependent neurotransmitter symporters located primarily on the PLASMA MEMBRANE of dopaminergic neurons. They remove DOPAMINE from the EXTRACELLULAR SPACE by high affinity reuptake into PRESYNAPTIC TERMINALS and are the target of DOPAMINE UPTAKE INHIBITORS.

Dopamine Sulfotransferase [M0023423]

Dopamine Uptake Complex [M0189592]
A dopamine plasma membrane transporter protein complex located on the membrane of dopaminergic neurons. The complex includes homo-oligomers of the DAT Dopamine Transporter.

Dopegyt [M0371003]

Dornavac [M0372342]

Double-Stranded RNA-Binding Proteins [M0025318]

Double-Stranded Telomere-Binding Proteins [M0194751]

Drosophila melanogaster Proteins [M0385195]

Drosophila Proteins [M0385194]
Proteins that originate from insect species belonging to the genus DROSOPHILA. The proteins from the most intensely studied species of Drosophila, DROSOPHILA MELANOGASTER, are the subject of much interest in the area of MORPHOGENESIS and development.

Droxidopa [M0023229]
A precursor of noradrenaline that is used in the treatment of parkinsonism. The racemic form (DL-threo-3,4-dihydroxyphenylserine) has also been used, and has been investigated in the treatment of orthostatic hypotension. There is a deficit of noradrenaline as well as of dopamine in Parkinson's disease and it has been proposed that this underlies the sudden transient freezing seen usually in advanced disease. Administration of DL-threo-3,4-dihydroxyphenylserine has been claimed to result in an improvement in this phenomenon but controlled studies have failed to demonstrate improvement. (Reynolds JEF(Ed): Martindale: The Extra Pharmacopoeia (electronic version). Micromedex, Inc, Englewood, CO, 1995)

Droxidopa, (DL-Tyr)-Isomer [M0331216]

DRTF1a Transcription Factor [M0188995]

DRTF1b Transcription Factor [M0188996]

DRTF1c Transcription Factor [M0188997]

durabronchal [M0447117]

Dynacil [M0482929]

Dynamin I [M0171123]
A subtype of dynamin found primarily in the NEURONS of the brain.

Dynamin II [M0171124]
A subtype of dynamin found ubiquitously expressed in a variety of tissues.

Dynamin III [M0171122]
A subtype of dynamin found expressed exclusively in the testis, lung and brain.

Dynamins [M0171126]
A family of high molecular weight GTP phosphohydrolases that play a direct role in vesicle transport. They associate with microtubule bundles (MICROTUBULES) and are believed to produce mechanical force via a process linked to GTP hydrolysis. This enzyme was formerly listed as EC 3.6.1.50.

Dynein ATPase [M0006907]
A structural protein which forms the arms on the microtubule doublets of cilia and flagella. In the presence of divalent cations, dynein catalyzes the hydrolysis of ATP. This hydrolysis plays an important functional role in the motility process. This enzyme was formerly listed as EC 3.6.1.33.

Dynorphin (1-17) [M0006909]

Dynorphins [M0006908]
A class of opioid peptides including dynorphin A, dynorphin B, and smaller fragments of these peptides. Dynorphins prefer kappa-opioid receptors (RECEPTORS, OPIOID, KAPPA) and have been shown to play a role as central nervous system transmitters.

Dystroglycans [M0197676]
Dystrophin-associated proteins that play role in the formation of a transmembrane link between laminin-2 and DYSTROPHIN. Both the alpha and the beta subtypes of dystroglycan originate via POST-TRANSLATIONAL PROTEIN PROCESSING of a single precursor protein.

Dystrophin [M0024706]
A muscle protein localized in surface membranes which is the product of the Duchenne/Becker muscular dystrophy gene. Individuals with Duchenne muscular dystrophy usually lack dystrophin completely while those with Becker muscular dystrophy have dystrophin of an altered size. It shares features with other cytoskeletal proteins such as SPECTRIN and alpha-actinin but the precise function of dystrophin is not clear. One possible role might be to preserve the integrity and alignment of the plasma membrane to the myofibrils during muscle contraction and relaxation. MW 400 kDa.

Dystrophin-Associated Glycoprotein 1 [M0454544]

Dystrophin-Associated Protein Complex [M0463322]
A macromolecular complex of proteins that includes DYSTROPHIN and DYSTROPHIN-ASSOCIATED PROTEINS. It plays a structural role in the linking the CYTOSKELETON to the EXTRACELLULAR MATRIX.

Dystrophin-Associated Proteins [M0463328]
A group of proteins that associate with DYSTROPHIN at the CELL MEMBRANE to form the DYSTROPHIN-ASSOCIATED PROTEIN COMPLEX.

E Coli Transcription Termination Factor [M0019037]

E-Cadherins [M0024235]

E-Selectin [M0028429]
Cell adhesion molecule and CD antigen that mediates neutrophil, monocyte, and memory T-cell adhesion to cytokine-activated endothelial cells. E-selectin recognizes sialylated carbohydrate groups related to the Lewis X or Lewis A family.

E1A-Associated p300 Protein [M0478327]
A member of the p300-CBP transcription factors that was originally identified as a binding partner for ADENOVIRUS E1A PROTEINS.

E2F Transcription Factors [M0189005]
A family of basic helix-loop-helix transcription factors that control expression of a variety of GENES involved in CELL CYCLE regulation. E2F transcription factors typically form heterodimeric complexes with TRANSCRIPTION FACTOR DP1 or transcription factor DP2, and they have N-terminal DNA binding and dimerization domains. E2F transcription factors can act as mediators of transcriptional repression or transcriptional activation.

E2F1 Transcription Factor [M0188999]
An E2F transcription factor that interacts directly with RETINOBLASTOMA PROTEIN and CYCLIN A and activates GENETIC TRANSCRIPTION required for CELL CYCLE entry and DNA synthesis. E2F1 is involved in DNA REPAIR and APOPTOSIS.

E2F2 Transcription Factor [M0224487]
An E2F transcription factor that interacts directly with RETINOBLASTOMA PROTEIN and CYCLIN A. E2F2 activates GENETIC TRANSCRIPTION required for CELL CYCLE entry and DNA synthesis.

E2F3 Transcription Factor [M0477184]
An E2F transcription factor that interacts directly with RETINOBLASTOMA PROTEIN and CYCLIN A. E2F3 regulates GENETIC TRANSCRIPTION required for CELL CYCLE entry and DNA synthesis.

E2F3a Transcription Factor [M0477198]

E2F3b Transcription Factor [M0477199]

E2F4 Transcription Factor [M0239285]
An E2F transcription factor that represses GENETIC TRANSCRIPTION required for CELL CYCLE entry and DNA synthesis. E2F4 recruits chromatin remodeling factors indirectly to target gene PROMOTER REGIONS through RETINOBLASTOMA LIKE PROTEIN P130 and RETINOBLASTOMA LIKE PROTEIN P107.

E2F5 Transcription Factor [M0477186]
An E2F transcription factor that represses GENETIC TRANSCRIPTION required for CELL CYCLE entry and DNA synthesis. E2F5 recruits chromatin remodeling factors indirectly to target gene promoters through RETINOBLASTOMA LIKE PROTEIN P130.

E2F6 Transcription Factor [M0477187]
An E2F transcription factor that represses GENETIC TRANSCRIPTION required for CELL CYCLE entry and DNA synthesis. E2F6 recruits chromatin remodeling factors directly to target gene promoters and lacks the transactivation domain responsible for binding to the retinoblastoma family of tumor suppressors.

E2F7 Transcription Factor [M0477188]
An E2F transcription factor that represses GENETIC TRANSCRIPTION required for CELL CYCLE entry and DNA synthesis. E2F7 has two separate DNA-binding domains and binds to DNA independently of a dimerization partner.

EAC [M0432616]

Early Growth Response Protein 1 [M0481740]
An early growth response transcription factor that has been implicated in regulation of CELL PROLIFERATION and APOPTOSIS.

Early Growth Response Protein 2 [M0158412]
An early growth response transcription factor that controls the formation of the MYELIN SHEATH around peripheral AXONS by SCHWANN CELLS. Mutations in EGR2 transcription factor have been associated with HEREDITARY MOTOR AND SENSORY NEUROPATHIES such as CHARCOT-MARIE-TOOTH DISEASE.

Early Growth Response Protein 3 [M0190440]
An early growth response transcription factor that is essential for the development of MUSCLE SPINDLES.

Early Growth Response Transcription Factors [M0481739]
A family of transcription factors that are induced by GROWTH FACTORS and contain a highly conserved DNA-binding domain composed of three ZINC FINGER MOTIFS.

Echinomycin [M0006965]
A cytotoxic polypeptide quinoxaline antibiotic isolated from Streptomyces echinatus that binds to DNA and inhibits RNA synthesis.

Ecto-NAD+ Glycohydrolase [M0077250]

Ecto-Phosphoprotein Phosphatase [M0016692]

Ectodysplasin A, Isoform 1 [M0492659]
An ectodysplasin isoform with specificity for the EDAR RECEPTOR.

Ectodysplasin A, Isoform 2 [M0492660]
An ectodysplasin isoform with specificity for the XEDAR RECEPTOR.

Ectodysplasins [M0284074]
Transmembrane proteins belonging to the tumor necrosis factor superfamily that play an essential role in the normal development of several ectodermally derived organs. Several isoforms of the ectodysplasins exist due to multiple ALTERNATIVE SPLICING of the MRNA for the protein. The isoforms ectodysplasin A1 and ectodysplasin A2 are considered biologically active and each bind distinct ECTODYSPLASIN RECEPTORS. Genetic mutations that result in loss of function of ectodysplasin result in ECTODERMAL DYSPLASIA 1, ANHIDROTIC.

Ectosialyltransferase [M0019821]

Edar Receptor [M0492712]
A ectodysplasin receptor subtype that is specific for ECTODYSPLASIN A1. It signals via the specific signaling adaptor EDAR-ASSOCIATED DEATH DOMAIN PROTEIN. Loss of function of the edar receptor is associated with AUTOSOMAL RECESSIVE ANHIDROTIC ECTODERMAL DYSPLASIA and ECTODERMAL DYSPLASIA 3, ANHIDROTIC.

Edar-Associated Death Domain Protein [M0492748]
A tumor necrosis factor receptor-associated factor that acts as a specific signaling adaptor protein for the EDAR RECEPTOR and plays an important role in ectodermal development. It binds to edar receptor via its C-terminal death domain region and to other specific TNF receptor-associated factors via its N-terminal domain. Loss of function of edar-associated death domain protein is associated with AUTOSOMAL RECESSIVE ANHIDROTIC ECTODERMAL DYSPLASIA.

Edeine [M0007050]
Basic peptide antibiotic from Bacillus brevis. It exhibits broad-spectrum antibacterial activity and inhibits bacterial DNA synthesis.

eEF-Tu [M0016220]

Eel Calcitonin [M0003146]

Eferox [M0463499]

Eflornithine [M0000787]
An inhibitor of ornithine decarboxylase, the rate limiting enzyme of the polyamine biosynthetic pathway.

Eflornithine Hydrochloride [M0330745]

EG2 Antigen [M0456416]
Antigen detected when eosinophil granules are released.

Egg Proteins [M0007121]
Proteins which are found in eggs (OVA) from any species.

Egg Proteins, Dietary [M0023708]
Proteins found in eggs which are consumed as a food.

Egg Shell Proteins [M0007122]

Egg White Proteins [M0007123]

Egg White Proteins, Dietary [M0023709]

EIF-(iso)4F [M0114951]
An isoform of eukaryotic initiation factor-4F found in plants.

eIF-2 Kinase [M0029534]
A dsRNA-activated cAMP-independent protein serine/threonine kinase that is induced by interferon. In the presence of dsRNA and ATP, the kinase autophosphorylates on several serine and threonine residues. The phosphorylated enzyme catalyzes the phosphorylation of the alpha subunit of EUKARYOTIC INITIATION FACTOR-2, leading to the inhibition of protein synthesis.

Elafin [M0485533]
A secretory proteinase inhibitory protein that was initially purified from human SKIN. It is found in a variety mucosal secretions and is present at high levels in SPUTUM. Elafin may play a role in the innate immunity (IMMUNITY, INNATE) response of the LUNG.

Elastase I [M0015810]

Electron Transport Chain Complex Proteins [M0447484]
A complex of enzymes and PROTON PUMPS located on the inner membrane of the MITOCHONDRIA and in bacterial membranes. The protein complex provides energy in the form of an electrochemical gradient, which may be used by either MITOCHONDRIAL PROTON-TRANSLOCATING ATPASES or BACTERIAL PROTON-TRANSLOCATING ATPASES.

Electron Transport Complex I [M0205105]
A flavoprotein and iron sulfur-containing oxidoreductase complex that catalyzes the conversion of UBIQUINONE to ubiquinol. In MITOCHONDRIA the complex also couples its reaction to the transport of PROTONS across the internal mitochondrial membrane. The NADH DEHYDROGENASE component of the complex can be isolated and is listed as EC 1.6.99.3.

Electron Transport Complex II [M0079129]
A flavoprotein oxidase complex that contains iron-sulfur centers. It catalyzes the oxidation of SUCCINATE to FUMARATE and couples the reaction to the reduction of UBIQUINONE to ubiquinol.

Electron Transport Complex III [M0022210]
A multisubunit enzyme complex that contains CYTOCHROME B GROUP; CYTOCHROME C1; and iron-sulfur centers. It catalyzes the oxidation of ubiquinol to UBIQUINONE, and transfers the electrons to CYTOCHROME C. In MITOCHONDRIA the redox reaction is coupled to the transport of PROTONS across the inner mitochondrial membrane.

Electron Transport Complex IV [M0005587]
A multisubunit enzyme complex containing CYTOCHROME A GROUP; CYTOCHROME A3; two copper atoms; and 13 different protein subunits. It is the terminal oxidase complex of the RESPIRATORY CHAIN and collects electrons that are transferred from the reduced CYTOCHROME C GROUP and donates them to molecular OXYGEN, which is then reduced to water. The redox reaction is simultaneously coupled to the transport of PROTONS across the inner mitochondrial membrane.

Electron-Transferring Flavoproteins [M0112516]
Flavoproteins that serve as specific electron acceptors for a variety of DEHYDROGENASES. They participate in the transfer of electrons to a variety of redox acceptors that occur in the respiratory chain.

Eledoisin [M0007224]
A peptide extracted from the posterior salivary glands of certain small octopi (Eledone spp., Mollusca), or obtained by synthesis. Its actions resemble those of SUBSTANCE P; it is a potent vasodilator and increases capillary permeability. (From Martindale, The Extra Pharmacopoeia, 30th ed, p1364)

Elongation Factor [M0016223]

Elongation Factor 1alpha [M0088232]

Elongation Factor 1beta [M0088233]

Elongation Factor 1delta [M0088226]

Elongation Factor 1gamma [M0224619]

Elspar [M0001817]

Eltroxin [M0463500]

Eltroxine [M0024800]

Emfilermin [M0471288]

Eminase [M0024830]

Emulsion beta-D-Glucosidase [M0002420]

Enalapril [M0007330]
One of the ANGIOTENSIN-CONVERTING ENZYME INHIBITORS that is used to treat hypertension.

Enalapril Maleate [M0331398]

Enalapril-TEVA [M0485302]

Enalaprilat [M0024167]
The active metabolite of ENALAPRIL and a potent intravenously administered angiotensin-converting enzyme inhibitor. It is an effective agent for the treatment of essential hypertension and has beneficial hemodynamic effects in heart failure. The drug produces renal vasodilation with an increase in sodium excretion.

Enalaprilat Anhydrous [M0329455]

Enalaprilat Citrate, Anhydrous [M0329457]

Enalaprilat, (R)-Isomer, Anhydrous [M0329454]

Enantone [M0025475]

Encron [M0474886]

Endo-1,3(4)-beta-Glucanase [M0445569]
An endocellulase with specificity for the hydrolysis of 1,3- or 1,4-linkages in beta-D-glucans. This enzyme specifically acts on sites where reducing glucose residues are substituted at the 3 position.

Endo-1,4-beta Xylanases [M0073473]
Enzymes which catalyze the endohydrolysis of 1,4-beta-D-xylosidic linkages in XYLANS.

Endo-1,4-beta-Xylanase II [M0294560]

Endo-beta-N-Acetylglucosaminidase D [M0025886]

Endo-beta-N-Acetylglucosaminidase F [M0009335]

Endo-beta-N-Acetylglucosaminidase H [M0009336]

Endo-Dextranase [M0006106]

Endobulin [M0025516]

Endocellulases [M0445548]

Endochitinase [M0004104]

Endodeoxyribonuclease BpeI [M0023467]

Endodeoxyribonucleases [M0007404]
A group of enzymes catalyzing the endonucleolytic cleavage of DNA. They include members of EC 3.1.21.-, EC 3.1.22.-, EC 3.1.23.- (DNA RESTRICTION ENZYMES), EC 3.1.24.- (DNA RESTRICTION ENZYMES), and EC 3.1.25.-.

Endogenous Substances Receptors [M0018575]

Endoglucanase A [M0003783]

Endoglucanase C [M0003784]

Endoglucanase E [M0003785]

Endoglucanase I [M0445568]

Endoglucanase IV [M0003787]

Endoglucanase Y [M0003786]

Endoglucuronidase [M0009364]

Endoglycosidases [M0009497]

Endohexosaminidase F [M0025890]

Endohexosaminidase H [M0025884]

Endomucins [M0058738]

Endonuclease AacI [M0023436]

Endonuclease AaeI [M0023437]

Endonuclease AccEBI [M0023438]

Endonuclease Ali12257I [M0023439]

Endonuclease Ali12258I [M0023440]

Endonuclease AliI [M0023441]

Endonuclease Asp52I [M0023468]

Endonuclease BamFI [M0023442]

Endonuclease BamKI [M0023443]

Endonuclease BamNI [M0023444]

Endonuclease BbrI [M0023469]

Endonuclease BnaI [M0023455]

Endonuclease BpeI [M0023470]

Endonuclease Bst1503 [M0023445]

Endonuclease BstI [M0023446]

Endonuclease Cfr32I [M0023472]

Endonuclease ChuI [M0023473]

Endonuclease DdsI [M0023447]

Endonuclease Eco159I [M0023461]

Endonuclease Eco65I [M0023474]

Endonuclease Eco82I [M0023462]

Endonuclease Eco98I [M0023475]

Endonuclease Hin1076III [M0023477]

Endonuclease Hin173I [M0023478]

Endonuclease HinbIII [M0023479]

Endonuclease HinfII [M0023480]

Endonuclease HinJCII [M0023481]

Endonuclease HsuI [M0023482]

Endonuclease LlaCI [M0355436]
An isoschizomer of HindIII from Lactococcus lactis W15.

Endonuclease MkiI [M0023483]

Endonuclease P1 [M0024106]

Endonuclease RsrI [M0023463]

Endonuclease SolI [M0023458]

Endonuclease V [M0445234]

Endonuclease VIII [M0073431]

Endonucleases [M0007421]
Enzymes that catalyze the hydrolysis of the internal bonds and thereby the formation of polynucleotides or oligonucleotides from ribo- or deoxyribonucleotide chains. EC 3.1.-.

Endopeptidase Clp [M0157927]
An ATP-dependent protease found in prokaryotes, CHLOROPLASTS, and MITOCHONDRIA. It is a soluble multisubunit complex that plays a role in the degradation of many abnormal proteins.

Endopeptidase K [M0028715]
An enzyme that catalyzes the hydrolysis of keratin, and of other proteins with subtilisin-like specificity. It hydrolyses peptide amides. Endopeptidase K is from the mold Tritirachium album Limber. (Enzyme Nomenclature, 1992) EC 3.4.21.64.

Endopeptidases [M0016230]
A subclass of PEPTIDE HYDROLASES that catalyze the internal cleavage of PEPTIDES or PROTEINS.

Endopolygalacturonase [M0017188]

Endoribonucleases [M0007423]
A family of enzymes that catalyze the endonucleolytic cleavage of RNA. It includes EC 3.1.26.-, EC 3.1.27.-, EC 3.1.30.-, and EC 3.1.31.-.

Endorphenyl [M0333706]

Endorphins [M0007424]
One of the three major groups of endogenous opioid peptides. They are large peptides derived from the PRO-OPIOMELANOCORTIN precursor. The known members of this group are alpha-, beta-, and gamma-endorphin. The term endorphin is also sometimes used to refer to all opioid peptides, but the narrower sense is used here; OPIOID PEPTIDES is used for the broader group.

Endostatins [M0271306]
Angiostatic proteins that are formed from proteolytic cleavage of COLLAGEN TYPE XVIII.

Endothelial Growth Factor Receptor [M0134921]

Endothelin-1 [M0028780]
A 21-amino acid peptide produced in a variety of tissues including endothelial and vascular smooth-muscle cells, neurons and astrocytes in the central nervous system, and endometrial cells. It acts as a modulator of vasomotor tone, cell proliferation, and hormone production. (N Eng J Med 1995;333(6):356-63)

Endothelin-2 [M0028781]
A 21-amino acid peptide produced predominantly within the kidney and intestine, with smaller amounts produced in the myocardium, placenta, and uterus, but the cells of origin are not clear. Endothelin-2 has no unique physiologic functions, as compared with endothelin-1. (N Eng J Med 1995;333(6):356-63)

Endothelin-3 [M0028782]
A 21-amino acid peptide that circulates in the plasma, but its source is not known. Endothelin-3 has been found in high concentrations in the brain and may regulate important functions in neurons and astrocytes, such as proliferation and development. It also is found throughout the gastrointestinal tract and in the lung and kidney. (N Eng J Med 1995;333(6):356-63)

Endothelins [M0024788]
21-Amino-acid peptides produced by vascular endothelial cells and functioning as potent vasoconstrictors. The endothelin family consists of three members, ENDOTHELIN-1; ENDOTHELIN-2; and ENDOTHELIN-3. All three peptides contain 21 amino acids, but vary in amino acid composition. The three peptides produce vasoconstrictor and pressor responses in various parts of the body. However, the quantitative profiles of the pharmacological activities are considerably different among the three isopeptides.

Enisyl [M0012837]

Enkephalin Receptor [M0018581]

Enkephalin, Ala(2)-MePhe(4)-Gly(5)- [M0111607]
An enkephalin analog that selectively binds to the MU OPIOID RECEPTOR. It is used as a model for drug permeability experiments.

Enkephalin, D-Penicillamine (2,5)- [M0328765]
A disulfide opioid pentapeptide that selectively binds to the DELTA OPIOID RECEPTOR. It possesses antinociceptive activity.

Enkephalin, Leucine [M0007454]
One of the endogenous pentapeptides with morphine-like activity. It differs from MET-ENKEPHALIN in the LEUCINE at position 5. Its first four amino acid sequence is identical to the tetrapeptide sequence at the N-terminal of BETA-ENDORPHIN.

Enkephalin, Leucine-2-Alanine [M0024921]
A delta-selective opioid (ANALGESICS, OPIOID). It can cause transient depression of mean arterial blood pressure and heart rate.

Enkephalin, Methionine [M0007455]
One of the endogenous pentapeptides with morphine-like activity. It differs from LEU-ENKEPHALIN by the amino acid METHIONINE in position 5. Its first four amino acid sequence is identical to the tetrapeptide sequence at the N-terminal of BETA-ENDORPHIN.

Enkephalins [M0007456]
One of the three major families of endogenous opioid peptides. The enkephalins are pentapeptides that are widespread in the central and peripheral nervous systems and in the adrenal medulla.

Enoyl-(Acyl-Carrier Protein) Reductase (NADPH, B-Specific) [M0081135]
An enzyme that catalyzes the oxidation of acyl-[acyl-carrier protein] to trans-2,3-dehydroacyl-[acyl-carrier protein] in the fatty acid biosynthesis pathway. It has a preference for acyl derivatives with carbon chain length from 4 to 16.

Enoyl-(Acyl-Carrier-Protein) Reductase (NADH) [M0073480]
An NAD-dependent enzyme that catalyzes the oxidation of acyl-[acyl-carrier protein] to trans-2,3-dehydroacyl-[acyl-carrier protein]. It has a preference for acyl groups with a carbon chain length between 4 to 16.

Enoyl-CoA Hydratase [M0007457]
An enzyme that catalyzes reversibly the hydration of unsaturated fatty acyl-CoA to yield beta-hydroxyacyl-CoA. It plays a role in the oxidation of fatty acids and in mitochondrial fatty acid synthesis, has broad specificity, and is most active with crotonyl-CoA. EC 4.2.1.17.

Enterobactin [M0007475]
An iron-binding cyclic trimer of 2,3-dihydroxy-N-benzoyl-L-serine. It is produced by E COLI and other enteric bacteria.

Enteroglucagons [M0496329]

Enteropeptidase [M0007484]
A specialized proteolytic enzyme secreted by intestinal cells. It converts TRYPSINOGEN into its active form TRYPSIN by removing the N-terminal peptide. EC 3.4.21.9.

env Glycoproteins [M0024062]

Enviomycin [M0007499]
Cyclic basic peptide related to VIOMYCIN. It is isolated from an induced mutant of Streptomyces griseoverticillatus var. tuberacticus and acts as an antitubercular agent with less ototoxicity than tuberactinomycin.

Enzyme Precursors [M0007521]
Physiologically inactive substances that can be converted to active enzymes.

Enzymes, Immobilized [M0007530]
Enzymes which are immobilized on or in a variety of water-soluble or water-insoluble matrices with little or no loss of their catalytic activity. Since they can be reused continuously, immobilized enzymes have found wide application in the industrial, medical and research fields.

Eosinophil Cationic Protein [M0456415]
One of several basic proteins released from EOSINOPHIL cytoplasmic granules. Eosinophil cationic protein is a 21-kDa cytotoxic peptide with a pI of 10.9. Although eosinophil cationic protein is considered a member of the RNAse A superfamily of proteins, it has only limited RNAse activity.

Eosinophil Granule Proteins [M0069643]
Proteins found in EOSINOPHIL granules. They are primarily basic proteins that play a role in host defense and the proinflammatory actions of activated eosinophils.

Eosinophil Major Basic Protein [M0069649]
One of several basic proteins released from EOSINOPHIL cytoplasmic granules. Eosinophil major basic protein is a 14-kDa cytotoxic peptide with a pI of 10.9. In addition to its direct cytotoxic effects, it stimulates the release of variety of INFLAMMATION MEDIATORS.

Eosinophil Peroxidase [M0105781]
A 66-kDa peroxidase found in EOSINOPHIL granules. Eosinophil peroxidase is a cationic protein with a pI of 10.8 and is comprised of a heavy chain subunit and a light chain subunit. It possesses cytotoxic activity towards BACTERIA and other organisms, which is attributed to its peroxidase activity.

Eosinophil-Derived Neurotoxin [M0166890]
A 19-kDa cationic peptide found in EOSINOPHIL granules. Eosinophil-derived neurotoxin is a RIBONUCLEASE and may play a role as an endogenous antiviral agent.

Eph Ligand Family 2 Protein, Mammalian [M0244281]

Ephrin A Receptors [M0409929]

Ephrin B Receptors [M0296980]

Ephrin-A1 [M0181712]
An ephrin that was originally identified as the product of an early response gene induced by TUMOR NECROSIS FACTORS. It is linked to the CELL MEMBRANE via a GLYCOINOSITOL PHOSPHOLIPID MEMBRANE ANCHOR and binds EPHA2 RECEPTOR with high affinity. During embryogenesis high levels of ephrin-A1 are expressed in LUNG; KIDNEY; SALIVARY GLANDS; and INTESTINE.

Ephrin-A2 [M0296966]
A GLYCOINOSITOL PHOSPHOLIPID MEMBRANE ANCHOR-containing ephrin with a high affinity for the EPHA3 RECEPTOR. Early in embryogenesis it is expressed at high levels in the MESENCEPHALON; SOMITES; branchial arches, and LIMB BUD.

Ephrin-A3 [M0242150]
A GLYCOINOSITOL PHOSPHOLIPID MEMBRANE ANCHOR containing ephrin with a high affinity for the EPHA3 RECEPTOR; EPHA5 RECEPTOR; EPHA6 RECEPTOR; EPHA7 RECEPTOR; and EPHA8 RECEPTOR. It is found primarily in NERVE TISSUE.

Ephrin-A4 [M0242157]
A GLYCOINOSITOL PHOSPHOLIPID MEMBRANE ANCHOR containing ephrin found in variety of adult tissue such as KIDNEY; LUNG; COLON and OVARY. During embryonic development, ephrin-A4 is expressed in the HIPPOCAMPUS and CEREBRAL CORTEX. It binds preferentially to ephA receptors (EPH FAMILY RECEPTORS) with the exception of the EPHA1 RECEPTOR.

Ephrin-A5 [M0296978]
A GLYCOINOSITOL PHOSPHOLIPID MEMBRANE ANCHOR containing ephrin found in developing tectum. It has been shown to mediate the bundling of cortical axons and repel the axonal growth of retinal ganglia axons. It is found in a variety of adult tissues of BRAIN; HEART; and KIDNEY.

Ephrin-B1 [M0235725]
A transmembrane domain containing ephrin that is specific for EPHB1 RECEPTOR; EPHB2 RECEPTOR and EPHB3 RECEPTOR. It is widely expressed in a variety of developing and adult tissues.

Ephrin-B2 [M0256945]
A transmembrane domain containing ephrin that binds with high affinity to EPHB1 RECEPTOR; EPHB3 RECEPTOR; and EPHB4 RECEPTOR. Expression of ephrin-B2 occurs in a variety of adult tissues. During embryogenesis, high levels of ephrin-B2 is seen in the PROSENCEPHALON; RHOMBENCEPHALON; developing SOMITES; LIMB BUD; and bronchial arches.

Ephrin-B3 [M0286807]
A transmembrane domain containing ephrin. Although originally found to be specific for the EPHB3 RECEPTOR it has since been shown to bind a variety of EPH FAMILY RECEPTORS. During embryogenesis ephrin-B3 is expressed at high levels in the ventral neural tube. In adult tissues, it is found primarily in the BRAIN and HEART.

Ephrins [M0409594]
Signaling proteins that are ligands for the EPH FAMILY RECEPTORS. They are membrane-bound proteins that are attached to the CELL MEMBRANE either through a GLYCOINOSITOL PHOSPHOLIPID MEMBRANE ANCHOR or through a transmembrane domain. Many of the ephrins are considered important intercellular signaling molecules that control morphogenic changes during embryogenesis.

Epidermal Growth Factor [M0007549]
A 6-kDa polypeptide growth factor initially discovered in mouse submaxillary glands. Human epidermal growth factor was originally isolated from urine based on its ability to inhibit gastric secretion and called urogastrone. EPIDERMAL GROWTH FACTOR exerts a wide variety of biological effects including the promotion of proliferation and differentiation of mesenchymal and epithelial cells.

Epidermolytic Toxins [M0008010]

Epididymal Secretory Proteins [M0148666]
Proteins secreted by the epididymal epithelium. These proteins are both tissue- and species-specific. They are important molecular agents in the process of sperm maturation.

Epimerases [M0029702]

Epithelial Sodium Channel [M0254795]
An AMILORIDE-sensitive sodium channel found on salt-reabsorbing EPITHELIAL CELLS that line the distal NEPHRON, the distal COLON; SALIVARY DUCTS; SWEAT GLANDS; and the LUNG. It plays a critical role in the control of sodium balance, BLOOD VOLUME, and BLOOD PRESSURE.

Epithelial Sodium Channel, alpha Subunit [M0484144]

Epithelial Sodium Channel, beta Subunit [M0484145]

Epithelial Sodium Channel, delta Subunit [M0484148]

Epithelial Sodium Channel, gamma Subunit [M0484146]

Epoetin Alfa [M0028770]
This recombinant erythropoetin, a 165-amino acid glycoprotein (about 62% protein and 38% carbohydrate), regulates red blood cell production. Epoetin alfa is produced by Chinese hamster ovary cells into which the human erythropoetin gene has been inserted. (USP Dictionary of USAN and International Drug Names, 1996).

Epogen [M0373310]

Epothilone Polyketide Synthase [M0357204]

Epoxide Hydrolases [M0007610]
Enzymes that catalyze reversibly the formation of an epoxide or arene oxide from a glycol or aromatic diol, respectively. EC 3.3.2.3.

Eprex [M0028767]

Epsamon [M0351466]

Epsikapron [M0351465]

epsilon-Casein [M0003591]

epsilon-Crystallins [M0005395]
A group of crystallins that have been found in the lens (LENS, CRYSTALLINE) of DUCKS and CROCODILES. They are inactivated forms of the B chain subunit of lactate dehydrogenase.

epsilon-Globin [M0009286]

Epsilon-Polylysine [M0017205]

epsilon-Sarcoglycan [M0284713]

Epstein-Barr Virus Nuclear Antigens [M0028753]
Nuclear antigens encoded by VIRAL GENES found in HUMAN HERPESVIRUS 4. At least six nuclear antigens have been identified.

Equilibrative Nucleoside Transport Proteins [M0283370]
A class of sodium-independent nucleoside transporters that mediate the facilitative transport of NUCLEOSIDES.

Equilibrative Nucleoside Transporter 1 [M0270202]
A subtype of equilibrative nucleoside transporter proteins that is sensitive to inhibition by 4-nitrobenzylthioinosine.

Equilibrative-Nucleoside Transporter 2 [M0285219]
A subtype of equilibrative nucleoside transporter proteins that is insensitive to inhibition by 4-nitrobenzylthioinosine.

Erabutoxins [M0007648]
Toxins isolated from the venom of Laticauda semifasciata, a sea snake (Hydrophid); immunogenic, basic polypeptides of 62 amino acids, folded by four disulfide bonds, block neuromuscular end-plates irreversibly, thus causing paralysis and severe muscle damage; they are similar to Elapid neurotoxins.

ERbetacx [M0265133]

Erwinase [M0001816]

Eryhem [M0010130]

erythro-3,4-Dihydroxyphenylserine [M0023231]

Erythrocruorins [M0007692]
High molecular weight (1,500,000 to 3,000,000) hemoglobins found in the plasma of many polychete and oligochete annelid worms and various mollusks. They bind one mole of oxygen per heme and function as oxygen carriers.

Erythrocyte Band 4.5 Protein [M0014035]

Erythrocyte Lactate Transporters [M0110478]

Erythrocyte protein p55 [M0075050]

Erythroid-Specific DNA-Binding Factors [M0166803]
A group of transcription factors that were originally described as being specific to ERYTHROID CELLS.

Erythromycin Polyketide Synthase [M0171384]

Erythropoietin [M0007726]
Glycoprotein hormone, secreted chiefly by the kidney in the adult and the liver in the fetus, that acts on erythroid stem cells of the bone marrow to stimulate proliferation and differentiation.

Erythropoietin, Recombinant [M0028769]
ERYTHROPOIETIN prepared by recombinant DNA technology.

Erythrose Reductase [M0000684]

Escherichia coli Proteins [M0385527]
Proteins obtained from ESCHERICHIA COLI.

Escherichia coli Proton-Translocating ATPase [M0009722]

Esterase 10 [M0090430]

Esterases [M0007764]

Estradiol 17 alpha-Dehydrogenase [M0007778]

Estradiol 17 beta-Dehydrogenase [M0007779]

Estradiol Dehydrogenases [M0007780]
Enzymes that catalyze the oxidation of estradiol at the 17-hydroxyl group in the presence of NAD+ or NADP+ to yield estrone and NADH or NADPH. The 17-hydroxyl group can be in the alpha- or beta-configuration. EC 1.1.1.62

Estrogen Nuclear Receptor [M0018587]

Estrogen Receptor 1 [M0420629]

Estrogen Receptor 2 [M0420631]

Estrogen Receptor alpha [M0280632]
One of the ESTROGEN RECEPTORS that has marked affinity for ESTRADIOL. Its expression and function differs from, and in some ways opposes, ESTROGEN RECEPTOR BETA.

Estrogen Receptor beta [M0265136]
One of the ESTROGEN RECEPTORS that has greater affinity for ISOFLAVONES than ESTROGEN RECEPTOR ALPHA does. There is great sequence homology with ER alpha in the DNA-binding domain but not in the ligand binding and hinge domains.

Estrogen UDP-Glucuronosyltransferase [M0022219]

Estrone Glucuronyltransferase [M0022220]

Ethanolamine Ammonia-Lyase [M0007821]
An enzyme that catalyzes the deamination of ethanolamine to acetaldehyde. EC 4.3.1.7.

Ethanolaminephosphotransferase [M0007822]
An enzyme that catalyzes reversibly the transfer of phosphoethanolamine from CDP-ethanolamine to diacylglycerol to yield phosphatidylethanolamine (cephalin) and CMP. The enzyme is found in the endoplasmic reticulum. EC 2.7.8.1.

Ether-A-Go-Go Potassium Channels [M0230007]
A family of voltage-gated potassium channels that are characterized by long N-terminal and C-terminal intracellular tails. They are named from the Drosophila protein whose mutation causes abnormal leg shaking under ether anesthesia. Their activation kinetics are dependent on extracellular MAGNESIUM and PROTON concentration.

Ethionine [M0007870]
2-Amino-4-(ethylthio)butyric acid. An antimetabolite and methionine antagonist that interferes with amino acid incorporation into proteins and with cellular ATP utilization. It also produces liver neoplasms.

Ethylmorphine-N-Demethylase [M0007913]
A drug-metabolizing enzyme of the hepatic microsomal oxidase system which catalyzes the oxidation of the N-methyl group of ethylmorphine with the formation of formaldehyde.

ets-Domain Protein Elk-1 [M0164561]
A member of the ternary complex family of ets-related transcription factors that is regulated by MITOGEN-ACTIVATED PROTEIN KINASES including JNK MITOGEN-ACTIVATED PROTEIN KINASES; MITOGEN-ACTIVATED PROTEIN KINASE 1; MITOGEN-ACTIVATED PROTEIN KINASE 3; and P38 MITOGEN-ACTIVATED PROTEIN KINASES.

ets-Domain Protein Elk-4 [M0197465]
A member of the ternary complex family of ets-related transcription factors that is regulated by MITOGEN-ACTIVATED PROTEIN KINASES such as EXTRACELLULAR SIGNAL-REGULATED MAP KINASES; and P38 MITOGEN-ACTIVATED PROTEIN KINASES.

Eu-Actinin [M0000277]

Euglobulins [M0019696]

Eukaryotic Initiation Factor-1 [M0024412]
A eukaryotic initiation factor that binds to 40S ribosomal subunits. Although initially considered a "non-essential" factor for eukaryotic transcription initiation, eukaryotic initiation factor-1 is now thought to play an important role in localizing RIBOSOMES at the initiation codon of MRNA.

Eukaryotic Initiation Factor-2 [M0024274]
Eukaryotic initiation factor of protein synthesis. In higher eukaryotes the factor consists of three subunits: alpha, beta, and gamma. As initiation proceeds, eIF-2 forms a ternary complex with Met-tRNAi and GTP.

Eukaryotic Initiation Factor-2, alpha Subunit [M0024275]

Eukaryotic Initiation Factor-2, beta Subunit [M0024276]

Eukaryotic Initiation Factor-2, gamma Subunit [M0024277]

Eukaryotic Initiation Factor-2B [M0328184]
A guanine nucleotide exchange factor that acts to restore EUKARYOTIC INITIATION FACTOR-2 to its GTP bound form.

Eukaryotic Initiation Factor-2B, alpha Subunit [M0331721]

Eukaryotic Initiation Factor-2B, beta Subunit [M0331722]

Eukaryotic Initiation Factor-2B, delta Subunit [M0331723]

Eukaryotic Initiation Factor-2B, epsilon Subunit [M0331724]

Eukaryotic Initiation Factor-2B, gamma Subunit [M0331725]

Eukaryotic Initiation Factor-3 [M0177967]
A multisubunit eukaryotic initiation factor that contains at least 8 distinct polypeptides. It plays a role in recycling of ribosomal subunits to the site of transcription initiation by promoting the dissociation of non-translating ribosomal subunits. It also is involved in promoting the binding of a ternary complex of EUKARYOTIC INITIATION FACTOR-2; GTP; and INITIATOR TRNA to the 40S ribosomal subunit.

Eukaryotic Initiation Factor-3, Subunit 1 [M0420011]

Eukaryotic Initiation Factor-3, Subunit 2 [M0420012]

Eukaryotic Initiation Factor-3, Subunit 3 [M0407774]

Eukaryotic Initiation Factor-3, Subunit 4 [M0303455]

Eukaryotic Initiation Factor-3, Subunit 5 [M0420013]

Eukaryotic Initiation Factor-3, Subunit 6 [M0242820]

Eukaryotic Initiation Factor-3, Subunit 7 [M0420029]

Eukaryotic Initiation Factor-3, Subunit 8 [M0373801]

Eukaryotic Initiation Factor-4A [M0086510]
A component of eukaryotic initiation factor 4F that as an RNA helicase involved in unwinding the secondary structure of the 5' UNTRANSLATED REGION of MRNA. The unwinding facilitates the binding of the 40S ribosomal subunit.

Eukaryotic Initiation Factor-4A1 [M0086506]

Eukaryotic Initiation Factor-4A2 [M0086507]

Eukaryotic Initiation Factor-4A3 [M0350427]

Eukaryotic Initiation Factor-4E [M0138060]
A peptide initiation factor that binds specifically to the 5' MRNA CAP STRUCTURE of MRNA in the CYTOPLASM. It is a component of the trimeric complex EIF4F.

Eukaryotic Initiation Factor-4F [M0114953]
A trimeric peptide initiation factor complex that associates with the 5' MRNA cap structure of RNA (RNA CAPS) and plays an essential role in MRNA TRANSLATION. It is composed of EUKARYOTIC INITIATION FACTOR-4A; EUKARYOTIC INITIATION FACTOR-4E; and EUKARYOTIC INITIATION FACTOR-4G.

Eukaryotic Initiation Factor-4G [M0158342]
A component of eukaryotic initiation factor-4F that is involved in multiple protein interactions at the site of translation initiation. Thus it may serve a role in bringing together various initiation factors at the site of translation initiation.

Eukaryotic Initiation Factor-5 [M0110035]
A eukaryotic initiation factor that interacts with the 40S initiation complex and promotes the hydrolysis of the bound GTP. The hydrolysis of GTP causes the release of EUKARYOTIC INITIATION FACTOR-2 and EUKARYOTIC INITIATION FACTOR-3 from the 40S subunit and the subsequent joining of the 60S ribosomal subunit to the 40S complex to form the functional 80S initiation complex

Eukaryotic Initiation Factors [M0419373]
Peptide initiation factors from eukaryotic organisms. Over twelve factors are involved in PEPTIDE CHAIN INITIATION, TRANSLATIONAL in eukaryotic cells. Many of these factors play a role in controlling the rate of MRNA TRANSLATION.

Eurespiran [M0447197]

Euthyrox [M0463502]

Excitatory Amino Acid Receptor [M0026505]

Excitatory Amino Acid Transporter 1 [M0074564]
A glial type glutamate plasma membrane transporter protein found predominately in ASTROCYTES. It is also expressed in HEART and SKELETAL MUSCLE and in the PLACENTA.

Excitatory Amino Acid Transporter 2 [M0244870]
A glutamate plasma membrane transporter protein found in ASTROCYTES and in the LIVER.

Excitatory Amino Acid Transporter 3 [M0122875]
A neuronal and epithelial type glutamate plasma membrane transporter protein.

Excitatory Amino Acid Transporter 4 [M0476512]
A glutamate plasma membrane transporter protein that is primarily expressed in cerebellar PURKINJE CELLS on postsynaptic DENDRITIC SPINES.

Excitatory Amino Acid Transporter 5 [M0476513]
A glutamate plasma membrane transporter protein that is primarily expressed in the RETINA.

Excitatory Amino Acid Transporter Proteins [M0477141]

Excitatory Amino Acids [M0028199]
Endogenous amino acids released by neurons as excitatory neurotransmitters. Glutamic acid is the most common excitatory neurotransmitter in the brain. Aspartic acid has been regarded as an excitatory transmitter for many years, but the extent of its role as a transmitter is unclear.

Exfoliatin Toxin A [M0008011]

Exfoliatins [M0008012]
Protein exotoxins from Staphylococcus aureus, phage type II, which cause epidermal necrolysis. They are proteins with a molecular weight of 26,000 to 32,000. They cause a condition variously called scaled skin, Lyell or Ritter syndrome, epidermal exfoliative disease, toxic epidermal necrolysis, etc.

Exfoliative Toxin B [M0008013]

Exfoliative Toxins [M0008014]

Exo-beta-D-Glucuronidase [M0009365]

Exo-Oligo-1,6-Glucosidase [M0015260]

Exocellulases [M0445545]

Exodeoxyribonuclease V [M0082759]
An ATP-dependent exodeoxyribonuclease that cleaves in either the 5'- to 3'- or the 3'- to 5'-direction to yield 5'-phosphooligonucleotides. It is primarily found in BACTERIA.

Exodeoxyribonuclease V, alpha Chain [M0448828]

Exodeoxyribonuclease V, beta Chain [M0448830]

Exodeoxyribonuclease V, gamma Chain [M0448829]

Exodeoxyribonucleases [M0008024]
A family of enzymes that catalyze the exonucleolytic cleavage of DNA. It includes members of the class EC 3.1.11 that produce 5'-phosphomonoesters as cleavage products.

Exoglycosidases [M0009498]

Exolipase [M0012544]

Exomuc [M0447200]

Exonucleases [M0008030]
Enzymes that catalyze the release of mononucleotides by the hydrolysis of the terminal bond of deoxyribonucleotide or ribonucleotide chains.

Exopenicillinase [M0016149]

Exopeptidases [M0079942]
A sub-subclass of PEPTIDE HYDROLASES that act only near the ends of polypeptide chains. Exopeptidases are further divided into AMINOPEPTIDASES; EC 3.4.11; DIPEPTIDASES; EC 3.4.13; DIPEPTIDYL PEPTIDASES & tripeptidyl peptidases, EC 3.4.14; peptidyl-dipeptidases, EC 3.4.15; CARBOXYPEPTIDASES; EC 3.4.16 - EC 3.4.18, and omega peptidases, EC 3.4.19. EC 3.4.-.

Exoribonucleases [M0008035]
A family of enzymes that catalyze the exonucleolytic cleavage of RNA. It includes EC 3.1.13.-, EC 3.1.14.-, EC 3.1.15.-, and EC 3.1.16.-. EC 3.1.-

Exportins [M0383378]
A subclass of karyopherins that function specifically to export molecules into the nucleus.

Exteins [M0458491]
The (EXternal proTEIN) sequences flanking INTEINS, which are internal fragments of precursor proteins removed by PROTEIN SPLICING. Concomitantly, as the inteins are excised, the exteins are ligated to form mature proteins.

Extracellular Matrix Glycoprotein Receptors [M0024501]

Extracellular Matrix Proteins [M0024954]
Macromolecular organic compounds that contain carbon, hydrogen, oxygen, nitrogen, and usually, sulfur. These macromolecules (proteins) form an intricate meshwork in which cells are embedded to construct tissues. Variations in the relative types of macromolecules and their organization determine the type of extracellular matrix, each adapted to the functional requirements of the tissue. The two main classes of macromolecules that form the extracellular matrix are: glycosaminoglycans, usually linked to proteins (proteoglycans), and fibrous proteins (e.g., COLLAGEN; ELASTIN; FIBRONECTINS; and LAMININ).

Extracellular Signal-Regulated MAP Kinases [M0027004]
A mitogen-activated protein kinase subfamily that is widely expressed and plays a role in regulation of MEIOSIS; MITOSIS; and post mitotic functions in differentiated cells. The extracellular signal regulated MAP kinases are regulated by a broad variety of CELL SURFACE RECEPTORS and can be activated by certain CARCINOGENS.

Extranase [M0463230]

Extrinsic Plasminogen Activators [M0016993]

Eye Lens Protein [M0005400]

Eye Proteins [M0008099]

F Protein Newcastle Disease Virus [M0022723]

F VIII-vWf [M0022846]

F-Actin [M0456011]

F-Box Proteins [M0446216]
A family of proteins that share the F-BOX MOTIF and are involved in protein-protein interactions. They play an important role in process of protein ubiquition by associating with a variety of substrates and then associating into SCF UBIQUITIN LIGASE complexes. They are held in the ubiquitin-ligase complex via binding to SKP DOMAIN PROTEINS.

F1 Polypeptide (Paramyxovirus) [M0022724]

Fabrol [M0447203]

Factor For Inversion Stimulation Protein [M0089784]
A highly abundant DNA binding protein whose expression is strongly correlated with the growth phase of bacteria. The protein plays a role in regulating DNA topology and activation of RIBOSOMAL RNA transcription. It was originally identified as a factor required for inversion stimulation by the Hin recombinase of SALMONELLA and Gin site-specific recombinase of BACTERIOPHAGE MU.

Factor IX [M0008141]
Storage-stable blood coagulation factor acting in the intrinsic pathway. Its activated form, IXa, forms a complex with factor VIII and calcium on platelet factor 3 to activate factor X to Xa. Deficiency of factor IX results in HEMOPHILIA B (Christmas Disease).

Factor IXa [M0024398]
Activated form of factor IX. This activation can take place via the intrinsic pathway by the action of factor XIa and calcium, or via the extrinsic pathway by the action of factor VIIa, thromboplastin, and calcium. Factor IXa serves to activate factor X to Xa by cleaving the arginyl-leucine peptide bond in factor X.

Factor V [M0008142]
Heat- and storage-labile plasma glycoprotein which accelerates the conversion of prothrombin to thrombin in blood coagulation. Factor V accomplishes this by forming a complex with factor Xa, phospholipid, and calcium (prothrombinase complex). Deficiency of factor V leads to Owren's disease.

Factor Va [M0024391]
Activated form of factor V. It is an essential cofactor for the activation of prothrombin catalyzed by factor Xa.

Factor VII [M0008144]
Heat- and storage-stable plasma protein that is activated by tissue thromboplastin to form factor VIIa in the extrinsic pathway of blood coagulation. The activated form then catalyzes the activation of factor X to factor Xa.

Factor VIIa [M0024390]
Activated form of factor VII. Factor VIIa activates factor X in the extrinsic pathway of blood coagulation.

Factor VIII [M0008146]
Blood-coagulation factor VIII. Antihemophilic factor that is part of the factor VIII/von Willebrand factor complex. Factor VIII is produced in the liver and acts in the intrinsic pathway of blood coagulation. It serves as a cofactor in factor X activation and this action is markedly enhanced by small amounts of thrombin.

Factor VIII Coagulant Antigen [M0008149]

Factor VIII Procoagulant Activity [M0008153]

Factor VIII-Heavy Chain [M0008147]

Factor VIII-Related Antigen [M0022847]

Factor VIIIa [M0024392]
Activated form of factor VIII. The B-domain of factor VIII is proteolytically cleaved by thrombin to form factor VIIIa. Factor VIIIa exists as a non-covalent dimer in a metal-linked (probably calcium) complex and functions as a cofactor in the enzymatic activation of factor X by factor IXa. Factor VIIIa is similar in structure and generation to factor Va.

Factor VIIIC [M0008151]

Factor VIIIR-Ag [M0022852]

Factor VIIIR-RCo [M0022848]

Factor X [M0008154]
Storage-stable glycoprotein blood coagulation factor that can be activated to factor Xa by both the intrinsic and extrinsic pathways. A deficiency of factor X, sometimes called Stuart-Prower factor deficiency, may lead to a systemic coagulation disorder.

Factor Xa [M0024399]
Activated form of factor X that participates in both the intrinsic and extrinsic pathways of blood coagulation. It catalyzes the conversion of prothrombin to thrombin in conjunction with other cofactors.

Factor XI [M0008156]
Stable blood coagulation factor involved in the intrinsic pathway. The activated form XIa activates factor IX to IXa. Deficiency of factor XI is often called hemophilia C.

Factor XIa [M0024393]
Activated form of factor XI. In the intrinsic pathway, Factor XI is activated to XIa by factor XIIa in the presence of cofactor HMWK; (HIGH MOLECULAR WEIGHT KININOGEN). Factor XIa then activates factor IX to factor IXa in the presence of calcium.

Factor XII [M0008158]
Stable blood coagulation factor activated by contact with the subendothelial surface of an injured vessel. Along with prekallikrein, it serves as the contact factor that initiates the intrinsic pathway of blood coagulation. Kallikrein activates factor XII to XIIa. Deficiency of factor XII, also called the Hageman trait, leads to increased incidence of thromboembolic disease.

Factor XIIa [M0024400]
Activated form of factor XII. In the initial event in the intrinsic pathway of blood coagulation, kallikrein (with cofactor HIGH MOLECULAR WEIGHT KININOGEN) cleaves factor XII to XIIa. Factor XIIa is then further cleaved by kallikrein, plasmin, and trypsin to yield smaller factor XII fragments (Hageman-Factor fragments). These fragments increase the activity of prekallikrein to kallikrein but decrease the procoagulant activity of factor XII.

Factor XIII [M0008160]
A fibrin-stabilizing plasma enzyme (TRANSGLUTAMINASES) that is activated by THROMBIN and CALCIUM to form FACTOR XIIIA. It is important for stabilizing the formation of the fibrin polymer (clot) which culminates the coagulation cascade.

Factor XIII A-Chain [M0008161]

Factor XIIIa [M0017881]
Activated form of FACTOR XIII, a transglutaminase, which stabilizes the formation of the fibrin polymer (clot) culminating the blood coagulation cascade.

Factrel [M0012447]

Fanconi Anemia Complementation Group A Protein [M0483788]
A Fanconi anemia complementation group protein that is the most commonly mutated protein in FANCONI ANEMIA. It undergoes PHOSPHORYLATION by PROTEIN KINASE B and forms a complex with FANCC PROTEIN in the CELL NUCLEUS.

Fanconi Anemia Complementation Group C Protein [M0217296]
A Fanconi anemia complementation group protein that regulates the activities of CYTOCHROME P450 REDUCTASE and GLUTATHIONE S-TRANSFERASE. It is found predominately in the CYTOPLASM, but moves to the CELL NUCLEUS in response to FANCE PROTEIN.

Fanconi Anemia Complementation Group D2 Protein [M0383516]
A Fanconi anemia complementation group protein that undergoes mono-ubiquitination by FANCL PROTEIN in response to DNA DAMAGE. Also, in response to IONIZING RADIATION it can undergo PHOSPHORYLATION by ATAXIA TELANGIECTASIA MUTATED PROTEIN. Modified FANCD2 interacts with BRCA2 PROTEIN in a stable complex with CHROMATIN, and it is involved in DNA REPAIR by homologous RECOMBINATION.

Fanconi Anemia Complementation Group E Protein [M0483808]
A Fanconi anemia complementation group protein that interacts with FANCC PROTEIN and FANCD2 PROTEIN. It promotes the accumulation of FANCC protein in the CELL NUCLEUS.

Fanconi Anemia Complementation Group F Protein [M0483789]
A Fanconi anemia complementation group protein. It is an essential component of a nuclear core complex that protects the GENOME against CHROMOSOMAL INSTABILITY. It interacts directly with FANCG PROTEIN and helps stabilize a complex with FANCA PROTEIN and FANCC PROTEIN.

Fanconi Anemia Complementation Group G Protein [M0280192]
A Fanconi anemia complementation group protein that undergoes PHOSPHORYLATION by CDC2 PROTEIN KINASE during MITOSIS. It forms a complex with other FANCONI ANEMIA PROTEINS and helps protect CELLS from DNA DAMAGE by genotoxic agents.

Fanconi Anemia Complementation Group L Protein [M0483809]
An E3 UBIQUITIN LIGASE that plays a key role in the DNA damage response pathway of FANCONI ANEMIA PROTEINS. It is associated with mono-ubiquitination of FANCD2 PROTEIN and the redistribution of FANCD2 to nuclear foci containing BRCA1 PROTEIN.

Fanconi Anemia Complementation Group Proteins [M0217295]
A diverse group of proteins whose genetic MUTATIONS have been associated with the chromosomal instability syndrome FANCONI ANEMIA. Many of these proteins play important roles in protecting CELLS against OXIDATIVE STRESS.

Farnesyl-Diphosphate Farnesyltransferase [M0020401]
The first committed enzyme of the biosynthesis pathway that leads to the production of STEROLS. it catalyzes the synthesis of SQUALENE from FARNESYL PYROPHOSPHATE via the intermediate PRESQUALENE PYROPHOSPHATE. This enzyme is also a critical branch point enzyme in the biosynthesis of ISOPRENOIDS that is thought to regulate the flux of ISOPRENE intermediates through the sterol pathway.

Farnesyltranstransferase [M0204347]
An enzyme that catalyzes the synthesis of geranylgeranyl diphosphate from trans, trans-farnesyl diphosphate and isopentenyl diphosphate.

fas Death-Inducing Signaling Complex Components [M0492984]

Fas Ligand Protein [M0229054]
A transmembrane protein belonging to the tumor necrosis factor superfamily that was originally discovered on cells of the lymphoid-myeloid lineage, including activated T-LYMPHOCYTES and NATURAL KILLER CELLS. It plays an important role in immune homeostasis and cell-mediated toxicity by binding to the FAS RECEPTOR and triggering APOPTOSIS.

Fas-Associated Death Domain Protein [M0245371]
A signal-transducing adaptor protein that associates with TNF RECEPTOR complexes. It contains a death effector domain that can interact with death effector domains found on INITIATOR CASPASES such as CASPASE 8 and CASPASE 10. Activation of CASPASES via interaction with this protein plays a role in the signaling cascade that leads to APOPTOSIS.

Fatty Acid Desaturases [M0446718]
A family of enzymes that catalyze the stereoselective, regioselective, or chemoselective syn-dehydrogenation reactions. They function by a mechanism that is linked directly to reduction of molecular OXYGEN.

Fatty Acid Synthetase Complex [M0008263]

Fatty Acid Transport Proteins [M0283532]
A broad category of membrane transport proteins that specifically transport FREE FATTY ACIDS across cellular membranes. They play an important role in LIPID METABOLISM in CELLS that utilize free fatty acids as an energy source.

Fatty Acid-Binding Proteins [M0075751]
Intracellular proteins that reversibly bind hydrophobic ligands including: saturated and unsaturated FATTY ACIDS; EICOSANOIDS; and RETINOIDS. They are considered a highly conserved and ubiquitously expressed family of proteins that may play a role in the metabolism of LIPIDS.

Fatty Acid-Binding Proteins, Adipocyte-Specific [M0075736]

Fatty Acid-Binding Proteins, Brain-Specific [M0075722]

Fatty Acid-Binding Proteins, Cytosolic-Specific [M0373127]

Fatty Acid-Binding Proteins, Intestinal-Specific [M0075743]

Fatty Acid-Binding Proteins, Liver-Specific [M0075745]

Fatty Acid-Binding Proteins, Myocardial-Specific [M0075739]

Fatty Acid-Binding Proteins, Plasma-Membrane Specific [M0075725]

Fc epsilon RI [M0026488]

Fc epsilon RII [M0026489]

Fe-Zn Superoxide Dismutase [M0020829]

Felypressin [M0008307]
A synthetic analog of lysine vasopressin with a PHENYLALANINE substitution at residue 2. Felypressin is a vasoconstrictor with reduced antidiuretic activity.

Fenclonine [M0015725]
A selective and irreversible inhibitor of tryptophan hydroxylase, a rate-limiting enzyme in the biosynthesis of serotonin (5-HYDROXYTRYPTAMINE). Fenclonine acts pharmacologically to deplete endogenous levels of serotonin.

Fenclonine (L)-Isomer [M0329930]

Fenclonine Hydrobromide [M0329934]

Fenclonine, (D)-Isomer [M0329929]

Ferredoxin Hydrogenase [M0010723]

Ferredoxin I [M0008345]

Ferredoxin II [M0008346]

Ferredoxin III [M0008348]

Ferredoxin-NADP Reductase [M0008344]
An enzyme that catalyzes the oxidation and reduction of FERREDOXIN or ADRENODOXIN in the presence of NADP. EC 1.18.1.2 was formerly listed as EC 1.6.7.1 and EC 1.6.99.4.

Ferredoxin-Nitrite Reductase [M0081222]
An IRON-containing protein that uses siroheme and 4Fe-4S iron-sulfur centers as prosthetic groups. It catalyzes the six-electron oxidation of AMMONIA to nitrite.

Ferredoxins [M0008347]
Iron-containing proteins that transfer electrons, usually at a low potential, to flavoproteins; the iron is not present as in heme. (McGraw-Hill Dictionary of Scientific and Technical Terms, 5th ed)

Ferrichrome [M0008353]
A cyclic peptide consisting of three residues of delta-N-hydroxy-delta-N-acetylornithine. It acts as an iron transport agent in Ustilago sphaerogena.

Ferrihorseradish Peroxidase [M0010546]

Ferritin Heavy Chain [M0496078]

Ferritin Light Chain [M0496079]

Ferritins [M0008355]
Iron-containing proteins that are widely distributed in animals, plants, and microorganisms. Their major function is to store IRON in a nontoxic bioavailable form. Each ferritin molecule consists of ferric iron in a hollow protein shell (APOFERRITINS) made of 24 subunits of various sequences depending on the species and tissue types.

Ferrochelatase [M0008356]
A mitochondrial enzyme found in a wide variety of cells and tissues. It is the final enzyme in the 8-enzyme biosynthetic pathway of HEME. Ferrochelatase catalyzes ferrous insertion into protoporphyrin IX to form protoheme or heme. Deficiency in this enzyme results in ERYTHROPOIETIC PROTOPORPHYRIA.

Ferrous Hemoglobin [M0010131]

Ferroxidase I [M0003927]

Festinex [M0475588]

Fetal Globulins [M0008409]

Fetal Hemoglobin [M0008402]
The major component of hemoglobin in the fetus. This HEMOGLOBIN has two alpha and two gamma polypeptide subunits in comparison to normal adult hemoglobin, which has two alpha and two beta polypeptide subunits. Fetal hemoglobin concentrations can be elevated (usually above 0.5%) in children and adults affected by LEUKEMIA and several types of ANEMIA.

Fetal Proteins [M0008410]

Fetoprotein [M0000764]

FI-6934 [M0373519]

Fiblaferon [M0331822]

Fibril-Associated Collagens [M0369273]
A family of non-fibrillar collagens that interact with FIBRILLAR COLLAGENS. They contain short triple helical domains interrupted by short non-helical domains and do not form into collagen fibrils.

Fibrillar Collagens [M0369274]
A family of structurally related collagens that form the characteristic collagen fibril bundles seen in CONNECTIVE TISSUE.

Fibrin [M0008424]
A protein derived from FIBRINOGEN in the presence of THROMBIN, which forms part of the blood clot.

Fibrin Fibrinogen Degradation Products [M0008426]
Soluble protein fragments formed by the proteolytic action of plasmin on fibrin or fibrinogen. FDP and their complexes profoundly impair the hemostatic process and are a major cause of hemorrhage in intravascular coagulation and fibrinolysis.

Fibrin Foam [M0008427]
A dry artificial sterile sponge of fibrin prepared by clotting with thrombin a foam or solution of fibrinogen. It is used in conjunction with thrombin as a hemostatic in surgery at sites where bleeding cannot be controlled by more common methods. (From Martindale, The Extra Pharmacopoeia, 30th ed, p648)

Fibrin Klebe System Immuno [M0373274]

Fibrin Seal [M0373273]

Fibrin Sealant, Human [M0464876]

Fibrin Tissue Adhesive [M0024100]
An autologous or commercial tissue adhesive containing FIBRINOGEN and THROMBIN. The commercial product is a two component system from human plasma that contains more than fibrinogen and thrombin. The first component contains highly concentrated fibrinogen, FACTOR VIII, fibronectin, and traces of other plasma proteins. The second component contains thrombin, calcium chloride, and antifibrinolytic agents such as APROTININ. Mixing of the two components promotes BLOOD CLOTTING and the formation and cross-linking of fibrin. The tissue adhesive is used for tissue sealing, HEMOSTASIS, and WOUND HEALING.

Fibrinogen [M0008430]
Plasma glycoprotein clotted by thrombin, composed of a dimer of three non-identical pairs of polypeptide chains (alpha, beta, gamma) held together by disulfide bonds. Fibrinogen clotting is a sol-gel change involving complex molecular arrangements: whereas fibrinogen is cleaved by thrombin to form polypeptides A and B, the proteolytic action of other enzymes yields different fibrinogen degradation products.

Fibrinogens, Abnormal [M0023429]
Fibrinogens which have a functional defect as the result of one or more amino acid substitutions in the amino acid sequence of normal fibrinogen. Abnormalities of the fibrinogen molecule may impair any of the major steps involved in the conversion of fibrinogen into stabilized fibrin, such as cleavage of the fibrinopeptides by thrombin, polymerization and cross-linking of fibrin. The resulting dysfibrinogenemias can be clinically silent or can be associated with bleeding, thrombosis or defective wound healing.

Fibrinopeptide A [M0008435]
Two small peptide chains removed from the N-terminal segment of the alpha chains of fibrinogen by the action of thrombin during the blood coagulation process. Each peptide chain contains 18 amino acid residues. In vivo, fibrinopeptide A is used as a marker to determine the rate of conversion of fibrinogen to fibrin by thrombin.

Fibrinopeptide B [M0008436]
Two small peptide chains removed from the N-terminal segment of the beta chains of fibrinogen by the action of thrombin. Each peptide chain contains 20 amino acid residues. The removal of fibrinopeptides B is not required for coagulation.

Fibroblast Growth Factor 1 [M0024768]
A 17-kDa single-chain polypeptide growth factor that plays a significant role in the process of WOUND HEALING and is a potent inducer of PHYSIOLOGIC ANGIOGENESIS. It binds to HEPARIN, which potentiates its biological activity and protects it from proteolysis. The growth factor is an extremely potent inducer of DNA synthesis in a variety of cell types from mesoderm and neuroectoderm lineages, and also has chemotactic and mitogenic activities. It was originally named acidic fibroblast growth factor based upon its chemical properties and to distinguish it from basic fibroblast growth factor (FIBROBLAST GROWTH FACTOR 2).

Fibroblast Growth Factor 10 [M0263998]
A fibroblast growth factor that is a mitogen for KERATINOCYTES. It activates FIBROBLAST GROWTH FACTOR RECEPTOR 2B and is involved in LUNG and limb development.

Fibroblast Growth Factor 2 [M0024770]
A single-chain polypeptide growth factor that plays a significant role in the process of WOUND HEALING and is a potent inducer of PHYSIOLOGIC ANGIOGENESIS. Several different forms of the human protein exist ranging from 18-24 kDa in size due to the use of alternative start sites within the fgf-2 gene. It has a 55 percent amino acid residue identity to FIBROBLAST GROWTH FACTOR 1 and has potent heparin-binding activity. The growth factor is an extremely potent inducer of DNA synthesis in a variety of cell types from mesoderm and neuroectoderm lineages. It was originally named basic fibroblast growth factor based upon its chemical properties and to distinguish it from acidic fibroblast growth factor (FIBROBLAST GROWTH FACTOR 1).

Fibroblast Growth Factor 3 [M0480871]
A fibroblast growth factor that is expressed primarily during development.

Fibroblast Growth Factor 4 [M0174910]
A HEPARIN binding fibroblast growth factor that may play a role in LIMB BUD development.

Fibroblast Growth Factor 5 [M0185905]
A fibroblast growth factor that may play a role in regulation of HAIR FOLLICLE phenotype. Spontaneous mutation of the gene for this protein results in a strain of MICE with abnormally long hair, referred to as angora mice.

Fibroblast Growth Factor 6 [M0480880]
A fibroblast growth factor that was initially identified based on its sequence similarity to FIBROBLAST GROWTH FACTOR 4. It is found in MYOBLASTS and plays an important role in MUSCLE DEVELOPMENT.

Fibroblast Growth Factor 7 [M0168688]
A fibroblast growth factor that is a specific mitogen for EPITHELIAL CELLS. It binds a complex of HEPARAN SULFATE and FIBROBLAST GROWTH FACTOR RECEPTOR 2B.

Fibroblast Growth Factor 8 [M0207326]
A fibroblast growth factor that preferentially activates FIBROBLAST GROWTH FACTOR RECEPTOR 4. It was initially identified as an androgen-induced growth factor and plays a role in regulating growth of human BREAST NEOPLASMS and PROSTATIC NEOPLASMS.

Fibroblast Growth Factor 8b [M0402647]

Fibroblast Growth Factor 9 [M0257580]
A fibroblast growth factor that was originally identified as a mitogen for GLIAL CELLS. It is expressed primarily in NEURONS.

Fibroblast Growth Factor Receptor 2b [M0358477]
An isoform of fibroblast growth factor receptor 2 found mainly in EPITHELIAL CELLS that is activated by FIBROBLAST GROWTH FACTOR 7 and FIBROBLAST GROWTH FACTOR 10.

Fibroblast Growth Factor Receptor 2c [M0355127]

Fibroblast Growth Factor Soluble Receptor 1 [M0204500]

Fibroblast Growth Factors [M0008437]
A family of small polypeptide growth factors that share several common features including a strong affinity for HEPARIN, and a central barrel-shaped core region of 140 amino acids that is highly homologous between family members. Although originally studied as proteins that stimulate the growth of fibroblasts this distinction is no longer a requirement for membership in the fibroblast growth factor family.

Fibroblast Intermediate Conductance Potassium Channel [M0355651]

Fibrogammin [M0478247]

Fibroins [M0008444]
Fibrous proteins secreted by INSECTS and SPIDERS. Generally, the term refers to silkworm fibroin secreted by the silk gland cells of SILKWORMS, Bombyx mori. Spider fibroins are called spidroins or dragline silk fibroins

Fibroins, Spider [M0461835]

Fibronectins [M0008450]
Glycoproteins found on the surfaces of cells, particularly in fibrillar structures. The proteins are lost or reduced when these cells undergo viral or chemical transformation. They are highly susceptible to proteolysis and are substrates for activated blood coagulation factor VIII. The forms present in plasma are called cold-insoluble globulins.

Fibrospum [M0008428]

Ficain [M0008460]
A sulfhydryl proteinase with cysteine at the active site from ficus latex. Preferential cleavage is at tyrosine and phenylalanine residues. EC 3.4.22.3.

Filgrastim [M0028831]
A hematopoietic growth factor which promotes proliferation and maturation of neutrophil granulocytes. Clinically it is effective in decreasing the incidence of febrile neutropenia in patients with non-myeloid malignancies receiving myelosuppressive therapy or in reducing the duration of neutropenia and neutropenia-related clinical sequelae in patients with non-myeloid malignancies undergoing myeloblastive chemotherapy followed by BMT. It has also been used in AIDS patients with CMV retinitis being treated with GANCICLOVIR. (Gelman CR, Rumack BH & Hess AJ (eds): DRUGDEX(R) System. MICROMEDEX, Inc., Englewood, Colorado (Edition expires 11/30/95))

Fimbriae Protein Precusors [M0163780]

Fimbriae Proteins [M0060788]
Proteins that are structural components of bacterial fimbriae (FIMBRIAE, BACTERIAL) or sex pili (PILI, SEX).

Fimbrial Adhesins [M0028183]

Fish Antifreeze Proteins, Type I [M0355985]

Fish Antifreeze Proteins, Type II [M0355986]

Fish Antifreeze Proteins, Type III [M0355987]

Fish Proteins [M0385515]
Proteins obtained from species of fish (FISHES).

Fivasa [M0474826]

FK 33-824 [M0008530]

Flagellin [M0008533]
A protein with a molecular weight of 40,000 isolated from bacterial flagella. At appropriate pH and salt concentration, three flagellin monomers can spontaneously reaggregate to form structures which appear identical to intact flagella.

Flap Endonuclease-1 [M0448833]

Flap Endonucleases [M0228928]
Endonucleases that remove 5' DNA sequences from a DNA structure called a DNA flap. The DNA flap structure occurs in double-stranded DNA containing a single-stranded break where the 5' portion of the downstream strand is too long and overlaps the 3' end of the upstream strand. Flap endonucleases cleave the downstream strand of the overlap flap structure precisely after the first base-paired nucleotide, creating a ligatable nick.

Flavodoxin [M0008548]
A low-molecular-weight (16,000) iron-free flavoprotein containing one molecule of flavin mononucleotide (FMN) and isolated from bacteria grown on an iron-deficient medium. It can replace ferredoxin in all the electron-transfer functions in which the latter is known to serve in bacterial cells.

Flavonoid Sulfotransferase [M0023424]

Flavoproteins [M0008550]

FLICE-Inhibitory Protein Long Form [M0278131]

FLICE-Inhibitory Protein Short Form [M0278132]

Fluimucil [M0000173]

Fluorescent Antinuclear Antibodies [M0001490]

Fluprowit [M0445968]

FMN Reductase [M0073582]
An enzyme that utilizes NADH or NADPH to reduce FLAVINS. It is involved in a number of biological processes that require reduced flavin for their functions such as bacterial bioluminescence. Formerly listed as EC 1.6.8.1

FMRFamide [M0029442]
A molluscan neuroactive peptide which induces a fast excitatory depolarizing response due to direct activation of amiloride-sensitive SODIUM CHANNELS. (From Nature 1995; 378(6558): 730-3)

FMRFamide, (D-Arg)-Isomer [M0329037]

FMRFamide, (D-Met)-Isomer [M0329036]

FMRFamide, (D-Phe)-Isomer [M0329038]

fms Oncogene Product gp120 [M0024880]

fms Oncogene Protein gp120 [M0024881]

fms-Like Tyrosine Kinase 3 [M0190176]
A receptor tyrosine kinase that is involved in HEMATOPOIESIS. It is closely related to FMS PROTO-ONCOGENE PROTEIN and is commonly mutated in acute MYELOID LEUKEMIA.

FO-1561 [M0373888]

Focal Adhesion Kinase 1 [M0142569]
A non-receptor protein tyrosine kinase that is localized to FOCAL ADHESIONS and is a central component of integrin-mediated SIGNAL TRANSDUCTION PATHWAYS. Focal adhesion kinase 1 interacts with PAXILLIN and undergoes PHOSPHORYLATION in response to adhesion of cell surface integrins to the EXTRACELLULAR MATRIX. Phosphorylated p125FAK protein binds to a variety of SH2 DOMAIN and SH3 DOMAIN containing proteins and helps regulate CELL ADHESION and CELL MIGRATION.

Focal Adhesion Kinase 2 [M0251076]
A non-receptor protein-tyrosine kinase that is expressed primarily in the BRAIN; OSTEOBLASTS; and LYMPHOID CELLS. In the CENTRAL NERVOUS SYSTEM focal adhesion kinase 2 modulates ION CHANNEL function and MITOGEN-ACTIVATED PROTEIN KINASES activity.

Focal Adhesion Protein-Tyrosine Kinases [M0480413]
A family of non-receptor, PROLINE-rich protein-tyrosine kinases.

Follicle Stimulating Hormone [M0008869]
A major gonadotropin secreted by the adenohypophysis (PITUITARY GLAND, ANTERIOR). Follicle-stimulating hormone stimulates GAMETOGENESIS and the supporting cells such as the ovarian GRANULOSA CELLS, the testicular SERTOLI CELLS, and LEYDIG CELLS. FSH consists of two noncovalently linked subunits, alpha and beta. Within a species, the alpha subunit is common in the three pituitary glycoprotein hormones (TSH, LH, and FSH), but the beta subunit is unique and confers its biological specificity.

Follicle Stimulating Hormone, beta Subunit [M0117624]
The beta subunit of follicle stimulating hormone. It is a 15-kDa glycopolypeptide. Full biological activity of FSH requires the non-covalently bound heterodimers of an alpha and a beta subunit. Mutation of the FSHB gene causes delayed puberty, or infertility.

Follicle Stimulating Hormone, Human [M0008870]
A major gonadotropin secreted by the human adenohypophysis (PITUITARY GLAND, ANTERIOR). Follicle-stimulating hormone stimulates GAMETOGENESIS and the supporting cells such as the ovarian GRANULOSA CELLS, the testicular SERTOLI CELLS, and the LEYDIG CELLS. FSH consists of two noncovalently linked subunits, alpha and beta. The alpha subunit is common in the three human pituitary glycoprotein hormones (TSH, LH, and FSH), but the beta subunit is unique and confers its biological specificity.

Follistatin [M0157962]
A broadly distributed protein that binds directly to ACTIVINS. It functions as an activin antagonist, inhibits FOLLICLE STIMULATING HORMONE secretion, regulates CELL DIFFERENTIATION, and plays an important role in embryogenesis. Follistatin is a single glycosylated polypeptide chain of approximately 37-kDa and is not a member of the inhibin family (INHIBINS). Follistatin also binds and neutralizes many members of the TRANSFORMING GROWTH FACTOR BETA family.

Follistatin-Like Protein 1 [M0416794]
A secreted HEPARIN-binding glycoprotein of approximately 35 kD, encoded by the FSTL1 or FRP gene. Expression of follistatin-related protein 1 is associated with growth inhibition and CELL DIFFERENTIATION.

Follistatin-Like Protein 3 [M0416793]
A secreted glycoprotein of approximately 28 kD, encoded by the FLRG or FSTL3 gene.

Follistatin-Related Proteins [M0239102]
Broadly distributed glycoproteins that are homologous to the activin-binding protein, FOLLISTATIN. These follistatin-related proteins are encoded by a number of genes.

Follistim [M0211974]

Forkhead Transcription Factors [M0166232]
A subclass of winged helix DNA-binding proteins that share homology with their founding member fork head protein, Drosophila.

Formate Dehydrogenases [M0008757]
Flavoproteins that catalyze reversibly the reduction of carbon dioxide to formate. Many compounds can act as acceptors, but the only physiologically active acceptor is NAD. The enzymes are active in the fermentation of sugars and other compounds to carbon dioxide and are the key enzymes in obtaining energy when bacteria are grown on formate as the main carbon source. They have been purified from bovine blood. EC 1.2.1.2.

Formate-Tetrahydrofolate Ligase [M0008774]
A carbon-nitrogen ligase that catalyzes the formation of 10-formyltetrahydrofolate from formate and TETRAHYDROFOLATE in the presence of ATP. In higher eukaryotes the enzyme also contains METHYLENETETRAHYDROFOLATE DEHYDROGENASE (NADP+) and METHENYLTETRAHYDROFOLATE CYCLOHYDROLASE activity.

Formylmethionyl Peptide [M0014397]

Forssman Antibody [M0465764]

Forteo [M0447534]

Fos B Protein [M0025543]

Fos-Related Antigen-2 [M0218884]
A basic-leucine zipper transcription factor that is closely related to C-FOS PROTEINS. It forms heterodimeric complexes with C-JUN PROTEINS to regulate GENE transcription.

Fosinil [M0482928]

Fosinopril [M0026315]
A phosphinic acid-containing angiotensin-converting enzyme inhibitor that is effective in the treatment of hypertension. It is a prodrug that is converted to its active metabolite fosinoprilat.

Fosinopril Sodium [M0026317]

Fosinopril, (1(S*(R*)),2 alpha,4 alpha)-(D-Pro)-Isomer [M0329308]

Fosinopril, (1(S*(S*)),2 alpha,4 beta)-Isomer [M0329307]

Fozitec [M0482927]

Fragile X Mental Retardation Protein [M0188653]
A RNA-binding protein that is found predominately in the CYTOPLASM. It helps regulate GENETIC TRANSLATION in NEURONS and is absent or under-expressed in FRAGILE X SYNDROME.

Framework Region, Immunoglobulin [M0011116]

Frekatuss [M0447204]

Frizzled Receptors [M0479508]
A family of seven-pass transmembrane cell-surface receptors. They contain an extracellular cysteine-rich domain and are receptors for WNT PROTEINS. Frizzled receptors often couple with HETEROTRIMERIC G PROTEINS and regulate multiple SIGNAL TRANSDUCTION PATHWAYS.

Fructokinases [M0008854]
A class of enzymes that catalyzes the phosphorylation of fructose in the presence of ATP. EC 2.7.1.-.

Fructose 1-Phosphate Aldolase [M0008860]

Fructose-2,6-bisphosphatase [M0105385]

Fructose-Bisphosphatase [M0010334]
An enzyme that catalyzes the conversion of D-fructose 1,6-bisphosphate and water to D-fructose 6-phosphate and orthophosphate. EC 3.1.3.11.

Fructose-Bisphosphate Aldolase [M0008861]
An enzyme of the lyase class that catalyzes the cleavage of fructose 1,6-biphosphate to form dihydroxyacetone phosphate and glyceraldehyde 3-phosphate. The enzyme also acts on (3S,4R)-ketose 1-phosphates. The yeast and bacterial enzymes are zinc proteins. (Enzyme Nomenclature, 1992) E.C. 4.1.2.13.

Fructosemonophosphate Aldolase [M0008862]

Fructuronate Reductase [M0008865]
An enzyme that catalyzes the reversible oxidation of mannonate to fructuronate in the presence of NAD. Also reduces D-tagaturonate to D-altronate. EC 1.1.1.57.

Fucosyl Galactose alpha-N-Acetylgalactosaminyltransferase [M0008876]
An enzyme that catalyzes the transfer of acetylgalactosamine from UDP N-acetylgalactosamine to various 2-fucosylgalactosides as acceptors. EC 2.4.1.40.

Fucosyl SSEA-1 [M0024832]

Fucosyltransferases [M0008877]
Enzymes catalyzing the transfer of fucose from a nucleoside diphosphate fucose to an acceptor molecule which is frequently another carbohydrate, a glycoprotein, or a glycolipid molecule. Elevated activity of some fucosyltransferases in human serum may serve as an indicator of malignancy. The class includes EC 2.4.1.65; EC 2.4.1.68; EC 2.4.1.69; EC 2.4.1.89.

Fujinami Sarcoma Virus P140 gag-fps [M0024041]

Fumarate Hydratase [M0008879]
An enzyme that catalyzes the reversible hydration of fumaric acid to yield L-malic acid. It is one of the citric acid cycle enzymes. EC 4.2.1.2.

Fungal Peptides [M0008889]

Fungal Proteins [M0008890]
Proteins found in any species of fungus.

Furin [M0212390]
A proprotein convertase with specificity for the proproteins of PROALBUMIN; COMPLEMENT 3C; and VON WILLEBRAND FACTOR. It has specificity for cleavage near paired ARGININE residues that are separated by two amino acids.

Fushi Tarazu Transcription Factors [M0454727]
Fushi tarazu transcription factors were originally identified in DROSOPHILA. They are found throughout ARTHROPODS and play important roles in segmentation and CENTRAL NERVOUS SYSTEM development.

Fusion Proteins, bcr-abl [M0024527]
Translation products of a fusion mRNA derived from the breakpoint cluster region (bcr) gene and a cellular abl (c-abl) gene translocated to chromosome 22. The p210(bcr-abl) fusion protein is found in patients with chronic myelogenous leukemia. The p190(bcr-abl) fusion protein is found in patients with acute lymphocytic leukemia. The activation of human c-abl by chromosomal translocation is essentially the same as the activation of murine c-abl by viral translocation in Abelson murine leukemia virus.

Fusion Proteins, gag-fos-fox [M0025546]

Fusion Proteins, gag-mos [M0026146]

Fusion Proteins, gag-onc [M0024043]
General name for the translation products of a fusion mRNA consisting of a gag gene and a viral oncogene (v-onc). These products are thought to have the ability to transform cells.

Fusion Proteins, gag-pol [M0024060]
Polyprotein products of a fused portion of retroviral mRNA containing the gag and pol genes. The polyprotein is synthesized only five percent of the time since pol is out of frame with gag, and is generated by ribosomal frameshifting.

Fusion Proteins, gag-ros [M0024049]

Fusion VP1 Protein [M0022725]

Fx1A Renal Tubular Antigen [M0112812]
A specific preparation of Heymann nephritis antigenic complex.

G Protein-Coupled Inwardly-Rectifying Potassium Channel 1 [M0220391]

G Protein-Coupled Inwardly-Rectifying Potassium Channel 2 [M0214257]

G Protein-Coupled Inwardly-Rectifying Potassium Channel 3 [M0237545]

G Protein-Coupled Inwardly-Rectifying Potassium Channel 4 [M0257192]

G Protein-Coupled Inwardly-Rectifying Potassium Channels [M0451133]
A family of inwardly-rectifying potassium channels that are activated by PERTUSSIS TOXIN sensitive G-PROTEIN-COUPLED RECEPTORS. GIRK potassium channels are primarily activated by the complex of GTP-BINDING PROTEIN BETA SUBUNITS and GTP-BINDING PROTEIN GAMMA SUBUNITS.

G(M1) Ganglioside Activating Factor [M0063211]

G(M2) Activator Protein [M0111676]
An essential cofactor for the degradation of G(M2)GANGLIOSIDE by lysosomal BETA-N-ACETYLHEXOSAMINIDASE. Genetic mutations resulting in loss of G(M2) activator protein are one of the causes of TAY-SACHS DISEASE, AB VARIANT.

G-Actin [M0000300]

G-Box Binding Factors [M0200114]
A family of transcription factors found primarily in PLANTS that bind to the G-box DNA sequence CACGTG or to a consensus sequence CANNTG.

G25K GTP-Binding Protein, Placental Isoform [M0331681]

GA-Binding Protein Transcription Factor [M0191974]
A heterotetrameric transcription factor composed of two distinct proteins. Its name refers to the fact it binds to DNA sequences rich in GUANINE and ADENINE. GA-binding protein integrates a variety of SIGNAL TRANSDUCTION PATHWAYS and regulates expression of GENES involved in CELL CYCLE control, PROTEIN BIOSYNTHESIS, and cellular METABOLISM.

GA-Binding Protein, Alpha Subunit [M0479984]

GA-Binding Protein, Beta Subunit [M0479985]

GABA Plasma Membrane Transport Proteins [M0475613]
A family of plasma membrane neurotransmitter transporter proteins that regulates that extracellular levels of the inhibitory neurotransmitter GAMMA-AMINOBUTYRIC ACID. They differ from GABA RECEPTORS, which signal cellular responses to GAMMA-AMINOBUTYRIC ACID. They control GABA reuptake into PRESYNAPTIC TERMINALS in the CENTRAL NERVOUS SYSTEM through high-affinity sodium-dependent transport.

GABA Transporter 1 [M0073957]

GABA Transporter 2 [M0472742]

GABA Transporter 3 [M0472743]

GABA Transporter 4 [M0476524]

gag Gene Related Protein [M0024054]

gag-myc Fused Protein p110 [M0024042]

Galactokinase [M0008934]
An enzyme that catalyzes reversibly the formation of galactose 1-phosphate and ADP from ATP and D-galactose. Galactosamine can also act as the acceptor. A deficiency of this enzyme results in GALACTOSEMIA. EC 2.7.1.6.

Galactosaminidases [M0008937]

Galactose Dehydrogenases [M0008939]
D-Galactose:NAD(P)+ 1-oxidoreductases. Catalyzes the oxidation of D-galactose in the presence of NAD+ or NADP+ to D-galactono-gamma-lactone and NADH or NADPH. Includes EC 1.1.1.48 and EC 1.1.1.120.

Galactose Oxidase [M0008940]
An enzyme that oxidizes galactose in the presence of molecular oxygen to D-galacto-hexodialdose. It is a copper protein. EC 1.1.3.9.

Galactosidases [M0008944]
A family of galactoside hydrolases that hydrolyze compounds with an O-galactosyl linkage. EC 3.2.1.-.

Galactosylceramidase [M0008946]
An enzyme that hydrolyzes galactose from ceramide monohexosides. Deficiency of this enzyme may cause globoid cell leukodystrophy (LEUKODYSTROPHY, GLOBOID CELL). EC 3.2.1.46.

Galactosyltransferases [M0008948]
Enzymes that catalyze the transfer of galactose from a nucleoside diphosphate galactose to an acceptor molecule which is frequently another carbohydrate. EC 2.4.1.-.

Galanin [M0028382]
A 29-amino acid peptide that is found in both the central and peripheral nervous systems. It inhibits glucose-induced insulin release, hippocampal acetylcholine release, hippocampal glutamate (but not GAMMA-AMINOBUTYRIC ACID) release, and it lowers spinal excitability and firing of locus coeruleus neurons. It stimulates food (fat) intake and growth hormone release upon hypothalamic or i.c.v. injection. (Crit Rev Neurobiol 1993;7(3-4):229-74)

Galanin-Like Peptide [M0366125]
A neuropeptide that is highly homologous to GALANIN. It is produced by proteolytic processing of a larger protein that is unrelated to prepro-galanin and preferentially binds to GALANIN-2 RECEPTOR.

Galectin 1 [M0228480]
A galectin found abundantly in smooth muscle (MUSCLE, SMOOTH) and SKELETAL MUSCLE and many other tissues. It occurs as a homodimer with two 14-kDa subunits.

Galectin 2 [M0228485]
A galectin found preferentially expressed in the gastrointestinal tract. The protein occurs as a homodimer with two 14-kDa subunits.

Galectin 3 [M0157095]
A multifunctional galactin initially discovered as a macrophage antigen that binds to IMMUNOGLOBULIN E, and as 29-35-kDa lectin that binds LAMININ. It is involved in a variety of biological events including interactions with galactose-containing glycoconjugates, cell proliferation, CELL DIFFERENTIATION, and APOPTOSIS.

Galectin 4 [M0125657]
A galectin found in the small and large intestine and the stomach. It occurs as a homodimer with two 36-kDa subunits and is localized to sites of cell adhesion where it may play role in assembly of ADHERENS JUNCTIONS.

Galectins [M0067948]
A class of animal lectins that bind specifically to beta-galactoside in a calcium-independent manner. Members of this class are distiguished from other lectins by the presence of a conserved carbohydrate recognition domain. The majority of proteins in this class bind to sugar molecules in a sulfhydryl-dependent manner and are often referred to as S-type lectins, however this property is not required for membership in this class.

Gamimune [M0025517]

Gamimune N [M0025518]

gamma Catenin [M0112636]
A multi-functional catenin that is highly homologous to BETA CATENIN. Gamma catenin binds CADHERINS and helps link their cytoplasmic tails to ACTIN in the CYTOSKELETON via ALPHA CATENIN. It is also found in DESMOSOMES where it mediates the link between DESMOSOMAL CADHERINS and DESMOPLAKIN.

gamma, gamma-Enolase [M0016709]

gamma-1-Immunoglobulin Heavy Chain [M0011128]

gamma-2a-Immunoglobulin Heavy Chain [M0011129]

gamma-2b-Immunoglobulin Heavy Chain [M0011130]

gamma-Actin [M0000301]

gamma-Aminobutyric Acid [M0008927]
The most common inhibitory neurotransmitter in the central nervous system.

gamma-Aminobutyric Acid, Calcium Salt (2:1) [M0330305]

gamma-Aminobutyric Acid, Hydrochloride [M0330303]

gamma-Aminobutyric Acid, Monolithium Salt [M0330302]

gamma-Aminobutyric Acid, Monosodium Salt [M0330304]

gamma-Aminobutyric Acid, Zinc Salt (2:1) [M0330306]

gamma-Atrial Natriuretic Peptide [M0447905]
The 126-amino acid C-terminal fragment of the ANP precursor, an approximately 150-amino acid polypeptide in a number of species. It is formed by the removal of the N-terminal signal sequence ANP (1-24). This prohormone contains various active ANF sequences.

gamma-Butyrobetaine Dioxygenase [M0072677]
An enzyme that catalyzes the HYDROXYLATION of gamma-butyrobetaine to L-CARNITINE. It is the last enzyme in the biosynthetic pathway of L-CARNITINE and is dependent on alpha-ketoglutarate; IRON; ASCORBIC ACID; and OXYGEN.

gamma-Carboxyglutamate [M0023167]

gamma-Caseins [M0003592]

gamma-Crystallins [M0005396]
A subclass of crystallins that found in the lens (LENS, CRYSTALLINE) of VERTEBRATES. Gamma-crystallins are similar in structure to BETA-CRYSTALLINS in that they both form into a Greek key-like structure. They are composed of monomeric subunits.

gamma-Endorphin [M0028179]
An endogenous opioid peptide derived from BETA-LIPOTROPIN of the pro-opiomelanocortin (POMC) system. It is the 17-amino acid sequence of the N-terminal of BETA-ENDORPHIN and differs from ALPHA-ENDORPHIN by one amino acid (beta-endorphin 1-16).

gamma-Fibrinogen [M0008431]

gamma-Globin [M0009287]

gamma-Globulins [M0008973]
Serum globulins that migrate to the gamma region (most positively charged) upon ELECTROPHORESIS. At one time, gamma-globulins came to be used as a synonym for immunoglobulins since most immunoglobulins are gamma globulins and conversely most gamma globulins are immunoglobulins. But since some immunoglobulins exhibit an alpha or beta electrophoretic mobility, that usage is in decline.

gamma-Glutamyl Hydrolase [M0018076]
Catalyzes the hydrolysis of pteroylpolyglutamic acids in gamma linkage to pterolylmonoglutamic acid and free glutamic acid. EC 3.4.19.9.

gamma-Glutamylcyclotransferase [M0008976]
An enzyme that catalyzes the synthesis of pyroglutamate from a gamma-glutamyl-amino acid, also releasing the free amino acid. The enzyme acts on derivatives of glutamate, 2-aminobutyrate, alanine and glycine. The enzyme has been proposed to have a role in a gamma-glutamyl cycle for amino acid transport into cells in the intestines. EC 2.3.2.4.

gamma-Glutamyltransferase [M0008977]
An enzyme, sometimes called GGT, with a key role in the synthesis and degradation of GLUTATHIONE; (GSH, a tripeptide that protects cells from many toxins). It catalyzes the transfer of the gamma-glutamyl moiety to an acceptor amino acid.

gamma-Lipotropin [M0012606]
A lipotropic peptide that is the N-terminal fragment of beta-lipotropin. It is a peptide of 56 amino acids in humans and 58 amino acids in pigs.

gamma-MSH [M0328126]
An 11-amino acid peptide derived from the N-terminal fragment of pro-opiomelanocortin (POMC). Gamma-MSH stimulates adrenal steroidogenesis and has an regulatory role in the cardiovascular and the renal systems.

gamma-Penicillinase [M0016150]

gamma-Sarcoglycan [M0230890]

gamma-Secretase [M0205215]

gamma-SNAP [M0202546]

gamma-Synuclein [M0159752]
A homolog of ALPHA-SYNUCLEIN that plays a role in neurofilament network integrity. It is overexpressed in a variety of human NEOPLASMS and may be involved in modulating AXON architecture during EMBRYONIC DEVELOPMENT and in the adult. Gamma-Synuclein may also activate SIGNAL TRANSDUCTION PATHWAYS associated with ETS-DOMAIN PROTEIN ELK-1.

gamma-Thrombin [M0021423]

gamma-Transducin [M0023548]

gamma-Tropomyosin [M0022043]

gamma-Tryptases [M0366194]

gamma-Tubulin [M0022141]

gamma1-MSH [M0014151]
The 11-residue peptide that is fully amidated.

gamma2-MSH [M0014152]
The 11-residue peptide that is without amidation.

gamma3-MSH [M0014153]
The 11-residue peptide plus the 12-residue sequence leading to the next dibasic cleavage site at the N-terminal of the joining peptide.

Gammagard [M0025519]

Gammalon [M0369377]

Gammonativ [M0025520]

Gamulin Rh [M0373305]

Ganglioside Galactosyltransferase [M0080291]
Catalyzes the final step in the galactocerebroside biosynthesis pathway.

Ganglioside Hydrolysis Activator Proteins [M0063225]

GAP-43 Protein [M0029597]
A nervous tissue specific protein which is highly expressed in NEURONS during development and NERVE REGENERATION. It has been implicated in neurite outgrowth, long-term potentiation, SIGNAL TRANSDUCTION, and NEUROTRANSMITTER release. (From Neurotoxicology 1994;15(1):41-7) It is also a substrate of PROTEIN KINASE C.

Gargon [M0373341]

Gastric Inhibitory Polypeptide [M0009005]
A gastrointestinal peptide hormone of about 43-amino acids.

Gastric Mucin [M0009008]

Gastrin [M0009014]

Gastrin-Releasing Peptide [M0029527]
Neuropeptide and gut hormone that helps regulate GASTRIC ACID secretion and motor function. Once released from nerves in the antrum of the STOMACH, the neuropeptide stimulates release of GASTRIN from the GASTRIN-SECRETING CELLS.

Gastrins [M0009013]
A family of gastrointestinal peptide hormones that excite the secretion of GASTRIC JUICE. They may also occur in the central nervous system where they are presumed to be neurotransmitters.

GATA Transcription Factors [M0478900]
A family of transcription factors that contain two ZINC FINGER MOTIFS and bind to the DNA sequence (A/T)GATA(A/G).

GATA1 Transcription Factor [M0166784]
A GATA transcription factor that is specifically expressed in hematopoietic lineages and plays an important role in the CELL DIFFERENTIATION of ERYTHROID CELLS and MEGAKARYOCYTES.

GATA2 Transcription Factor [M0192017]
An essential GATA transcription factor that is expressed primarily in HEMATOPOIETIC STEM CELLS.

GATA3 Transcription Factor [M0187089]
A GATA transcription factor that is found predominately in LYMPHOID CELL precursors and has been implicated in the CELL DIFFERENTIATION of HELPER T-CELLS. Haploinsufficiency of GATA3 is associated with HYPOPARATHYROIDISM; SENSORINEURAL HEARING LOSS; and renal anomalies syndrome.

GATA4 Transcription Factor [M0214637]
A GATA transcription factor that is expressed in the MYOCARDIUM of developing heart and has been implicated in the differentiation of CARDIAC MYOCYTES. GATA4 is activated by PHOSPHORYLATION and regulates transcription of cardiac-specific genes.

GATA5 Transcription Factor [M0236194]
A GATA transcription factor that is expressed predominately in SMOOTH MUSCLE CELLS and is involved in the CELL DIFFERENTIATION of CARDIAC MYOCYTES. In the developing heart, GATA5 becomes restricted to the ENDOCARDIUM and regulates transcription of genes such as cardiac TROPONIN C.

GATA6 Transcription Factor [M0236198]
A GATA transcription factor that is expressed predominately in SMOOTH MUSCLE CELLS and regulates vascular smooth muscle CELL DIFFERENTIATION.

GdoI Endonuclease [M0023448]

GDP Kinase [M0015061]

Gelafusal [M0009053]

Gelatin [M0009052]
A product formed from skin, white connective tissue, or bone COLLAGEN. It is used as a protein food adjuvant, plasma substitute, hemostatic, suspending agent in pharmaceutical preparations, and in the manufacturing of capsules and suppositories.

Gelatinases [M0027289]
A class of enzymes that catalyzes the degradation of gelatin by acting on the peptide bonds. EC 3.4.24.-.

Gelofusine [M0475082]

Gelsolin [M0027489]
A 90-kDa protein produced by macrophages that severs ACTIN filaments and forms a cap on the newly exposed filament end. Gelsolin is activated by CALCIUM ions and participates in the assembly and disassembly of actin, thereby increasing the motility of some CELLS.

Gen-Baclofen [M0454550]

Gene Product, A [M0024981]

Gene Product, Q [M0024982]

Gene Products, env [M0024061]
Retroviral proteins, often glycosylated, coded by the envelope (env) gene. They are usually synthesized as protein precursors (POLYPROTEINS) and later cleaved into the final viral envelope glycoproteins by a viral protease.

Gene Products, gag [M0024055]
Proteins coded by the retroviral gag gene. The products are usually synthesized as protein precursors or POLYPROTEINS, which are then cleaved by viral proteases to yield the final products. Many of the final products are associated with the nucleoprotein core of the virion. gag is short for group-specific antigen.

Gene Products, nef [M0024067]
Products of the HIV nef gene (formerly 3'-orf gene). The products trans-suppress viral replication and function as negative regulators of transcription. nef stands for negative factor.

Gene Products, pol [M0024059]
Retroviral proteins coded by the pol gene. They are usually synthesized as a protein precursor (POLYPROTEINS) and later cleaved into final products that include reverse transcriptase, endonuclease/integrase, and viral protease. Sometimes they are synthesized as a gag-pol fusion protein (FUSION PROTEINS, GAG-POL). pol is short for polymerase, the enzyme class of reverse transcriptase.

Gene Products, Protein [M0333263]

Gene Products, rev [M0024072]
Trans-acting nuclear proteins whose functional expression are required for HIV viral replication. Specifically, the rev gene products are required for processing and translation of the HIV gag and env mRNAs, and thus rev regulates the expression of the viral structural proteins. rev can also regulate viral regulatory proteins. A cis-acting antirepression sequence (CAR) in env, also known as the rev-responsive element (RRE), is responsive to the rev gene product. rev is short for regulator of virion.

Gene Products, rex [M0025040]
Post-transcriptional regulatory proteins required for the accumulation of mRNAs that encode the gag and env gene products in HUMAN T-LYMPHOTROPIC VIRUS 1 and HUMAN T-LYMPHOTROPIC VIRUS 2. The rex (regulator x; x is undefined) products act by binding to elements in the LTR.

Gene Products, tat [M0024076]
Trans-acting transcription factors. Nuclear proteins whose expression is required for HIV viral replication. The tat protein stimulates HIV-LTR-driven RNA synthesis for both viral regulatory and viral structural proteins. tat stands for trans-activation of transcription.

Gene Products, tax [M0025005]
Transcriptional trans-acting proteins of the promoter elements found in the long terminal repeats (LTR) of HUMAN T-LYMPHOTROPIC VIRUS 1 and HUMAN T-LYMPHOTROPIC VIRUS 2. The tax (trans-activator x; x is undefined) proteins act by binding to enhancer elements in the LTR.

Gene Products, vif [M0024983]
A 23-kDa regulatory protein important for virion infectivity in HIV. The protein is found in the cytoplasm of HIV-infected cells and is not absolutely required for virion formation.

Gene Products, vpr [M0024969]
Trans-acting proteins which accelerate virus replication in HIV. The vpr proteins act in trans to increase the levels of HIV specified proteins. vpr is short for viral protein R, where R is undefined.

Gene Products, vpu [M0024973]
Non-glycosylated, membrane-associated, 16 kDa proteins which are expressed in large amounts in cells infected with HIV-1. The proteins are required for efficient virion maturation and release. They are not present in HIV-2 nor in SIMIAN IMMUNODEFICIENCY VIRUS. vpu is short for viral protein U, with U undefined.

General Transcription Initiation Complex Proteins [M0407610]

Genotropin [M0028844]

Geranylgeranyl-Diphosphate Geranylgeranyltransferase [M0189396]
An enzyme that catalyzes the condensation of two molecules of GERANYLGERANYL DIPHOSPHATE to give prephytoene diphosphate. The prephytoene diphosphate molecule is a precursor for CAROTENOIDS and other tetraterpenes.

Geranyltranstransferase [M0074380]
An enzyme involved in the MEVALONATE pathway, it catalyses the synthesis of FARNESYL DIPHOSPHATE from ISOPENTENYL DIPHOSPHATE and dimethylallyl diphosphate.

Geref [M0372558]

GFRA1 Receptor [M0479207]

GFRA2 Receptor [M0479208]

GFRA3 Receptor [M0479209]

GFRA4 Receptor [M0479210]

GinI Endonuclease [M0023449]

Glia Maturation Factor [M0328190]
A factor identified in the brain that influences the growth and differentiation of NEURONS and NEUROGLIA. Glia maturation factor beta is the 17-kDa polypeptide product of the GMFB gene and is the principal component of GLIA MATURATION FACTOR.

Glia Maturation Factor beta [M0328663]

Gliadin [M0009263]
Simple protein, one of the prolamines, derived from the gluten of wheat, rye, etc. May be separated into 4 discrete electrophoretic fractions. It is the toxic factor associated with celiac disease.

Glial Cell Line-Derived Neurotrophic Factor [M0233028]
The founding member of the glial cell line-derived neurotrophic factor family. It was originally characterized as a NERVE GROWTH FACTOR promoting the survival of MIDBRAIN dopaminergic NEURONS, and it has been studied as a potential treatment for PARKINSON DISEASE.

Glial Cell Line-Derived Neurotrophic Factor Receptors [M0166928]
A family of GLYCOSYLPHOSPHATIDYLINOSITOL-anchored cell surface receptors that are specific for GLIAL CELL LINE-DERIVED NEUROTROPHIC FACTORS. They form a multi-component receptor complex with PROTO-ONCOGENE PROTEIN C-RET and regulate a variety of intracellular SIGNAL TRANSDUCTION PATHWAYS in conjunction with c-ret protein.

Glial Cell Line-Derived Neurotrophic Factors [M0479211]
A family of closely related nerve growth factors that promote NEURON survival. They bind to GDNF RECEPTORS and stimulate SIGNAL TRANSDUCTION through PROTO-ONCOGENE PROTEIN C-RET.

Glial Fibrillary Acidic Protein [M0009264]
An intermediate filament protein found only in glial cells or cells of glial origin. MW 51,000.

Glial Growth Factor [M0063177]

Glicentin [M0160184]
A 69-amino acid peptide derived from the N-terminal of PROGLUCAGON. It is mainly produced by the INTESTINAL L CELLS. Further processing of glicentin yield a 30-amino acid N-terminal peptide (glicentin-related polypeptide) and a 37-amino acid peptide OXYNTOMODULIN. Both glicentin and oxyntomodulin can reduce digestive secretions and delay gastric emptying.

Glioma-Derived Vascular Endothelial Cell Growth Factor [M0175398]

Globins [M0009288]
The protein constituents of hemoglobin. The term is used for proteins attached to iron-porphyrin molecules such as hemoglobin and MYOGLOBIN proteins.

Globulin-N [M0025521]

Globulins [M0009293]

GLQ-223 [M0373906]

Glu-Plasminogen [M0016990]

Glucagon [M0009314]
A 29-amino acid pancreatic peptide derived from proglucagon which is also the precursor of intestinal GLUCAGON-LIKE PEPTIDES. Glucagon is secreted by PANCREATIC ALPHA CELLS and plays an important role in regulation of BLOOD GLUCOSE concentration, ketone metabolism, and several other biochemical and physiological processes. (From Gilman et al., Goodman and Gilman's The Pharmacological Basis of Therapeutics, 9th ed, p1511)

Glucagon Precursors [M0484570]

Glucagon-Like Peptide 1 [M0160181]
A peptide of 36 or 37 amino acids that is derived from PROGLUCAGON and mainly produced by the INTESTINAL L CELLS. GLP-1(1-37 or 1-36) is further N-terminally truncated resulting in GLP-1(7-37) or GLP-1-(7-36) which can be amidated. These GLP-1 peptides are known to enhance glucose-dependent INSULIN release, suppress GLUCAGON release and gastric emptying, lower BLOOD GLUCOSE, and reduce food intake.

Glucagon-Like Peptide 2 [M0358087]
A 33-amino acid peptide derived from the C-terminal of PROGLUCAGON and mainly produced by the INTESTINAL L CELLS. It stimulates intestinal mucosal growth and decreased apoptosis of ENTEROCYTES. GLP-2 enhances gastrointestinal function and plays an important role in nutrient homeostasis.

Glucagon-Like Peptides [M0007481]
Peptides derived from proglucagon which is also the precursor of pancreatic GLUCAGON. Despite expression of proglucagon in multiple tissues, the major production site of glucagon-like peptides (GLPs) is the INTESTINAL L CELLS. GLPs include glucagon-like peptide 1, glucagon-like peptide 2, and the various truncated forms.

Glucan 1,3-beta-Glucosidase [M0071240]
An exocellulase with specificity for 1,3-beta-D-glucasidic linkages. It catalyzes hydrolysis of beta-D-glucose units from the non-reducing ends of 1,3-beta-D-glucans, releasing GLUCOSE.

Glucan 1,4-alpha-Glucosidase [M0008019]
An enzyme that catalyzes the hydrolysis of terminal 1,4-linked alpha-D-glucose residues successively from non-reducing ends of polysaccharide chains with the release of beta-glucose. It is also able to hydrolyze 1,6-alpha-glucosidic bonds when the next bond in sequence is 1,4.

Glucan 1,4-beta-Glucosidase [M0092059]
An exocellulase with specificity for the hydrolysis of 1,4-beta-glucosidic linkages of 1,4-beta-D-glucans resulting in successive removal of GLUCOSE units.

Glucan Endo-1,3-beta-D-Glucosidase [M0007387]
An endocellulase with specificity for the hydrolysis of 1,3-beta-D-glucosidic linkages in 1,3-beta-D-glucans including laminarin, paramylon, and pachyman.

Glucanase 447-G [M0006107]

Glucoamylase G1 [M0008020]

Glucoamylase G2 [M0008021]

Glucocorticoid-Induced TNFR-Related Protein [M0493171]
A member of the TNF receptor family that was initially identified as a DEXAMETHASONE-induced protein from a T-CELL line. It may play a role in regulating APOPTOSIS and modulating immune response by T-lymphocytes. Signaling by the activated receptor occurs through its association with TNF RECEPTOR-ASSOCIATED FACTORS.

Glucokinase [M0009328]
A group of enzymes that catalyzes the conversion of ATP and D-glucose to ADP and D-glucose 6-phosphate. They are found in invertebrates and microorganisms, and are highly specific for glucose. (Enzyme Nomenclature, 1992) EC 2.7.1.2.

Glucosamine 6-Phosphate N-Acetyltransferase [M0074423]
An enzyme that catalyses the reaction of D-glucosamine 6-phosphate with ACETYL-COA to form N-acetylglucosamine 6-phosphate.

Glucosaminidases [M0009338]

Glucose 1-Dehydrogenase [M0118232]
A glucose dehydrogenase that catalyzes the oxidation of beta-D-glucose to form D-glucono-1,5-lactone, using NAD as well as NADP as a coenzyme.

Glucose Dehydrogenases [M0009343]
D-Glucose:1-oxidoreductases. Catalyzes the oxidation of D-glucose to D-glucono-gamma-lactone and reduced acceptor. Any acceptor except molecular oxygen is permitted. Includes EC 1.1.1.47; EC 1.1.1.118; EC 1.1.1.119 and EC 1.1.99.10.

Glucose Oxidase [M0009344]
An enzyme of the oxidoreductase class that catalyzes the conversion of beta-D-glucose and oxygen to D-glucono-1,5-lactone and peroxide. It is a flavoprotein, highly specific for beta-D-glucose. The enzyme is produced by Penicillium notatum and other fungi and has antibacterial activity in the presence of glucose and oxygen. It is used to estimate glucose concentration in blood or urine samples through the formation of colored dyes by the hydrogen peroxide produced in the reaction. (From Enzyme Nomenclature, 1992) EC 1.1.3.4.

Glucose Transport Proteins, Facilitative [M0014037]
A family of monosaccharide transport proteins characterized by 12 membrane spanning helices. They facilitate passive diffusion of GLUCOSE across the CELL MEMBRANE.

Glucose Transport-Inducing Protein [M0014038]

Glucose Transporter Type 1 [M0201643]
A ubiquitously expressed glucose transporter that is important for constitutive, basal GLUCOSE transport. It is predominately expressed in ENDOTHELIAL CELLS and ERYTHROCYTES at the BLOOD-BRAIN BARRIER and is responsible for GLUCOSE entry into the BRAIN.

Glucose Transporter Type 2 [M0208875]
A glucose transport facilitator that is expressed primarily in PANCREATIC BETA CELLS; LIVER; and KIDNEYS. It may function as a GLUCOSE sensor to regulate INSULIN release and glucose HOMEOSTASIS.

Glucose Transporter Type 3 [M0191856]
A major glucose transporter found in NEURONS.

Glucose Transporter Type 4 [M0199158]
A glucose transport protein found in mature MUSCLE CELLS and ADIPOCYTES. It promotes transport of glucose from the BLOOD into target TISSUES. The inactive form of the protein is localized in CYTOPLASMIC VESICLES. In response to INSULIN, it is translocated to the PLASMA MEMBRANE where it facilitates glucose uptake.

Glucose Transporter Type 5 [M0206865]
A hexose transporter that mediates FRUCTOSE transport in SKELETAL MUSCLE and ADIPOCYTES and is responsible for luminal uptake of dietary fructose in the SMALL INTESTINE.

Glucose-1-Phosphate Adenylyltransferase [M0074442]
An ATP-dependent enzyme that catalyzes the addition of ADP to alpha-D-glucose 1-phosphate to form ADP-glucose and diphosphate. The reaction is the rate-limiting reaction in prokaryotic GLYCOGEN and plant STARCH biosynthesis.

Glucose-6-Phosphatase [M0009349]
An enzyme that catalyzes the conversion of D-glucose 6-phosphate and water to D-glucose and orthophosphate. EC 3.1.3.9.

Glucose-6-Phosphate Isomerase [M0009354]
An enzyme that catalyzes the reversible interconversion of glucose 6-phosphate and fructose 6-phosphate, and is a part of the glycolytic and gluconeogenic pathways. Deficiency of the enzyme, an autosomal recessive trait, results in liver glycogenesis and hemolytic anemia. EC 5.3.1.9.

Glucosephosphatase [M0009350]

Glucosephosphate Dehydrogenase [M0009352]

Glucosidases [M0009357]
Enzymes that hydrolyze O-glucosyl-compounds. (Enzyme Nomenclature, 1992) EC 3.2.1.-.

Glucosylceramidase [M0009360]
A glycosidase that hydrolyzes a glucosylceramide to yield free ceramide plus glucose. Deficiency of this enzyme leads to abnormally high concentrations of glucosylceramide in the brain in GAUCHER DISEASE. EC 3.2.1.45.

Glucosyltransferases [M0009362]
Enzymes that catalyze the transfer of glucose from a nucleoside diphosphate glucose to an acceptor molecule which is frequently another carbohydrate. EC 2.4.1.-.

Glucuronidase [M0009366]

Glucuronosyltransferase [M0022213]
A family of enzymes accepting a wide range of substrates, including phenols, alcohols, amines, and fatty acids. They function as drug-metabolizing enzymes that catalyze the conjugation of UDPglucuronic acid to a variety of endogenous and exogenous compounds. EC 2.4.1.17.

Glue Protein, Drosophila [M0009372]

Glue Proteins, Drosophila [M0009367]
Glycosylated proteins which are part of the salivary glue that Drosophila larvae secrete as a means of fixing themselves to an external substrate for the duration of the pre-pupal and pupal period. The proteins which consist of at least eight polypeptides that are expressed during the third larval instar.

Glutamate [M0028012]

Glutamate Carboxypeptidase II [M0155584]
A metallocarboxypeptidase that is predominantly expressed as a membrane-bound enzyme. It catalyzes the hydrolysis of an unsubstituted, C-terminal glutamyl residue, typically from PTEROYLPOLYGLUTAMIC ACIDS. It was formerly classified as EC 3.4.19.8.

Glutamate Decarboxylase [M0009373]
A pyridoxal-phosphate protein that catalyzes the alpha-decarboxylation of L-glutamic acid to form gamma-aminobutyric acid and carbon dioxide. The enzyme is found in bacteria and in invertebrate and vertebrate nervous systems. It is the rate-limiting enzyme in determining GAMMA-AMINOBUTYRIC ACID levels in normal nervous tissues. The brain enzyme also acts on L-cysteate, L-cysteine sulfinate, and L-aspartate. EC 4.1.1.15.

Glutamate Dehydrogenase [M0009374]
An enzyme that catalyzes the conversion of L-glutamate and water to 2-oxoglutarate and NH3 in the presence of NAD+. (From Enzyme Nomenclature, 1992) EC 1.4.1.2.

Glutamate Dehydrogenase (NADP+) [M0027280]
An enzyme that catalyzes the conversion of L-glutamate, H2O, and NADP+ to 2-oxoglutarate, NH3, and NADPH. (From Enzyme Nomenclature, 1992) EC 1.4.1.4.

Glutamate Formimidoyltransferase [M0074550]
A PYRIDOXAL PHOSPHATE-containing enzyme that catalyzes the transfer of a formyl group from L-GLUTAMATE to N-formimidoyl-L-glutamate and TETRAHYDROFOLATE. This enzyme may also catalyze formyl transfer from 5-formyltetrahydrofolate to L-GLUTAMATE. This enzyme was formerly categorized as EC 2.1.2.6.

Glutamate Plasma Membrane Transport Proteins [M0475618]
A family of plasma membrane neurotransmitter transporter proteins that couple the uptake of GLUTAMATE with the import of SODIUM ions and PROTONS and the export of POTASSIUM ions. In the CENTRAL NERVOUS SYSTEM they regulate neurotransmission through synaptic reuptake of the excitatory neurotransmitter glutamate. Outside the central nervous system they function as signal mediators and regulators of glutamate metabolism.

Glutamate Synthase [M0009375]
An enzyme that catalyzes the formation of 2 molecules of glutamate from glutamine plus alpha-ketoglutarate in the presence of NADPH. EC 1.4.1.13.

Glutamate Synthase (NADH) [M0296881]
A FLAVOPROTEIN enzyme for AMMONIA assimilation in BACTERIA, microorganisms and PLANTS. It catalyzes the oxidation of 2 molecules of L-GLUTAMATE to generate L-GLUTAMINE and 2-oxoglutarate in the presence of NAD+.

Glutamate Transporter [M0074576]

Glutamate-5-Semialdehyde Dehydrogenase [M0074563]
An NADP+ dependent enzyme that catalyzes the oxidation of L-glutamate 5-semialdehyde to L-glutamyl 5-phosphate. It plays a role in the urea cycle and metabolism of amino groups.

Glutamate-Ammonia Ligase [M0009384]
An enzyme that catalyzes the conversion of ATP, L-glutamate, and NH3 to ADP, orthophosphate, and L-glutamine. It also acts more slowly on 4-methylene-L-glutamate. (From Enzyme Nomenclature, 1992) EC 6.3.1.2.

Glutamate-Aspartate Transporter [M0074577]

Glutamate-Cysteine Ligase [M0008975]
One of the enzymes active in the gamma-glutamyl cycle. It catalyzes the synthesis of gamma-glutamylcysteine from glutamate and cysteine in the presence of ATP with the formation of ADP and orthophosphate. EC 6.3.2.2.

Glutamate-tRNA Ligase [M0009385]
An enzyme that activates glutamic acid with its specific transfer RNA. EC 6.1.1.17.

Glutamates [M0009376]
Salts and esters of glutamic acid.

Glutamic Acid [M0028010]
A non-essential amino acid naturally occurring in the L-form. Glutamic acid is the most common excitatory neurotransmitter in the CENTRAL NERVOUS SYSTEM.

Glutamic Acid, (D)-Isomer [M0331178]

Glutaminase [M0009380]

Glutamine [M0009383]
A non-essential amino acid present abundantly throughout the body and is involved in many metabolic processes. It is synthesized from GLUTAMIC ACID and AMMONIA. It is the principal carrier of NITROGEN in the body and is an important energy source for many cells.

Glutamine-Fructose-6-Phosphate Transaminase (Isomerizing) [M0009334]
An enzyme that catalyzes the synthesis of fructose-6-phosphate plus glutamine from glutamate plus glucosamine-6-phosphate. EC 2.6.1.16.

Glutaminic Acids [M0009378]

Glutamyl Aminopeptidase [M0072559]
A ZINC-dependent membrane-bound aminopeptidase that catalyzes the N-terminal peptide cleavage of GLUTAMATE (and to a lesser extent ASPARTATE). The enzyme appears to play a role in the catabolic pathway of the RENIN-ANGIOTENSIN SYSTEM.

Glutaryl-CoA Dehydrogenase [M0074614]
A flavoprotein enzyme that is responsible for the catabolism of LYSINE; HYDROXYLYSINE; and TRYPTOPHAN. It catalyzes the oxidation of GLUTARYL-CoA to crotonoyl-CoA using FAD as a cofactor. Glutaric aciduria type I is an inborn error of metabolism due to the deficiency of glutaryl-CoA dehydrogenase.

Glutathione [M0009388]
A tripeptide with many roles in cells. It conjugates to drugs to make them more soluble for excretion, is a cofactor for some enzymes, is involved in protein disulfide bond rearrangement and reduces peroxides.

Glutathione Disulfide [M0029384]
A GLUTATHIONE dimer formed by a disulfide bond between the cysteine sulfhydryl side chains during the course of being oxidized.

Glutathione Disulfide, Ion(1-) [M0329123]

Glutathione Lipoperoxidase [M0009392]

Glutathione Peroxidase [M0009390]
An enzyme catalyzing the oxidation of 2 moles of glutathione in the presence of hydrogen peroxide to yield oxidized glutathione and water. EC 1.11.1.9.

Glutathione Reductase [M0009393]
Catalyzes the oxidation of GLUTATHIONE to GLUTATHIONE DISULFIDE in the presence of NADP+. Deficiency in the enzyme is associated with HEMOLYTIC ANEMIA. Formerly listed as EC 1.6.4.2.

Glutathione S-Transferase 3 [M0009395]

Glutathione S-Transferase A [M0009396]

Glutathione S-Transferase B [M0009397]

Glutathione S-Transferase C [M0009398]

Glutathione S-Transferase P [M0009399]

Glutathione S-Transferase pi [M0274123]
A glutathione transferase that catalyzes the conjugation of electrophilic substrates to GLUTATHIONE. This enzyme has been shown to provide cellular protection against redox-mediated damage by FREE RADICALS.

Glutathione Synthase [M0009394]
One of the enzymes active in the gamma-glutamyl cycle. It catalyzes the synthesis of glutathione from gamma-glutamylcysteine and glycine in the presence of ATP with the formation of ADP and orthophosphate. EC 6.3.2.3.

Glutathione Transferase [M0009402]
A transferase that catalyzes the addition of aliphatic, aromatic, or heterocyclic FREE RADICALS as well as EPOXIDES and arene oxides to GLUTATHIONE. Addition takes place at the SULFUR. It also catalyzes the reduction of polyol nitrate by glutathione to polyol and nitrite.

Glutathione Transferase E [M0009400]

Glutathione Transferase mu [M0009401]

Glutathione Transferase P1-1 [M0484026]

Glutelins [M0009404]

Gluten [M0009405]
A protein substance of wheat which is intermixed with the starchy endosperm of the grain. It causes the carbon dioxide produced during dough fermentation to be retained by the dough in a manner which provides the porous and spongy structure of bread. (From Merck Index, 11th ed)

Glyceraldehyde 3-Phosphate Dehydrogenase (NADP+) [M0009411]
An NADP-dependent, non-phosphorylating aldehyde dehydrogenase that catalyzes the irreversible oxidation of GLYCERALDEHYDE 3-PHOSPHATE to 3-phosphoglycerate. It is found in the cytosol of a wide variety of organisms.

Glyceraldehyde-3-Phosphate Dehydrogenase (NADP+)(Phosphorylating) [M0009410]
A phosphorylating glyceraldehyde-3-phosphate dehydrogenase found in the CHLOROPLASTS of higher plants. This enzyme exists as an A2B2 heterotetramer and transfers hydrogen to NADP. It plays an important role in catalyzing the reductive step of the Calvin cycle.

Glyceraldehyde-3-Phosphate Dehydrogenase (Phosphorylating) [M0009412]
An NAD-dependent glyceraldehyde-3-phosphate dehydrogenase found in the cytosol of eucaryotes. It catalyses the dehydrogenation and phosphorylation of GLYCERALDEHYDE 3-PHOSPHATE to 3-phospho-D-glyceroyl phosphate, which is an important step in the GLYCOLYSIS pathway.

Glyceraldehyde-3-Phosphate Dehydrogenases [M0009409]
Enzymes that catalyze the dehydrogenation of GLYCERALDEHYDE 3-PHOSPHATE. Several types of glyceraldehyde-3-phosphate-dehydrogenase exist including phosphorylating and non-phosphorylating varieties and ones that transfer hydrogen to NADP and ones that transfer hydrogen to NAD.

Glycerol Kinase [M0009418]
An enzyme that catalyzes the formation of glycerol 3-phosphate from ATP and glycerol. Dihydroxyacetone and L-glyceraldehyde can also act as acceptors; UTP and, in the case of the yeast enzyme, ITP and GTP can act as donors. It provides a way for glycerol derived from fats or glycerides to enter the glycolytic pathway. EC 2.7.1.30.

Glycerol-3-Phosphate Dehydrogenase (NAD+) [M0107787]
An NAD-dependent enzyme that catalyzes the oxidation of sn-glycerol 3-phosphate to glycerone phosphate.

Glycerol-3-Phosphate O-Acyltransferase [M0009419]
An enzyme that transfers acyl groups from acyl-CoA to glycerol-3-phosphate to form monoglyceride phosphates. It acts only with CoA derivatives of fatty acids of chain length above C-10. Also forms diglyceride phosphates. EC 2.3.1.15.

Glycerolphosphate Dehydrogenase [M0009420]

Glycerophosphoinositol Inositolphosphodiesterase [M0459696]
A phosphoric diester hydrolase with specificity for the cleavage of GLYCEROL from 1-(sn-glycero-3-phospho)-1D-myo-inositol. It also has specificity for hydrolysis of the cyclic phosphate bond in inositol 1,2-cyclic phosphate

Glycine [M0009451]
A non-essential amino acid. It is found primarily in gelatin and silk fibroin and used therapeutically as a nutrient. It is also a fast inhibitory neurotransmitter.

Glycine Carbonate (1:1), Monosodium Salt [M0331193]

Glycine Carbonate (2:1), Monolithium Salt [M0331188]

Glycine Carbonate (2:1), Monopotassium Salt [M0331187]

Glycine Carbonate (2:1), Monosodium Salt [M0331186]

Glycine Chenodeoxycholate [M0009453]

Glycine Decarboxylase Complex [M0465423]
A enzyme complex that catalyzes the oxidative DECARBOXYLATION and DEAMINATION of GLYCINE into CARBON DIOXIDE; AMMONIA; NADH; and N5N10-methylenetetrahydrofolate. It is composed of four different component protein components referred to as H, P, L, and T.

Glycine Decarboxylase Complex H-Protein [M0089783]
A LIPOIC ACID-containing protein that plays the pivotal role in the transfer of methylamine groups and reducing equivalents between the three enzymatic components of the glycine decarboxylase complex.

Glycine Dehydrogenase [M0074673]
An oxidoreductase that catalyzes the oxidative DEAMINATION of GLYCINE to GLYOXYLATE and AMMONIA in the presence of NAD. In BACTERIA lacking transaminating pathways the enzyme can act in the reverse direction to synthesize glycine from glyoxylate and ammonia and NADH.

Glycine Dehydrogenase (Decarboxylating) [M0177687]
A PYRIDOXAL PHOSPHATE dependent enzyme that catalyzes the decarboxylation of GLYCINE with the transfer of an aminomethyl group to the LIPOIC ACID moiety of the GLYCINE DECARBOXYLASE COMPLEX H-PROTEIN. Defects in P-protein are the cause of non-ketotic hyperglycinemia. It is one of four subunits of the glycine decarboxylase complex.

Glycine Hydrochloride [M0331190]

Glycine Hydrochloride (2:1) [M0331410]

Glycine Hydroxymethyltransferase [M0019677]
A pyridoxal phosphate enzyme that catalyzes the reaction of glycine and 5,10-methylene-tetrahydrofolate to form serine. It also catalyzes the reaction of glycine with acetaldehyde to form L-threonine. EC 2.1.2.1.

Glycine N-Methyltransferase [M0074681]
An enzyme that catalyzes the METHYLATION of GLYCINE using S-ADENOSYLMETHIONINE to form SARCOSINE with the concomitant production of S-ADENOSYLHOMOCYSTEINE.

Glycine Phosphate [M0331411]

Glycine Phosphate (1:1) [M0331194]

Glycine Plasma Membrane Transport Proteins [M0475615]
A family of sodium chloride-dependent neurotransmitter symporters that transport the amino acid GLYCINE. They differ from GLYCINE RECEPTORS, which signal cellular responses to GLYCINE. They are located primarily on the PLASMA MEMBRANE of NEURONS; GLIAL CELLS; EPITHELIAL CELLS; and RED BLOOD CELLS where they remove inhibitory neurotransmitter glycine from the EXTRACELLULAR SPACE. Glycine plasma membrane transport proteins are different than

Glycine Sulfate (3:1) [M0331189]

Glycine Transaminase [M0074672]
A PYRIDOXAL PHOSPHATE containing enzyme that catalyzes the transfer of amino group of GLYCINE onto 2-OXOGLUTARATE to generate GLYOXYLATE and L-GLUTAMATE.

Glycine Transporter 1 [M0384074]

Glycine Transporter 2 [M0384075]

Glycine, Calcium Salt [M0331184]

Glycine, Calcium Salt (2:1) [M0331185]

Glycine, Cobalt Salt [M0331181]

Glycine, Copper Salt [M0331183]

Glycine, Monoammonium Salt [M0331182]

Glycine, Monopotasssium Salt [M0331180]

Glycine, Monosodium Salt [M0331191]

Glycine, Sodium Hydrogen Carbonate [M0331192]

Glycine-tRNA Ligase [M0009506]
An enzyme that activates glycine with its specific transfer RNA. EC 6.1.1.14.

Glycochenodeoxycholic Acid [M0009452]
A bile salt formed in the liver from chenodeoxycholate and glycine, usually as the sodium salt. It acts as a detergent to solubilize fats for absorption and is itself absorbed. It is a cholagogue and choleretic.

Glycogen Debranching Enzyme [M0009461]

Glycogen Debranching Enzyme System [M0009460]
1,4-alpha-D-Glucan-1,4-alpha-D-glucan 4-alpha-D-glucosyltransferase/dextrin 6 alpha-D-glucanohydrolase. An enzyme system having both 4-alpha-glucanotransferase (EC 2.4.1.25) and amylo-1,6-glucosidase (EC 3.2.1.33) activities. As a transferase it transfers a segment of a 1,4-alpha-D-glucan to a new 4-position in an acceptor, which may be glucose or another 1,4-alpha-D-glucan. As a glucosidase it catalyzes the endohydrolysis of 1,6-alpha-D-glucoside linkages at points of branching in chains of 1,4-linked alpha-D-glucose residues. Amylo-1,6-glucosidase activity is deficient in glycogen storage disease type III.

Glycogen Phosphorylase [M0332563]
An enzyme that catalyzes the degradation of GLYCOGEN in animals by releasing glucose-1-phosphate from the terminal alpha-1,4-glycosidic bond. This enzyme exists in two forms: an active phosphorylated form ( PHOSPHORYLASE A) and an inactive un-phosphorylated form (PHOSPHORYLASE B). Both a and b forms of phosphorylase exist as homodimers. In mammals, the major isozymes of glycogen phosphorylase are found in muscle, liver and brain tissue.

Glycogen Phosphorylase a, Brain Form [M0378533]

Glycogen Phosphorylase a, Liver Form [M0378535]

Glycogen Phosphorylase a, Muscle Form [M0378531]

Glycogen Phosphorylase b, Brain Form [M0378534]

Glycogen Phosphorylase b, Liver Form [M0378536]

Glycogen Phosphorylase b, Muscle Form [M0378532]

Glycogen Phosphorylase Kinase [M0016730]

Glycogen Phosphorylase Phosphatase [M0016732]

Glycogen Phosphorylase, Brain Form [M0372897]
An isoenzyme of GLYCOGEN PHOSPHORYLASE that catalyzes the degradation of GLYCOGEN in brain tissue.

Glycogen Phosphorylase, Liver Form [M0372890]
An isoenzyme of GLYCOGEN PHOSPHORYLASE that catalyzes the degradation of GLYCOGEN in liver tissue. Mutation of the gene coding this enzyme on chromosome 14 is the cause of GLYCOGEN STORAGE DISEASE TYPE VI.

Glycogen Phosphorylase, Muscle Form [M0332561]
An isoenzyme of GLYCOGEN PHOSPHORYLASE that catalyzes the degradation of GLYCOGEN in muscle. Mutation of the gene coding this enzyme is the cause of McArdle disease (GLYCOGEN STORAGE DISEASE TYPE V).

Glycogen Synthase [M0009463]
An enzyme that catalyzes the transfer of D-glucose from UDPglucose into 1,4-alpha-D-glucosyl chains. EC 2.4.1.11.

Glycogen Synthase I [M0009466]

Glycogen Synthase Kinase 3 [M0143054]
A glycogen synthase kinase that was originally described as a key enzyme involved in glycogen metabolism. It regulates a diverse array of functions such as CELL DIVISION, microtubule function and APOPTOSIS.

Glycogen Synthase Kinases [M0416370]
A class of protein-serine-threonine kinases that was originally found as one of the three types of kinases that phosphorylate GLYCOGEN SYNTHASE. Glycogen synthase kinases along with CA(2+)-CALMODULIN DEPENDENT PROTEIN KINASES and CYCLIC AMP-DEPENDENT PROTEIN KINASES regulate glycogen synthase activity.

Glycogen-Synthase-D Phosphatase [M0009467]
An enzyme that catalyzes the conversion of phosphorylated, inactive glycogen synthase D to active dephosphoglycogen synthase I. EC 3.1.3.42.

Glycolaldehyde Dehydrogenase [M0074978]
An enzyme that catalyzes the oxidation of GLYCOLALDEHYDE to GLYCOLATE, using NAD and NADP as COENZYMES.

Glycopeptidase A [M0444810]

Glycopeptidase F [M0444811]

Glycopeptides [M0009481]
Proteins which contain carbohydrate groups attached covalently to the polypeptide chain. The protein moiety is the predominant group with the carbohydrate making up only a small percentage of the total weight.

Glycophorin [M0009482]
The major sialoglycoprotein of the human erythrocyte membrane. It consists of at least two sialoglycopeptides and is composed of 60% carbohydrate including sialic acid and 40% protein. It is involved in a number of different biological activities including the binding of MN blood groups, influenza viruses, kidney bean phytohemagglutinin, and wheat germ agglutinin.

Glycophorin A [M0009483]

Glycophorin A(M) [M0009484]

Glycophorin B [M0009485]

Glycophorin C [M0009486]

Glycophorin E [M0009488]

Glycophorin HA [M0009487]

Glycoprotein gp68 [M0000779]

Glycoprotein Hormones, alpha Subunit [M0023540]
The alpha chain of pituitary glycoprotein hormones (THYROTROPIN; FOLLICLE STIMULATING HORMONE; LUTEINIZING HORMONE) and the placental CHORIONIC GONADOTROPIN. Within a species, the alpha subunits of these four hormones are identical; the distinct functional characteristics of these glycoprotein hormones are determined by the unique beta subunits. Both subunits, the non-covalently bound heterodimers, are required for full biologic activity.

Glycoprotein Sialyltransferase [M0019823]

Glycoproteins [M0009493]
Conjugated protein-carbohydrate compounds including mucins, mucoid, and amyloid glycoproteins.

Glycoside Hydrolases [M0009499]

Glycosylceramidase [M0016613]
The enzyme hydrolyzing glycosyl-N-acylsphingosine to a sugar and N-acylsphingosine. It also catalyzes the hydrolysis of phlorizin to phloretin and glucose. It is found in the intestinal brush border membrane often in conjunction with lactase. EC 3.2.1.62.

Glycosyltransferases [M0025432]
Enzymes that catalyze the transfer of glycosyl groups to an acceptor. Most often another carbohydrate molecule acts as an acceptor, but inorganic phosphate can also act as an acceptor, such as in the case of PHOSPHORYLASES. Some of the enzymes in this group also catalyze hydrolysis, which can be regarded as transfer of a glycosyl group from the donor to water. Subclasses include the HEXOSYLTRANSFERASES; PENTOSYLTRANSFERASES; SIALYLTRANSFERASES; and those transferring other glycosyl groups. EC 2.4.

Glycylglycine [M0009507]
The simplest of all peptides. It functions as a gamma-glutamyl acceptor.

Glycylglycine Hydrochloride [M0330216]

Glycylglycine Monohydrochloride [M0330215]

Glypican-1 [M0495513]

Glypican-2 [M0495514]

Glypican-3 [M0258023]

Glypican-4 [M0495515]

Glypican-5 [M0495516]

Glypicans [M0029408]
A family of GLYCOSYLPHOSPHATIDYLINOSITOL-anchored, cell-surface heparan sulfate proteoglycans that may play a role in CELL GROWTH PROCESSES and CELL DIFFERENTIATION by modulating ligand-receptor interactions.

GMP Reductase [M0075016]
An enzyme that catalyzes the reversible oxidation of inosine 5'-phosphate (IMP) to guanosine 5'-phosphate (GMP) in the presence of AMMONIA and NADP+. This enzyme was formerly classified as EC 1.6.6.8.

Goldswite [M0434514]

Gonabion [M0009544]

Gonadorelin Acetate [M0331413]

Gonadorelin Hydrochloride [M0331412]

Gonadostatin [M0016914]

Gonadotropin-Releasing Hormone [M0012446]
A decapeptide that stimulates the synthesis and secretion of both pituitary gonadotropins, LUTEINIZING HORMONE and FOLLICLE STIMULATING HORMONE. GnRH is produced by neurons in the septum PREOPTIC AREA of the HYPOTHALAMUS and released into the pituitary portal blood, leading to stimulation of GONADOTROPHS in the ANTERIOR PITUITARY GLAND.

Gonadotropins [M0009540]
Hormones that stimulate gonadal functions such as GAMETOGENESIS and sex steroid hormone production in the OVARY and the TESTIS. Major gonadotropins are glycoproteins produced primarily by the adenohypophysis (GONADOTROPINS, PITUITARY) and the placenta (CHORIONIC GONADOTROPIN). In some species, pituitary PROLACTIN and PLACENTAL LACTOGEN exert some luteotropic activities.

Gonadotropins, Equine [M0009547]
Gonadotropins secreted by the pituitary or the placenta in horses. This term generally refers to the gonadotropins found in the pregnant mare serum, a rich source of equine CHORIONIC GONADOTROPIN; LUTEINIZING HORMONE; and FOLLICLE STIMULATING HORMONE. Unlike that in humans, the equine LUTEINIZING HORMONE, BETA SUBUNIT is identical to the equine choronic gonadotropin, beta. Equine gonadotropins prepared from pregnant mare serum are used in reproductive studies.

Gonadotropins, Pituitary [M0009549]
Hormones secreted by the adenohypophysis (PITUITARY GLAND, ANTERIOR) that stimulate gonadal functions in both males and females. They include FOLLICLE STIMULATING HORMONE that stimulates germ cell maturation (OOGENESIS; SPERMATOGENESIS), and LUTEINIZING HORMONE that stimulates the production of sex steroids (ESTROGENS; PROGESTERONE; ANDROGENS).

Goosecoid Protein [M0195581]
Goosecoid protein is a homeodomain protein that was first identified in XENOPUS. It is found in the SPEMANN ORGANIZER of VERTEBRATES and plays an important role in neuronal CELL DIFFERENTIATION and ORGANOGENESIS.

Goserelin [M0026217]
A synthetic long-acting agonist of GONADOTROPIN-RELEASING HORMONE. Goserelin is used in treatments of malignant NEOPLASMS of the prostate, uterine fibromas, and metastatic breast cancer.

Goserelin Acetate [M0373293]

GoxI Endonuclease [M0023450]

gp120(v-fms) [M0024882]

Gramicidin [M0009601]
A group of peptide antibiotics from BACILLUS brevis. Gramicidin C or S is a cyclic, ten-amino acid polypeptide and gramicidins A, B, D are linear. Gramicidin is one of the two principal components of TYROTHRICIN which is used topically for gram-positive organisms. It is toxic to blood, liver, kidneys, meninges, and the olfactory apparatus.

Gramicidin A [M0009594]

Gramicidin A(1) [M0009595]

Gramicidin B [M0330232]

Gramicidin C [M0009596]

Gramicidin J [M0330231]

Gramicidin K [M0009598]

Gramicidin NF [M0330228]

Gramicidin P [M0009599]

Gramicidin S [M0009600]

Gramoderm [M0373096]

Granulin Matrix Proteins [M0022734]

Granulocyte Colony Stimulating Factor, Recombinant [M0028830]
Granulocyte colony stimulating factors prepared by recombinant DNA technology.

Granulocyte Colony-Stimulating Factor [M0024696]
A glycoprotein of MW 25 kDa containing internal disulfide bonds. It induces the survival, proliferation, and differentiation of neutrophilic granulocyte precursor cells and functionally activates mature blood neutrophils. Among the family of colony-stimulating factors, G-CSF is the most potent inducer of terminal differentiation to granulocytes and macrophages of leukemic myeloid cell lines.

Granulocyte Macrophage Colony-Stimulating Factors, Recombinant [M0028835]
Granulocyte-macrophage colony-stimulating factors prepared by recombinant DNA technology.

Granulocyte-Macrophage Colony-Stimulating Factor [M0024695]
An acidic glycoprotein of MW 23 kDa with internal disulfide bonds. The protein is produced in response to a number of inflammatory mediators by mesenchymal cells present in the hemopoietic environment and at peripheral sites of inflammation. GM-CSF is able to stimulate the production of neutrophilic granulocytes, macrophages, and mixed granulocyte-macrophage colonies from bone marrow cells and can stimulate the formation of eosinophil colonies from fetal liver progenitor cells. GM-CSF can also stimulate some functional activities in mature granulocytes and macrophages.

Granzyme A [M0456799]

Granzyme B [M0168804]

Granzyme C [M0153862]

Granzyme K [M0210456]

Granzyme M [M0352923]

Granzymes [M0496635]
A family of serine endopeptidases found in the SECRETORY GRANULES of CYTOTOXIC T-LYMPHOCYTES. When secreted into the intercellular space granzymes act to eliminate transformed and virus-infected host cells.

GRB10 Adaptor Protein [M0246084]
A binding partner for several RECEPTOR PROTEIN-TYROSINE KINASES, including INSULIN RECEPTOR and INSULIN-LIKE GROWTH FACTOR RECEPTOR. It contains a C-terminal SH2 DOMAIN and mediates various SIGNAL TRANSDUCTION pathways.

GRB2 Adaptor Protein [M0204531]
A signal transducing adaptor protein that links extracellular signals to the MAP KINASE SIGNALING SYSTEM. Grb2 associates with activated EPIDERMAL GROWTH FACTOR RECEPTOR and PLATELET-DERIVED GROWTH FACTOR RECEPTORS via its SH2 DOMAIN. It also binds to and translocates the SON OF SEVENLESS PROTEINS through its SH3 DOMAINS to activate PROTO-ONCOGENE PROTEIN P21(RAS).

GRB2 Adaptor Protein, Grb3-3 Isoform [M0204529]
Grb3-3 is a natural isoform of GRB2 PROTEIN with a deletion in the SH2 DOMAIN. It acts as a dominant negative protein over GRB2, suppressing proliferative signals. It has also been implicated in APOPTOSIS.

GRB7 Adaptor Protein [M0207321]
A SH2 DOMAIN-containing protein that mediates SIGNAL TRANSDUCTION pathways from multiple CELL SURFACE RECEPTORS, including the EPHB1 RECEPTOR. It interacts with FOCAL ADHESION KINASE and is involved in CELL MIGRATION.

Green Fluorescent Proteins [M0198398]
Protein analogs and derivatives of the Aequorea victoria green fluorescent protein that emit light (FLUORESCENCE) when excited with ULTRAVIOLET RAYS. They are used in REPORTER GENES in doing GENETIC TECHNIQUES. Numerous mutants have been made to emit other colors or be sensitive to pH.

Griseusin Polyketide Synthase [M0171386]

GroEL Protein [M0028193]
A chaperonin 60 heat-shock protein isolated from Escherichia coli.

GroES Protein [M0028192]
A chaperonin 10 heat-shock protein isolated from Escherichia coli.

Growth Factors [M0496065]

Growth Hormone [M0020156]
A polypeptide that is secreted by the adenohypophysis (PITUITARY GLAND, ANTERIOR). Growth hormone, also known as somatotropin, stimulates mitosis, cell differentiation and cell growth. Species-specific growth hormones have been synthesized.

Growth Hormone, Recombinant [M0028828]
Growth hormone (somatotropin) can be synthesized with methods of recombinant DNA technology. Since action of GH is highly species-specific, recombinant growth hormones of several species (including humans, cows, and pigs) have been developed. They have been used to stimulate growth.

Growth Hormone-Releasing Hormone [M0020158]
A peptide of 44 amino acids in most species that stimulates the release and synthesis of GROWTH HORMONE. GHRF (or GRF) is synthesized by neurons in the ARCUATE NUCLEUS of the HYPOTHALAMUS. After being released into the pituitary portal circulation, GHRF stimulates GH release by the SOMATOTROPHS in the PITUITARY GLAND.

Growth Suppressor Proteins [M0374859]

Growth-Associated Proteins, Neuronal [M0014657]

GTP Phosphohydrolases [M0328195]
Enzymes that hydrolyze GTP to GDP. EC 3.6.1.-.

GTP Pyrophosphokinase [M0001920]
An enzyme that catalyzes reversibly the transfer of a pyrophosphate group from ATP to the 3'-OH group of GDP or GTP with the formation of guanosine 3'-diphosphate 5'-diphosphate or guanosine 3'-diphosphate 5'-triphosphate and AMP. The enzyme, also called stringent factor, is located in the relA gene in stringent strains of bacteria. The above synthesis is induced by mRNA and uncharged tRNA which is bound to the aminoacyl-t-RNA binding site of the ribosome by a codon-specific association. EC 2.7.6.5.

GTP-Binding Protein alpha Subunit, G11 [M0362770]

GTP-Binding Protein alpha Subunit, G12 [M0368030]

GTP-Binding Protein alpha Subunit, G13 [M0267113]

GTP-Binding Protein alpha Subunit, Gi [M0028610]

GTP-Binding Protein alpha Subunit, Gi2 [M0212481]
A PERTUSSIS TOXIN-sensitive GTP-binding protein alpha subunit. It couples with a variety of CELL SURFACE RECEPTORS, has been implicated in INTERLEUKIN-12 production, and may play a role in INFLAMMATORY BOWEL DISEASES.

GTP-Binding Protein alpha Subunit, Go [M0444929]

GTP-Binding Protein alpha Subunit, Go1 [M0368936]

GTP-Binding Protein alpha Subunit, GoA [M0188758]

GTP-Binding Protein alpha Subunit, GoC [M0188759]

GTP-Binding Protein alpha Subunit, Gq [M0305052]

GTP-Binding Protein alpha Subunits [M0355363]
The GTPase-containing subunits of heterotrimeric GTP-binding proteins. When dissociated from the heterotrimeric complex these subunits interact with a variety of second messenger systems. Hydrolysis of GTP by the inherent GTPase activity of the subunit causes it to revert to its inactive (heterotrimeric) form. The GTP-Binding protein alpha subunits are grouped into families according to the type of action they have on second messenger systems.

GTP-Binding Protein alpha Subunits, G12-G13 [M0444933]
A ubiquitously expressed family of heterotrimeric GTP-binding protein alpha subunits that signal through interactions with a variety of second messengers as GTPASE-ACTIVATING PROTEINS; GUANINE NUCLEOTIDE EXCHANGE FACTORS; and HEAT SHOCK PROTEINS. The G12-G13 part of the name is also spelled G12/G13.

GTP-Binding Protein alpha Subunits, Gi-Go [M0444924]
A family of heterotrimeric GTP-binding protein alpha subunits that were originally identified by their ability to inhibit ADENYLATE CYCLASE. Members of this family can couple to beta and gamma G-protein subunits that activate POTASSIUM CHANNELS. The Gi-Go part of the name is also spelled Gi/Go.

GTP-Binding Protein alpha Subunits, Gq-G11 [M0443587]
A family of heterotrimeric GTP-binding protein alpha subunits that activate PHOSPHOLIPASE C dependent signaling pathways. The Gq-G11 part of the name is also spelled Gq/G11.

GTP-Binding Protein alpha Subunits, Gs [M0028609]
A family of heterotrimeric GTP-binding protein alpha subunits that activate ADENYLATE CYCLASE.

GTP-Binding Protein beta Subunits [M0355364]
Heterotrimeric GTP-binding protein subunits that tightly associate with GTP-BINDING PROTEIN GAMMA SUBUNITS. A dimer of beta and gamma subunits is formed when the GTP-BINDING PROTEIN ALPHA SUBUNIT dissociates from the GTP-binding protein heterotrimeric complex. The beta-gamma dimer can play an important role in signal transduction by interacting with a variety of second messengers.

GTP-Binding Protein gamma Subunits [M0355365]
Heterotrimeric GTP-binding protein subunits that tightly associate with GTP-BINDING PROTEIN BETA SUBUNITS. A dimer of beta and gamma subunits is formed when the GTP-BINDING PROTEIN ALPHA SUBUNIT dissociates from the GTP-binding protein heterotrimeric complex. The beta-gamma dimer can play an important role in signal transduction by interacting with a variety of second messengers.

GTP-Binding Protein Regulators [M0328196]
Proteins that regulate the signaling activity of GTP-BINDING PROTEINS. They are divided into three categories depending upon whether they stimulate GTPase activity (GTPASE-ACTIVATING PROTEINS), inhibit release of GDP; (GUANINE NUCLEOTIDE DISSOCIATION INHIBITORS); or exchange GTP for GDP; (GUANINE NUCLEOTIDE EXCHANGE FACTORS).

GTP-Binding Proteins [M0028608]
Regulatory proteins that act as molecular switches. They control a wide range of biological processes including: receptor signaling, intracellular signal transduction pathways, and protein synthesis. Their activity is regulated by factors that control their ability to bind to and hydrolyze GTP to GDP. EC 3.6.1.-.

GTPase-Activating Proteins [M0328198]
Proteins that activate the GTPase of specific GTP-BINDING PROTEINS.

GTPase-Deficient Dynamin [M0356790]
Dynamins that contain an alanine in position 44 instead of lysine. The amino acid substitution causes the protein to be GTPase-deficient and unable to function normally in the cell. GTPase-deficient dynamins are used experimentally to study dynamin function.

Guanidinoacetate N-Methyltransferase [M0075029]
This enzyme catalyzes the last step of CREATINE biosynthesis by catalyzing the METHYLATION of GUANIDINOACETATE to CREATINE.

Guanine Deaminase [M0009680]
An enzyme that catalyzes the deamination of guanine to form xanthine. EC 3.5.4.3.

Guanine Nucleotide Dissociation Inhibitors [M0328200]
Protein factors that inhibit the dissociation of GDP from GTP-BINDING PROTEINS.

Guanine Nucleotide Exchange Factors [M0328201]
Protein factors that promote the exchange of GTP for GDP bound to GTP-BINDING PROTEINS.

Guanine Nucleotide-Releasing Factor 2 [M0328202]
A 145-kDa guanine nucleotide exchange factor that is specific for rap1 and ras GTP-BINDING PROTEINS. It associates with SH3 domains of the crk family of signaling proteins.

Guanylate Cyclase [M0009695]
An enzyme that catalyzes the conversion of GTP to 3',5'-cyclic GMP and pyrophosphate. It also acts on ITP and dGTP. (From Enzyme Nomenclature, 1992) EC 4.6.1.2.

Guanylate Cyclase-Activating Protein 1 [M0481128]

Guanylate Cyclase-Activating Protein 2 [M0481127]

Guanylate Cyclase-Activating Protein 3 [M0481126]

Guanylate Cyclase-Activating Proteins [M0239796]
Neuronal calcium sensor proteins that regulate the activation of membrane-bound GUANYLATE CYCLASE. They are primarily expressed in the RETINA where they play an important role in PHOTOTRANSDUCTION.

Guanylate Kinase [M0075053]
Catalyzes the ATP-dependent PHOSPHORYLATION of GMP to generate GDP and ADP.

Guanylate Kinase 1 [M0075047]

Gumbaral [M0019324]

H(+)-K(+)-Exchanging ATPase [M0026566]
An enzyme isolated from the gastric mucosa that catalyzes the hydrolysis of ATP coupled with the exchange of hydrogen and potassium ions across the cell wall. This enzyme was formerly listed as EC 3.6.1.36.

H(+)-Transporting ATP Synthase, Acyl-Phosphate-Linked [M0330239]

H2-Oxidizing Hydrogenase [M0010724]

Haemaccel [M0373157]

Hageman-Factor Fragments [M0024401]

Halorhodopsins [M0092739]
Light driven chloride ion pumps that are ubiquitously found in halophilic archaea (HALOBACTERIALES).

Hanganutziu-Deicher Antibodies [M0465766]

HapII Endonuclease [M0028380]

Haptocorrin [M0021777]

Haptoglobins [M0009800]
Plasma glycoproteins that form a stable complex with hemoglobin to aid the recycling of heme iron. They are encoded in man by a gene on the short arm of chromosome 16.

Hb A1a-2 [M0010113]

Heat-Shock Protein 27 [M0009985]

Heat-Shock Protein Chlamydomonas [M0009989]

Heat-Shock Protein pp3 [M0479377]

Heat-Shock Proteins [M0009986]
Proteins which are synthesized in eukaryotic organisms and bacteria in response to hyperthermia and other environmental stresses. They increase thermal tolerance and perform functions essential to cell survival under these conditions.

Heat-Shock Proteins, Small [M0478453]
A family of low molecular weight heat-shock proteins that can serve as MOLECULAR CHAPERONES.

Heavy Meromyosin [M0024310]

Heavy Meromyosin Subfragment-1 [M0024311]

Heavy Meromyosin Subfragment-2 [M0024312]

Heavy Neurofilament Protein [M0025717]

Hedgehog Protein, Vertebrate [M0235927]

Hedgehog Proteins [M0496695]
A family of intercellular signaling proteins that play and important role in regulating the development of many TISSUES and organs. Their name derives from the observation of a hedgehog-like appearance in DROSOPHILA embryos with genetic mutations that block their action.

Helminth Proteins [M0024202]
Proteins found in any species of helminth.

Hematopoietic Cell Growth Factors [M0024907]
These growth factors comprise a family of hematopoietic regulators with biological specificities defined by their ability to support proliferation and differentiation of blood cells of different lineages. ERYTHROPOIETIN and the COLONY-STIMULATING FACTORS belong to this family. Some of these factors have been studied and used in the treatment of chemotherapy-induced neutropenia, myelodysplastic syndromes, and bone marrow failure syndromes.

Hematopoietic Stem Cell Stimulators [M0024908]

Hematopoietic Stem Cell-Activating Factors [M0024909]

Heme Oxygenase (Decyclizing) [M0010067]
A mixed function oxidase enzyme which during hemoglobin catabolism catalyzes the degradation of heme to ferrous iron, carbon monoxide and biliverdin in the presence of molecular oxygen and reduced NADPH. The enzyme is induced by metals, particularly cobalt. EC 1.14.99.3.

Heme Oxygenase-1 [M0275885]
A ubiquitous stress-responsive enzyme that catalyzes the oxidative cleavage of HEME to yield IRON; CARBON MONOXIDE; and BILIVERDIN.

Hemeproteins [M0010068]
Proteins that contain an iron-porphyrin, or heme, prosthetic group resembling that of hemoglobin. (From Lehninger, Principles of Biochemistry, 1982, p480)

Hemerythrin [M0010069]
A non-heme iron protein consisting of eight apparently identical subunits each containing 2 iron atoms. It binds one molecule of oxygen per pair of iron atoms and functions as a respiratory protein.

Hemocaprol [M0432618]

Hemocoagulase [M0333035]

Hemocyanin [M0010100]

Hemofil [M0372892]

Hemoglobin A [M0010111]
Normal adult human hemoglobin. The globin moiety consists of two alpha and two beta chains.

Hemoglobin A, Glycosylated [M0010114]
Minor hemoglobin components of human erythrocytes designated A1a, A1b, and A1c. Hemoglobin A1c is most important since its sugar moiety is glucose covalently bound to the terminal amino acid of the beta chain. Since normal glycohemoglobin concentrations exclude marked blood glucose fluctuations over the preceding three to four weeks, the concentration of glycosylated hemoglobin A is a more reliable index of the blood sugar average over a long period of time.

Hemoglobin A2 [M0010117]
An adult hemoglobin component normally present in hemolysates from human erythrocytes in concentrations of about 3%. The hemoglobin is composed of two alpha chains and two delta chains. The percentage of HbA2 varies in some hematologic disorders, but is about double in beta-thalassemia.

Hemoglobin C [M0010118]
A commonly occurring abnormal hemoglobin in which lysine replaces a glutamic acid residue at the sixth position of the beta chains. It results in reduced plasticity of erythrocytes.

Hemoglobin E [M0010120]
An abnormal hemoglobin that results from the substitution of lysine for glutamic acid at position 26 of the beta chain. It is most frequently observed in southeast Asian populations.

Hemoglobin H [M0010121]
An abnormal hemoglobin composed of four beta chains. It is caused by the reduced synthesis of the alpha chain. This abnormality results in ALPHA-THALASSEMIA.

Hemoglobin J [M0010122]
A group of abnormal hemoglobins with similar electrophoretic characteristics. They have faster electrophoretic mobility and different amino acid substitutions in either the alpha or beta chains than normal adult hemoglobin. Some of the variants produce hematologic abnormalities, others result in no clinical disorders.

Hemoglobin M [M0010123]
A group of abnormal hemoglobins in which amino acid substitutions take place in either the alpha or beta chains but near the heme iron. This results in facilitated oxidation of the hemoglobin to yield excess methemoglobin which leads to cyanosis.

Hemoglobin SS [M0010126]

Hemoglobin, Glycosylated [M0010112]

Hemoglobin, Glycosylated A1a-1 [M0010115]

Hemoglobin, Glycosylated A1b [M0010116]

Hemoglobin, Sickle [M0010127]
An abnormal hemoglobin resulting from the substitution of valine for glutamic acid at position 6 of the beta chain of the globin moiety. The heterozygous state results in sickle cell trait, the homozygous in sickle cell anemia.

Hemoglobins [M0010133]
The oxygen-carrying pigments of erythrocytes. They are found in all vertebrates and some invertebrates. The structure of the globin moiety differs between species.

Hemoglobins, Abnormal [M0010134]
Hemoglobins characterized by structural alterations within the molecule. The alteration can be either absence, addition or substitution of one or more amino acids in the globin part of the molecule at selected positions in the polypeptide chains.

Hemolytic Complement [M0004916]

Hemopexin [M0010148]

Hemosiderin [M0010178]

Heparan Sulfate Proteoglycans [M0029407]
Ubiquitous macromolecules associated with the cell surface and extracellular matrix of a wide range of cells of vertebrate and invertebrate tissues. They are essential cofactors in cell-matrix adhesion processes, in cell-cell recognition systems, and in receptor-growth factor interactions. (From Cancer Metastasis Rev 1996; 15(2): 177-86; Hepatology 1996; 24(3): 524-32)

Heparin Cofactor II [M0024263]
A sulfated plasma protein with the MW of approximately 66kDa that resembles ANTITHROMBIN III. The protein is an inhibitor of thrombin in plasma and is activated by dermatan sulfate or heparin. It is a member of the serpin superfamily.

Heparin Lyase [M0029324]
An enzyme of the isomerase class that catalyzes the eliminative cleavage of polysaccharides containing 1,4-linked D-glucuronate or L-iduronate residues and 1,4-alpha-linked 2-sulfoamino-2-deoxy-6-sulfo-D-glucose residues to give oligosaccharides with terminal 4-deoxy-alpha-D-gluc-4-enuronosyl groups at their non-reducing ends. (From Enzyme Nomenclature, 1992) EC 4.2.2.7.

Heparin-Binding Growth Factor Receptor [M0134917]

Hepatic Asialoglycoprotein Receptor [M0085794]
Asialoglycoprotein receptor found in liver.

Hepatitis A Antibodies [M0090664]
Antibodies to the HEPATITIS A ANTIGENS including antibodies to envelope, core, and non-structural proteins.

Hepatitis Antibodies [M0010209]
Immunoglobulins raised by any form of viral hepatitis; some of these antibodies are used to diagnose the specific kind of hepatitis.

Hepatitis Virus (MHV) Glycoprotein E2 [M0022712]

Hepatocyte Growth Factor [M0026141]
Multifunctional growth factor which regulates both cell growth and cell motility. It exerts a strong mitogenic effect on hepatocytes and primary epithelial cells. Its receptor is PROTO-ONCOGENE PROTEINS C-MET.

Hepatocyte Nuclear Factor 1 [M0170063]
A transcription factor that regulates the expression of a large set of hepatic proteins including SERUM ALBUMIN; beta-fibrinogen; and ALPHA 1-ANTITRYPSIN. It is composed of hetero- or homo-dimers of HEPATOCYTE NUCLEAR FACTOR 1-ALPHA and HEPATOCYTE NUCLEAR FACTOR 1-BETA.

Hepatocyte Nuclear Factor 1-alpha [M0466508]
Hepatocyte nuclear factor 1-alpha is a transcription factor found in the LIVER; PANCREAS; and KIDNEY that regulates HOMEOSTASIS of GLUCOSE.

Hepatocyte Nuclear Factor 1-beta [M0187934]
A hepatocyte nuclear factor that is closely related to HEPATOCYTE NUCLEAR FACTOR 1-ALPHA but is only weakly expressed in the LIVER. Mutations in hepatocyte nuclear factor 1-beta are associated with renal CYSTS and MATURITY-ONSET DIABETES MELLITUS type 5.

Hepatocyte Nuclear Factor 3-alpha [M0182071]
A forkhead transcription factor that is an essential activator of GLUCAGON gene expression.

Hepatocyte Nuclear Factor 3-beta [M0185682]
A forkhead transcription factor that regulates expression of metabolic GENES and is involved in EMBRYONIC DEVELOPMENT. Mutations in HNF-3beta have been associated with PERSISTENT HYPERINSULINEMIA HYPOGLYCEMIA OF INFANCY.

Hepatocyte Nuclear Factor 3-gamma [M0185686]
A winged-helix transcription factor that regulates GENE expression in metabolic tissues. It plays a role in HOMEOSTASIS of GLUCOSE and controls expression of GLUT2 PROTEIN.

Hepatocyte Nuclear Factor 4 [M0184201]
A subfamily of nuclear receptors that regulate GENETIC TRANSCRIPTION of a diverse group of GENES involved in the synthesis of BLOOD COAGULATION FACTORS; and in GLUCOSE; CHOLESTEROL; and FATTY ACIDS metabolism.

Hepatocyte Nuclear Factor 4-alpha [M0480926]

Hepatocyte Nuclear Factor 4-beta [M0480993]

Hepatocyte Nuclear Factor 4-gamma [M0362150]

Hepatocyte Nuclear Factor 6 [M0265795]
A onecut transcription factor that regulates expression of GENES involved in EMBRYONIC DEVELOPMENT of the PANCREAS and LIVER.

Hepatocyte Nuclear Factor 6-Alpha [M0481008]

Hepatocyte Nuclear Factor 6-Beta [M0481011]

Hepatocyte Nuclear Factors [M0480908]
Hepatocyte nuclear factors are a family of evolutionarily conserved transcription factors that are preferentially expressed in HEPATOCYTES. They play important roles in liver-specific transcription and are critical for CELL DIFFERENTIATION and METABOLISM.

Heregulin [M0332444]

Hermes Antigen Family [M0024734]

Hermesetas Gold [M0434515]

Herpes Simplex Virus Protein Vmw65 [M0026419]
Trans-acting protein that combines with host factors to induce immediate early gene transcription in herpes simplex virus.

Heterochromatin [M0010289]
The portion of chromosome material that remains condensed and is transcriptionally inactive during INTERPHASE.

Heterogeneous-Nuclear Ribonucleoprotein D [M0405771]
A heterogeneous-nuclear ribonucleoprotein that has specificity for AU-rich elements found in the 3'-region of mRNA and may play a role in RNA stability. Several isoforms of hnRNP D protein have been found to occur due to alternative mRNA splicing (RNA SPLICING).

Heterogeneous-Nuclear Ribonucleoprotein Group A-B [M0405710]
A class of closely related heterogeneous-nuclear ribonucleoproteins of approximately 34-40 kDa in size. Although they are generally found in the nucleoplasm, they also shuttle between the nucleus and the cytoplasm. Members of this class have been found to have a role in mRNA transport, telomere biogenesis and RNA SPLICING.

Heterogeneous-Nuclear Ribonucleoprotein Group C [M0405713]
A group of closely related heterogeneous-nuclear ribonucleoproteins of approximately 41-43 kDa in size found in the cell nucleus. Members of this class have been implicated in a variety of processes including splicing, polyadenylation, and nuclear retention of RNA.

Heterogeneous-Nuclear Ribonucleoprotein Group F [M0405798]

Heterogeneous-Nuclear Ribonucleoprotein Group F-H [M0405796]
A group of closely-related heterogeneous-nuclear ribonucleoproteins that are involved in pre-mRNA splicing.

Heterogeneous-Nuclear Ribonucleoprotein Group H [M0405797]

Heterogeneous-Nuclear Ribonucleoprotein Group M [M0406101]
A group of closely-related 72-74-kDa heterogeneous-nuclear ribonucleoproteins that are involved in RNA SPLICING events.

Heterogeneous-Nuclear Ribonucleoprotein K [M0087108]
A heterogeneous-nuclear ribonucleoprotein found in the CELL NUCLEUS and the CYTOPLASM. Heterogeneous-nuclear ribonucleoprotein K has been implicated in the regulation of gene expression at nearly all levels: GENETIC TRANSCRIPTION; mRNA processing (RNA PROCESSING, POST-TRANSCRIPTIONAL), mRNA transport, mRNA stability, and translation (TRANSLATION, GENETIC). The hnRNP protein has a strong affinity for polypyrimidine-rich RNA and for single-stranded polypyrimidine-rich DNA. Multiple hnRNP K protein isoforms exist due to alternative splicing and display different nucleic-acid-binding properties.

Heterogeneous-Nuclear Ribonucleoprotein L [M0333161]
A heterogenous-nuclear ribonucleoprotein found associated with most nascent transcripts, most notably those of the landmark giant loops of amphibian lampbrush chromosomes.

Heterogeneous-Nuclear Ribonucleoprotein U [M0087114]
A heterogeneous-nuclear ribonucleoprotein found associated with the NUCLEAR MATRIX.

Heterogeneous-Nuclear Ribonucleoproteins [M0087120]
A family of ribonucleoproteins that were originally found as proteins bound to nascent RNA transcripts in the form of ribonucleoprotein particles. Although considered ribonucleoproteins they are primarily classified by their protein component. They are involved in a variety of processes such as packaging of RNA and RNA TRANSPORT within the nucleus. A subset of heterogeneous-nuclear ribonucleoproteins are involved in additional functions such as nucleocytoplasmic transport (ACTIVE TRANSPORT, CELL NUCLEUS) of RNA and mRNA stability in the CYTOPLASM.

Heterotrimeric GTP-Binding Proteins [M0328203]
GTP-BINDING PROTEINS that contain three non-identical subunits. They are found associated with members of the seven transmembrane domain superfamily of G-PROTEIN-COUPLED RECEPTORS. Upon activation the GTP-BINDING PROTEIN ALPHA SUBUNIT of the complex dissociates leaving a dimer of a GTP-BINDING PROTEIN BETA SUBUNIT bound to a GTP-BINDING PROTEIN GAMMA SUBUNIT.

Hexalense [M0432619]

Hexokinase [M0010326]
An enzyme that catalyzes the conversion of ATP and a D-hexose to ADP and a D-hexose 6-phosphate. D-Glucose, D-mannose, D-fructose, sorbitol, and D-glucosamine can act as acceptors; ITP and dATP can act as donors. The liver isoenzyme has sometimes been called glucokinase. (From Enzyme Nomenclature, 1992) EC 2.7.1.1.

Hexokinase A [M0010327]

Hexokinase II [M0010328]

Hexosaminidase A [M0002425]

Hexosaminidase A Activating Protein [M0063219]

Hexosaminidase B [M0002424]

Hexosaminidases [M0010333]
Enzymes that catalyze the hydrolysis of N-acylhexosamine residues in N-acylhexosamides. Hexosaminidases also act on GLUCOSIDES; GALACTOSIDES; and several OLIGOSACCHARIDES.

Hexose Transport Proteins [M0014039]

Hexosyltransferases [M0010339]
Enzymes that catalyze the transfer of hexose groups. EC 2.4.1.-.

Heymann Nephritis Antigenic Complex [M0112829]
A complex of antigenic proteins obtained from the brush border of kidney tubules. It contains two principal components LDL-RECEPTOR RELATED PROTEIN 2 and LDL-RECEPTOR RELATED PROTEIN-ASSOCIATED PROTEIN. The name of this complex is derived from researcher, Dr. Walter Heymann, who developed an experimental model of membranous glomerulonephritis (GLOMERULONEPHRITIS) by injecting this antigenic complex into rats to induce an autoimmune response.

HHR6 Protein [M0257586]

High Mobility Group Proteins [M0010347]
A family of low-molecular weight, non-histone proteins found in chromatin.

High-Density Lipoprotein, Pre-beta1 [M0209807]

High-Density Lipoproteins, Pre-beta [M0209809]
A highly dense subclass of the high-density lipoproteins, with particle sizes below 7 nm. They are also known as nascent HDL, composed of a few APOLIPOPROTEIN A-I molecules which are complexed with PHOSPHOLIPIDS. The lipid-poor pre-beta-HDL particles serve as progenitors of HDL3 and then HDL2 after absorption of free cholesterol from cell membranes, cholesterol esterification, and acquisition of apolipoproteins A-II, Cs, and E. Pre-beta-HDL initiate the reverse cholesterol transport process from cells to liver.

Hiperlex [M0482931]

Hippocalcin [M0210201]
A neuronal calcium-sensor protein that was initially found in the NEURONS of the HIPPOCAMPUS. It interacts with NEURONAL APOPTOSIS-INHIBITORY PROTEIN.

Hirudin [M0010382]
A 65-residue polypeptide from LEECHES.

Hirudins [M0465835]
Single-chain polypeptides of about 65 amino acids (7 kDa) from LEECHES that have a neutral hydrophobic N terminus, an acidic hydrophilic C terminus, and a compact, hydrophobic core region. Recombinant hirudins lack tyr-63 sulfation so are referred to as 'desulfato-hirudins'. They form a stable non-covalent complex with ALPHA-THROMBIN, thereby abolishing its ability to cleave FIBRINOGEN.

Histamine Binding Sites [M0018599]

Histamine N-Methyltransferase [M0010398]
An enzyme that catalyzes the transfer of a methyl group from S-adenosylmethionine to histamine, forming N-methylhistamine, the major metabolite of histamine in man. EC 2.1.1.8.

Histidine [M0010400]
An essential amino acid that is required for the production of HISTAMINE.

Histidine Ammonia-Lyase [M0010399]
An enzyme that catalyzes the first step of histidine catabolism, forming UROCANIC ACID and AMMONIA from HISTIDINE. Deficiency of this enzyme is associated with elevated levels of serum histidine and is called histidinemia (AMINO ACID METABOLISM, INBORN ERRORS).

Histidine Decarboxylase [M0010401]
An enzyme that catalyzes the decarboxylation of histidine to histamine and carbon dioxide. It requires pyridoxal phosphate in animal tissues, but not in microorganisms. EC 4.1.1.22.

Histidine-tRNA Ligase [M0010404]
An enzyme that activates histidine with its specific transfer RNA. EC 6.1.1.21.

Histidinol-Phosphatase [M0010403]
An enzyme that catalyzes the hydrolysis of histidinol-phosphate to histidinol. One of the regulatory enzymes in histidine biosynthesis. EC 3.1.3.15.

Histocompatibility Antigens Class I [M0023721]
Large transmembrane, polymorphic glycoproteins noncovalently associated with nonpolymorphic beta 2-microglobulin. In humans, three structural genes on chromosome 6 code for the HLA-A; HLA-B and HLA-C antigens. In mice, three genes named K, D, and L on chromosome 17 code for the H-2 antigens. Class I antigens are found on most nucleated cells and are generally detected by their reactivity with alloantisera. These antigens are recognized during graft rejection and restrict cell-mediated lysis of virus-infected cells. They are primarily associated with rheumatologic diseases and certain malignant disorders.

Histocompatibility Antigens Class II [M0001420]
Large, transmembrane, non-covalently linked glycoproteins (alpha and beta). Both chains can be polymorphic although there is more structural variation in the beta chains. The class II antigens in humans are called HLA-D ANTIGENS and are coded by a gene on chromosome 6. In mice, two genes named IA and IE on chromosome 17 code for the H-2 antigens. The antigens are found on B-lymphocytes, macrophages, epidermal cells, and sperm and are thought to mediate the competence of and cellular cooperation in the immune response. The term IA antigens used to refer only to the proteins encoded by the IA genes in the mouse, but is now used as a generic term for any class II histocompatibility antigen.

Histone Acetyltransferases [M0458588]
Enzymes that catalyze acyl group transfer from ACETYL-CoA to HISTONES forming CoA and acetyl-histones.

Histone Deacetylases [M0010420]
Deacetylases that remove N-acetyl groups from amino side chains of the amino acids of HISTONES. Some of these belong to the SIRTUINS protein family.

Histone H1 [M0010422]

Histone H1(s) [M0010423]

Histone H2a [M0010424]

Histone H2b [M0010430]

Histone H3 [M0010425]

Histone H3.3 [M0010431]

Histone H4 [M0010426]

Histone H5 [M0010427]

Histone H7 [M0010428]

Histone-Lysine N-Methyltransferase [M0017870]
An enzyme that catalyzes the methylation of the epsilon-amino group of lysine residues in proteins to yield epsilon mono-, di-, and trimethyllysine. EC 2.1.1.43.

Histones [M0010429]
Small chromosomal proteins (approx 12-20 kD) possessing an open, unfolded structure and attached to the DNA in cell nuclei by ionic linkages. Classification into the various types (designated histone I, histone II, etc.) is based on the relative amounts of arginine and lysine in each.

HIV Antigens [M0023851]
Antigens associated with specific proteins of the human adult T-cell immunodeficiency virus (HIV); also called HTLV-III-associated and lymphadenopathy-associated virus (LAV) antigens.

HIV Core Protein p24 [M0025378]
A major core protein of the human immunodeficiency virus encoded by the HIV gag gene. HIV-seropositive individuals mount a significant immune response to p24 and thus detection of antibodies to p24 is one basis for determining HIV infection by ELISA and Western blot assays. The protein is also being investigated as a potential HIV immunogen in vaccines.

HIV Envelope Protein gp120 [M0024082]
External envelope protein of the human immunodeficiency virus which is encoded by the HIV env gene. It has a molecular weight of 120 kDa and contains numerous glycosylation sites. Gp120 binds to cells expressing CD4 cell-surface antigens, most notably T4-lymphocytes and monocytes/macrophages. Gp120 has been shown to interfere with the normal function of CD4 and is at least partly responsible for the cytopathic effect of HIV.

HIV Envelope Protein gp160 [M0028736]
An envelope protein of the human immunodeficiency virus that is encoded by the HIV env gene. It has a molecular weight of 160,000 kDa and contains numerous glycosylation sites. It serves as a precursor for both the HIV ENVELOPE PROTEIN GP120 and the HIV ENVELOPE PROTEIN GP41.

HIV Envelope Protein gp41 [M0024085]
Transmembrane envelope protein of the HUMAN IMMUNODEFICIENCY VIRUS which is encoded by the HIV env gene. It has a molecular weight of 41,000 and is glycosylated. The N-terminal part of gp41 is thought to be involved in CELL FUSION with the CD4 ANTIGENS of T4 LYMPHOCYTES, leading to syncytial formation. Gp41 is one of the most common HIV antigens detected by IMMUNOBLOTTING.

HIV Protease [M0024965]
Enzyme of the human immunodeficiency virus that is required for post-translational cleavage of gag and gag-pol precursor polyproteins into functional products needed for viral assembly. HIV protease is an aspartic protease encoded by the amino terminus of the pol gene. EC 3.4.23.-

HIV rev Gene Product [M0024073]

HIV tat Protein [M0024077]

HIV Transacting Transcription Protein [M0024078]

HIV vif Gene Product [M0024984]

HIV vpu Gene Product [M0024974]

HIV-1 Envelope Protein gp120 [M0024084]

HIV-1 Envelope Protein gp160 [M0028738]

HIV-1 Integrase [M0028902]

HIV-1 Protease [M0024966]

HIV-1 Reverse Transcriptase [M0028910]
HIV-1 enzyme responsible for the synthesis of DNA from genomic RNA of the virus. It exists as a heterodimer of a 66 kDa (p66) subunit and a 51 kDa (p51) subunit. It is encoded by the pol gene of HIV-1. EC 2.7.7.-.

HIV-1 Reverse Transcriptase p51 [M0028911]

HIV-1 Reverse Transcriptase p66 [M0028912]

HIV-1 vif Gene Products [M0024985]

HIV-2 Envelope Protein gp120 [M0024083]

HIV-2 Envelope Protein gp160 [M0028737]

HIV-2 Integrase [M0028903]

HIV-3'-orf Protein [M0024068]

HIV-F Protein [M0024069]

HLA Antigens [M0010472]
Antigens determined by leukocyte loci found on chromosome 6, the major histocompatibility loci in humans. They are polypeptides or glycoproteins found on most nucleated cells and platelets, determine tissue types for transplantation, and are associated with certain diseases.

HLA-A Antigens [M0023413]
Polymorphic class I human histocompatibility (HLA) surface antigens present on almost all nucleated cells. At least 20 antigens have been identified which are encoded by the A locus of multiple alleles on chromosome 6. They serve as targets for T-cell cytolytic responses and are involved with acceptance or rejection of tissue/organ grafts.

HLA-C Antigens [M0023415]
Class I human histocompatibility (HLA) antigens encoded by a small cluster of structural genes at the C locus on chromosome 6. They have significantly lower immunogenicity than the HLA-A and -B determinants and are therefore of minor importance in donor/recipient crossmatching. Their primary role is their high-risk association with certain disease manifestations (e.g., spondylarthritis, psoriasis, multiple myeloma).

HLA-D Antigens [M0010473]
Human immune-response or Class II antigens found mainly, but not exclusively, on B-lymphocytes and produced from genes of the HLA-D locus. They are extremely polymorphic families of glycopeptides, each consisting of two chains, alpha and beta. This group of antigens includes the -DR, -DQ and -DP designations, of which HLA-DR is most studied; some of these glycoproteins are associated with certain diseases, possibly of immune etiology.

HLA-DP Antigens [M0010474]
A group of the D-related HLA antigens (human) found to differ from the DR antigens in genetic locus and therefore inheritance. These antigens are polymorphic glycoproteins comprising alpha and beta chains and are found on lymphoid and other cells, often associated with certain diseases.

HLA-DQ Antigens [M0010475]
A group of the D-related HLA antigens found to differ from the DR antigens in genetic locus and therefore inheritance. These antigens are polymorphic glycoproteins comprising alpha and beta chains and are found on lymphoid and other cells, often associated with certain diseases.

HLA-DR5 Antigen [M0024206]
Human immune-response, D-related antigen encoded by the D-locus on chromosome 6 and found on lymphoid cells. It is associated with Kaposi sarcoma in AIDS and juvenile rheumatoid arthritis.

HMG Lepori [M0473965]

HMG Massone [M0473966]

HMGA Proteins [M0369233]
Proteins containing AT-HOOK MOTIFS that are rich in arginine and glycine residues. They bind to the minor grove of AT-rich regions of DNA.

HMGA1a Protein [M0375723]
An 11-kDa AT-hook motif-containing (AT-HOOK MOTIFS) protein that binds to the minor grove of AT-rich regions of DNA. It is the full-length product of the alternatively-spliced HMGA1 gene and may function as an architectural chromatin binding protein that is involved in transcriptional regulation.

HMGA1b Protein [M0212171]
An AT-hook motif-containing protein (AT-HOOK MOTIFS) that binds to the minor grove of AT-rich regions of DNA. It is a truncated form of HMGA1a protein that is produced by alternative-splicing of the HMGA1 gene. It may function as an architectural chromatin binding protein that is involved in transcriptional regulation.

HMGA1c Protein [M0375753]
An AT-hook-containing (AT-HOOK MOTIFS) nuclear protein that may be involved in retinoid-dependent transcriptional activity.

HMGA2 Protein [M0375725]
An AT-hook-containing (AT-HOOK MOTIFS) nuclear protein that is expressed predominantly in proliferating and undifferentiated mesenchymal cells.

HMGB Proteins [M0369232]
A family of sequence-related proteins similar to HMGB1 PROTEIN that contains specific HMG-BOX DOMAINS.

HMGB1 Protein [M0010348]
A 24-kDa HMGB protein that binds to and distorts the minor grove of DNA.

HMGB2 Protein [M0010351]
A 23-kDa HMG-box protein that binds to and distorts the minor grove of DNA.

HMGB3 Protein [M0370051]
An HMG-box domain (HMG-BOX DOMAINS) found highly expressed in embryonic tissue and in placenta.

HMGN Proteins [M0369230]
A family of HIGH MOBILITY GROUP PROTEINS that bind to NUCLEOSOMES.

HMGN1 Protein [M0010349]
An evolutionarily-conserved 10-kDa nuclear protein that binds NUCLEOSOMES and may be involved in the process of CHROMATIN unfolding.

HMGN2 Protein [M0010350]
An evolutionarily conserved 9-KDa nuclear protein that binds NUCLEOSOMES and may be involved in the process of CHROMATIN unfolding.

HN Glycoprotein, Sendai Virus [M0024091]

HN Protein [M0024092]
Glycoprotein from Sendai, para-influenza, Newcastle Disease, and other viruses that participates in binding the virus to cell-surface receptors. The HN protein possesses both hemagglutinin and neuraminidase activity.

hnRNP A2-B1 [M0194752]

HNRNP C Protein [M0406250]

hnRNP Complexes [M0411392]

hnRNP D Protein [M0408531]

hnRNP K Protein [M0406273]

hnRNP Particles [M0411393]

hnRNP Proteins [M0411391]

hnRNP U Protein [M0408537]

HOE-766 [M0369272]

Hoestil [M0447205]

Holliday Junction Resolvases [M0171985]
Enzymes that recognize CRUCIFORM DNA structures and introduce paired incisions that help to resolve the structure into two DNA helices.

Holo-Transcobalamin II [M0021778]

Holoenzymes [M0029742]
Catalytically active enzymes that are formed by the combination of an apoenzyme (APOENZYMES) and its appropriate cofactors and prosthetic groups.

Homeodomain Proteins [M0027627]
Proteins encoded by homeobox genes (GENES, HOMEOBOX) that exhibit structural similarity to certain prokaryotic and eukaryotic DNA-binding proteins. Homeodomain proteins are involved in the control of gene expression during morphogenesis and development (GENE EXPRESSION REGULATION, DEVELOPMENTAL).

Homing Receptors, T-Cell [M0024735]

Homoarginine [M0010513]

Homocysteine [M0010514]
A thiol-containing amino acid formed by a demethylation of METHIONINE.

Homocysteine S-Methyltransferase [M0076142]
An enzyme that catalyzes the demethylation of L-homocysteine to L-METHIONINE.

Homocystine [M0010515]

Homogentisate 1,2-Dioxygenase [M0076145]
A mononuclear Fe(II)-dependent oxygenase, this enzyme catalyzes the conversion of homogentisate to 4-maleylacetoacetate, the third step in the pathway for the catabolism of TYROSINE. Deficiency in the enzyme causes ALKAPTONURIA, an autosomal recessive disorder, characterized by homogentisic aciduria, OCHRONOSIS and ARTHRITIS. This enzyme was formerly characterized as EC 1.13.1.5 and EC 1.99.2.5.

Homoserine [M0010518]

Homoserine Dehydrogenase [M0010519]
An enzyme that catalyzes the reduction of aspartic beta-semialdehyde to homoserine, which is the branch point in biosynthesis of methionine, lysine, threonine and leucine from aspartic acid. EC 1.1.1.3.

Homoserine O-Succinyltransferase [M0076154]
The first enzyme in the METHIONINE biosynthetic pathway, this enzyme catalyzes the succinylation reaction of L-homoserine to O-succinyl-L-homoserine and COENZYME A using succinyl-CoA.

Hormone Receptors, Cell Surface [M0352710]

Hormone Receptors, Cytoplasmic [M0352724]

Hormone Receptors, Nuclear [M0352721]

Horseradish Peroxidase [M0010547]
An enzyme isolated from horseradish which is able to act as an antigen. It is frequently used as a histochemical tracer for light and electron microscopy. Its antigenicity has permitted its use as a combined antigen and marker in experimental immunology.

Horseradish Peroxidase II [M0010548]

Horseradish Peroxidase III [M0010549]

Host Cell Factor C1 [M0241725]
A cellular transcriptional coactivator that was originally identified by its requirement for the stable assembly IMMEDIATE-EARLY PROTEINS of the HERPES SIMPLEX VIRUS. It is a nuclear protein that is a transcriptional coactivator for a number of transcription factors including VP16 PROTEIN; GA-BINDING PROTEIN; EARLY GROWTH RESPONSE PROTEIN 2; and E2F4 TRANSCRIPTION FACTOR. It also interacts with and stabilizes HERPES SIMPLEX VIRUS PROTEIN VMW65 and helps regulate GENETIC TRANSCRIPTION of IMMEDIATE-EARLY GENES in HERPES SIMPLEX VIRUS.

Host Factor 1 Protein [M0089787]
An integration host factor that was originally identified as a bacterial protein required for the integration of bacteriophage Q beta (ALLOLEVIVIRUS). Its cellular function may be to regulate mRNA stability and processing in that it binds tightly to poly(A) RNA and interferes with ribosome binding.

hPD-ECGF [M0021453]

HsaI Endonuclease [M0023460]

HSC70 Heat-Shock Proteins [M0381630]
A constitutively expressed subfamily of the HSP70 heat-shock proteins. They preferentially bind and release hydrophobic peptides by an ATP-dependent process and are involved in post-translational PROTEIN TRANSLOCATION.

HSC73 Protein [M0253046]

HSP110 Heat-Shock Proteins [M0248618]
A group of eukaryotic high-molecular mass heat-shock proteins that represent a subfamily of HSP70 HEAT-SHOCK PROTEINS. Hsp110 proteins prevent protein aggregation and can maintain denatured proteins in folding-competent states.

HSP20 Heat-Shock Proteins [M0478448]
A subfamily of small heat-shock proteins that are closely related to ALPHA B-CRYSTALLIN. Hsp20 heat-shock proteins can undergo PHOSPHORYLATION by CYCLIC GMP-DEPENDENT PROTEIN KINASES.

HSP30 Heat-Shock Proteins [M0218707]
A subfamily of small heat-shock proteins found in a wide variety of organisms.

HSP40 Heat-Shock Proteins [M0138021]
A family of heat-shock proteins that contain a 70 amino-acid consensus sequence known as the J domain. The J domain of HSP40 heat shock proteins interacts with HSP70 HEAT-SHOCK PROTEINS. HSP40 heat-shock proteins play a role in regulating the ADENOSINE TRIPHOSPHATASES activity of HSP70 heat-shock proteins.

HSP47 Heat-Shock Proteins [M0216106]
Basic glycoprotein members of the SERPIN SUPERFAMILY that function as COLLAGEN-specific MOLECULAR CHAPERONES in the ENDOPLASMIC RETICULUM.

HSP70 Heat-Shock Proteins [M0028194]
A class of MOLECULAR CHAPERONES found in both prokaryotes and in several compartments of eukaryotic cells. These proteins can interact with polypeptides during a variety of assembly processes in such a way as to prevent the formation of nonfunctional structures.

HSP72 Heat-Shock Proteins [M0233684]
Stress-inducible members of the heat-shock proteins 70 family. HSP72 heat shock proteins function with other MOLECULAR CHAPERONES to mediate PROTEIN FOLDING and to stabilize pre-existent proteins against aggregation.

HSP90 Heat-Shock Proteins [M0028195]
A class of MOLECULAR CHAPERONES whose members act in the mechanism of SIGNAL TRANSDUCTION by STEROID RECEPTORS.

HTLV-I Post-Transcriptional Regulator Protein [M0025041]

HTLV-I Trans-Activator Protein [M0025003]

HTLV-II Post-Transcriptional Regulator Protein [M0025044]

HTLV-II Trans-Activator Protein [M0025010]

Hu Paraneoplastic Encephalomyelitis Antigens [M0193824]
A family of RNA-binding proteins that are homologues of ELAV protein, Drosophila. They were initially identified in humans as the targets of autoantibodies in patients with PARANEOPLASTIC ENCEPHALOMYELITIS. They are thought to regulate GENE EXPRESSION at the post-transcriptional level.

HuD Paraneoplastic Encephalomyelitis Antigen [M0193828]
HuD paraneoplastic encephalomyelitis antigen is an RNA-binding protein. It binds U-rich sequences in the 3' UNTRANSLATED REGIONS of mRNAs for PROTO-ONCOGENE PROTEINS C-FOS; CYCLIN-DEPENDENT KINASE INHIBITOR P21; and GAP-43 PROTEIN.

Human 4F2 Antigen [M0360036]

Human Chorionic Gonadotropin, alpha Subunit [M0397845]

Human Glandular Kallikrein 1 [M0333861]

Human Glandular Kallikrein 2 [M0115051]

Human Growth Hormone [M0028842]
A 191-amino acid polypeptide hormone secreted by the human adenohypophysis (PITUITARY GLAND, ANTERIOR), also known as GH or somatotropin. Synthetic growth hormone, termed somatropin, has replaced the natural form in therapeutic usage such as treatment of dwarfism in children with growth hormone deficiency.

Human Pancreatic Growth Hormone-Releasing Factor [M0482278]
Ectopic GHRH secreted by human pancreatic tumor.

Human PHI [M0016231]

Human Placental Lactogen [M0412452]

Humate-P [M0008150]

Humatrope [M0028843]

Humegon [M0013389]
FSH:LH = 1:1

Humulin [M0011414]

Humulin S [M0011415]

Hyaluronoglucosaminidase [M0010666]
An enzyme that catalyzes the random hydrolysis of 1,4-linkages between N-acetyl-beta-D-glucosamine and D-glucuronate residues in hyaluronate. (From Enzyme Nomenclature, 1992)

Hyatt-C [M0008148]

Hydopa [M0474249]

Hydro-Lyases [M0010685]
Enzymes that catalyze the breakage of a carbon-oxygen bond leading to unsaturated products via the removal of water. EC 4.2.1.

Hydrogenase [M0010725]
An enzyme found in bacteria. It catalyzes the reduction of ferredoxin and other substances in the presence of molecular hydrogen and is involved in the electron transport of bacterial photosynthesis. EC 1.18.99.1.

Hydrogenase 1 (Clostridium) [M0010726]

Hydrogensulfite Reductase [M0242049]
An enzyme found primarily in SULFUR-REDUCING BACTERIA where it plays an important role in the anaerobic carbon oxidation pathway.

Hydrolase S [M0439191]

Hydrolases [M0010728]
Any member of the class of enzymes that catalyze the cleavage of the substrate and the addition of water to the resulting molecules, e.g., ESTERASES, glycosidases (GLYCOSIDE HYDROLASES), lipases, NUCLEOTIDASES, peptidases (PEPTIDE HYDROLASES), and phosphatases (PHOSPHORIC MONOESTER HYDROLASES). EC 3.

Hydrotricine [M0373260]

Hydroxybutyrate Dehydrogenase [M0010749]

Hydroxylysine [M0010770]
A hydroxylated derivative of the amino acid LYSINE that is present in certain collagens.

Hydroxymethyl and Formyl Transferases [M0029514]
Enzymes that catalyze the transfer of hydroxymethyl or formyl groups. EC 2.1.2.

Hydroxymethylbilane Synthase [M0017332]
An enzyme that catalyzes the tetrapolymerization of the monopyrrole PORPHOBILINOGEN into the hydroxymethylbilane preuroporphyrinogen (UROPORPHYRINOGENS) in several discrete steps. It is the third enzyme in the 8-enzyme biosynthetic pathway of HEME. In humans, deficiency in this enzyme encoded by HMBS (or PBGD) gene results in a form of neurological porphyria (PORPHYRIA, ACUTE INTERMITTENT). This enzyme was formerly listed as EC 4.3.1.8

Hydroxymethylglutaryl CoA Reductases [M0010772]
Enzymes that catalyze the reversible reduction of alpha-carboxyl group of 3-HYDROXY-3-METHYLGLUTARYL-COENZYME A to yield MEVALONIC ACID.

Hydroxymethylglutaryl-CoA Reductases, NAD-Dependent [M0375836]
Specific hydroxymethylglutaryl CoA reductases that utilize the cofactor NAD. This class of enzymes performs a catabolic role in microorganisms such as Pseudomonas mevalonii where it oxidatively acetylates MEVALONIC ACID to form 3-HYDROXY-3-METHYLGLUTARYL-COENZYME A and NADH.

Hydroxymethylglutaryl-CoA Synthase [M0010773]
An enzyme that catalyzes the synthesis of hydroxymethylglutaryl-CoA from acetyl-CoA and acetoacetyl-CoA. This is a key enzyme in steroid biosynthesis. This enzyme was formerly listed as EC 4.1.3.5.

Hydroxymethylglutaryl-CoA-Reductases, NADP-dependent [M0090914]
Specific hydroxymethylglutaryl CoA reductases that utilize the cofactor NAD. In liver enzymes of this class are involved in cholesterol biosynthesis.

Hydroxyproline [M0010778]
A hydroxylated form of the imino acid proline. A deficiency in ASCORBIC ACID can result in impaired hydroxyproline formation.

Hydroxyprostaglandin Dehydrogenases [M0010781]
Catalyzes reversibly the oxidation of hydroxyl groups of prostaglandins.

Hydroxypyruvate Reductase [M0076294]
An enzyme that catalyzes the oxidation of D-glycerate to hydroxypyruvate in the presence of NADP.

Hydroxysteroid Dehydrogenases [M0010784]
Enzymes of the oxidoreductase class that catalyze the dehydrogenation of hydroxysteroids. (From Enzyme Nomenclature, 1992) EC 1.1.-.

Hydroxytryptophan [M0010788]

Hypertensin [M0372297]

Hypothalamic Hormones [M0010936]
Peptide hormones produced by NEURONS of various regions in the HYPOTHALAMUS. They are released into the pituitary portal circulation to stimulate or inhibit PITUITARY functions. VASOPRESSIN and OXYTOCIN, though produced in the hypothalamus, are not included here for they are transported down the AXONS to the POSTERIOR LOBE OF PITUITARY before being released into the portal circulation.

Hypothalamic Releasing Hormones [M0016915]

Hypothalamic Substance P [M0020675]

Hypoxanthine Phosphoribosyltransferase [M0010952]
An enzyme that catalyzes the conversion of 5-phosphoribosyl-1-pyrophosphate and hypoxanthine, guanine, or 6-mercaptopurine to the corresponding 5'-mononucleotides and pyrophosphate. The enzyme is important in purine biosynthesis as well as central nervous system functions. Complete lack of enzyme activity is associated with the LESCH-NYHAN SYNDROME, while partial deficiency results in overproduction of uric acid. EC 2.4.2.8.

Hypoxia-Inducible Factor 1 [M0216225]
A basic helix-loop-helix transcription factor that plays a role in APOPTOSIS. It is composed of two subunits: ARYL HYDROCARBON RECEPTOR NUCLEAR TRANSLOCATOR and HYPOXIA-INDUCIBLE FACTOR 1, ALPHA SUBUNIT.

Hypoxia-Inducible Factor 1, alpha Subunit [M0404124]
Hypoxia-inducible factor 1, alpha subunit is a basic helix-loop-helix transcription factor that is regulated by OXYGEN availability and is targeted for degradation by VHL TUMOR SUPPRESSOR PROTEIN.

I-kappa B Kinase [M0279189]
A protein serine-threonine kinase that catalyzes the PHOSPHORYLATION of I KAPPA B PROTEINS. This enzyme also activates the transcription factor NF-KAPPA B and is composed of alpha and beta catalytic subunits, which are protein kinases and gamma, a regulatory subunit.

I-kappa B Proteins [M0328543]
A family of inhibitory proteins which bind to the REL PROTO-ONCOGENE PROTEINS and modulate their activity. In the CYTOPLASM, I-kappa B proteins bind to the transcription factor NF-KAPPA B. Cell stimulation causes its dissociation and translocation of active NF-kappa B to the nucleus.

IA-887 [M0369473]

ICERIgamma [M0415516]

ICERIIgamma [M0415517]

ICI-118630 [M0373292]

Iduronate Sulfatase [M0010995]
An enzyme that specifically cleaves the ester sulfate of iduronic acid. Its deficiency has been demonstrated in Hunter's syndrome, which is characterized by an excess of dermatan sulfate and heparan sulfate. EC 3.1.6.13.

Iduronidase [M0010998]
An enzyme that hydrolyzes iduronosidic linkages in desulfated dermatan. Deficiency of this enzyme produces Hurler's syndrome. EC 3.2.1.76.

IFNAR2.1 Subunit, Interferon alpha-beta Receptor [M0495184]
A shortened cytoplasmic domain variant of the IFNAR2 chain.

IFNAR2.2 Subunit, Interferon alpha-beta Receptor [M0495186]
The full-length variant of the IFNAR2 chain.

Ig-EBP-1 [M0024956]

IgA1 [M0011001]

IgA2 [M0011002]

IgD1 [M0011006]

IgD2 [M0011007]

IgG(T) [M0011011]

IgG1 [M0011012]

IgG2 [M0011013]

IgG2A [M0011014]

IgG2B [M0011015]

IgG3 [M0011016]

IgG4 [M0011017]

IgM1 [M0011020]

IgM2 [M0011021]

IkappaB Kinase alpha [M0279186]

IkappaB Kinase beta [M0279183]

IkappaB Kinase epsilon [M0442052]

IkappaB Kinase gamma [M0279184]

Ikaros Transcription Factor [M0208676]
A transcription factor that plays a role as a key regulator of HEMATOPOIESIS. Aberrant Ikaros expression has been associated with LYMPHOBLASTIC LEUKEMIAS.

Iletin [M0011416]

Ilozyme [M0474887]

Ilube [M0447375]

Iminase [M0433989]

Imino Acids [M0011055]

Immediate-Early Proteins [M0027006]
Proteins that are coded by immediate-early genes, in the absence of de novo protein synthesis. The term was originally used exclusively for viral regulatory proteins that were synthesized just after viral integration into the host cell. It is also used to describe cellular proteins which are synthesized immediately after the resting cell is stimulated by extracellular signals.

Immunoconglutinins [M0091662]
Autoantibodies directed against newly-formed EPITOPES created as the COMPLEMENT cascade is activated and the proteins involved change their conformations.

Immunoglobulin A [M0011000]
Represents 15-20% of the human serum immunoglobulins, mostly as the 4-chain polymer in humans or dimer in other mammals. Secretory IgA (IMMUNOGLOBULIN A, SECRETORY) is the main immunoglobulin in secretions.

Immunoglobulin A, Secretory [M0011004]
The principle immunoglobulin in exocrine secretions such as milk, respiratory and intestinal mucin, saliva and tears. The complete molecule (around 400 kD) is composed of two four-chain units of IMMUNOGLOBULIN A, one SECRETORY COMPONENT and one J chain (IMMUNOGLOBULIN J-CHAINS).

Immunoglobulin alpha-Chains [M0011123]
The class of heavy chains found in IMMUNOGLOBULIN A. They have a molecular weight of approximately 58 kDa and contain about 470 amino acid residues arranged in four domains and an oligosaccharide component bound covalently to their Fc fragment constant region.

Immunoglobulin Constant Regions [M0011105]
The domains of the immunoglobulin molecules that are invariable in their amino acid sequence within any class or subclass of immunoglobulin. They confer biological as well as structural functions to immunoglobulins. One each on both the light chains and the heavy chains comprises the C-terminus half of the IMMUNOGLOBULIN FAB FRAGMENT and two or three of them make up the rest of the heavy chains (all of the IMMUNOGLOBULIN FC FRAGMENT)

Immunoglobulin D [M0011005]
An immunoglobulin which accounts for less than 1% of plasma immunoglobulin. It is found on the membrane of many circulating B LYMPHOCYTES.

Immunoglobulin delta-Chains [M0011124]
The class of heavy chains found in IMMUNOGLOBULIN D. They have a molecular weight of approximately 64 kDa and they contain about 500 amino acid residues arranged in four domains and an oligosaccharide component covalently bound to the Fc fragment constant region.

Immunoglobulin E [M0011008]
An immunoglobulin associated with MAST CELLS. Overexpression has been associated with allergic hypersensitivity (HYPERSENSITIVITY, IMMEDIATE).

Immunoglobulin epsilon-Chains [M0011125]
The class of heavy chains found in IMMUNOGLOBULIN E. They have a molecular weight of approximately 72 kDa and they contain about 550 amino acid residues arranged in five domains and about three times more carbohydrate than the heavy chains of IMMUNOGLOBULIN A; IMMUNOGLOBULIN D; and IMMUNOGLOBULIN G.

Immunoglobulin Fab Fragments [M0011126]
Univalent antigen-binding fragments composed of one entire IMMUNOGLOBULIN LIGHT CHAIN and the amino terminal end of one of the IMMUNOGLOBULIN HEAVY CHAINS from the hinge region, linked to each other by disulfide bonds. Fab contains the IMMUNOGLOBULIN VARIABLE REGIONS, which are part of the antigen-binding site, and the first IMMUNOGLOBULIN CONSTANT REGIONS. This fragment can be obtained by digestion of immunoglobulins with the proteolytic enzyme PAPAIN.

Immunoglobulin Fc Fragments [M0011127]
Crystallizable fragments composed of the carboxy-terminal halves of both IMMUNOGLOBULIN HEAVY CHAINS linked to each other by disulfide bonds. Fc fragments contain the carboxy-terminal parts of the heavy chain constant regions that are responsible for the effector functions of an immunoglobulin (COMPLEMENT fixation, binding to the cell membrane via FC RECEPTORS, and placental transport). This fragment can be obtained by digestion of immunoglobulins with the proteolytic enzyme PAPAIN.

Immunoglobulin Fragments [M0011106]
Partial immunoglobulin molecules resulting from selective cleavage by proteolytic enzymes or generated through PROTEIN ENGINEERING techniques.

Immunoglobulin G [M0376295]
The major immunoglobulin isotype class in normal human serum. There are several isotype subclasses of IgG, for example, IgG1, IgG2A, and IgG2B.

Immunoglobulin gamma-Chains [M0011131]
Heavy chains of IMMUNOGLOBULIN G having a molecular weight of approximately 51 kDa. They contain about 450 amino acid residues arranged in four domains and an oligosaccharide component covalently bound to the Fc fragment constant region. The gamma heavy chain subclasses (for example, gamma 1, gamma 2a, and gamma 2b) of the IMMUNOGLOBULIN G isotype subclasses (IgG1, IgG2A, and IgG2B) resemble each other more closely than the heavy chains of the other IMMUNOGLOBULIN ISOTYPES.

Immunoglobulin Heavy Chain Subgroup VH-I [M0011132]

Immunoglobulin Heavy Chain Subgroup VH-III [M0011133]

Immunoglobulin Heavy Chains [M0011134]
The largest of polypeptide chains comprising immunoglobulins. They contain 450 to 600 amino acid residues per chain, and have molecular weights of 51-72 kDa.

Immunoglobulin Idiotypes [M0011109]
Unique, genetically controlled determinants present on ANTIBODIES whose specificity is limited to a single group of proteins (e.g., another antibody molecule or an individual myeloma protein). The idiotype appears to represent the antigenicity of the antigen-binding site of the antibody and to be genetically codetermined with it. The idiotypic determinants have been precisely located to the IMMUNOGLOBULIN VARIABLE REGION of both immunoglobin polypeptide chains.

Immunoglobulin Isotypes [M0011111]
The classes of immunoglobulins found in any species of animal. In man there are nine classes that migrate in five different groups in electrophoresis; they each consist of two light and two heavy protein chains, and each group has distinguishing structural and functional properties.

Immunoglobulin J Recombination Signal Sequence-Binding Protein [M0195115]
A ubiquitously expressed sequence-specific transcriptional repressor that is normally the target of signaling by NOTCH PROTEINS.

Immunoglobulin J-Chains [M0011135]
A 15 kD "joining" peptide that forms one of the linkages between monomers of IMMUNOGLOBULIN A or IMMUNOGLOBULIN M in the formation of polymeric immunoglobulins. There is one J chain per one IgA dimer or one IgM pentamer. It is also involved in binding the polymeric immunoglobulins to POLYMERIC IMMUNOGLOBULIN RECEPTOR which is necessary for their transcytosis to the lumen. It is distinguished from the IMMUNOGLOBULIN JOINING REGION which is part of the IMMUNOGLOBULIN VARIABLE REGION of the immunoglobulin light and heavy chains.

Immunoglobulin Joining Region Peptide Fragments [M0481959]

Immunoglobulin kappa-Chains [M0011136]
One of the types of light chains of the immunoglobulins with a molecular weight of approximately 22 kDa.

Immunoglobulin lambda-Chains [M0011139]
One of the types of light chain subunits of the immunoglobulins with a molecular weight of approximately 22 kDa.

Immunoglobulin Light Chains [M0011143]
Polypeptide chains, consisting of 211 to 217 amino acid residues and having a molecular weight of approximately 22 kDa. There are two major types of light chains, kappa and lambda. Two Ig light chains and two Ig heavy chains (IMMUNOGLOBULIN HEAVY CHAINS) make one immunoglobulin molecule.

Immunoglobulin M [M0011019]
A class of immunoglobulin bearing mu chains (IMMUNOGLOBULIN MU-CHAINS). IgM can fix COMPLEMENT. The name comes from its high molecular weight and originally being called a macroglobulin.

Immunoglobulin mu-Chains [M0011144]
The class of heavy chains found in IMMUNOGLOBULIN M. They have a molecular weight of approximately 72 kDa and they contain about 57 amino acid residues arranged in five domains and have more oligosaccharide branches and a higher carbohydrate content than the heavy chains of IMMUNOGLOBULIN G.

Immunoglobulin Recombinases [M0182647]

Immunoglobulin Subunits [M0475481]
The PROTEIN SUBUNITS of the multimeric IMMUNOGLOBULIN proteins, such as IGA; IGD; IGE; IGG; and IGM. Included are the heavy and light chains which contain the specific ANTIGEN binding domains, as well as the accessory proteins that are part of the the secreted forms of IGM and IGA; (SECRETORY IGA).

Immunoglobulin Variable Region [M0011118]
That region of the immunoglobulin molecule that varies in its amino acid sequence and composition, and comprises the binding site for a specific antigen. It is located at the N-terminus of the Fab fragment of the immunoglobulin. It includes hypervariable regions (COMPLEMENTARITY DETERMINING REGIONS) and framework regions.

Immunoglobulins [M0011122]
Multi-subunit proteins which function in IMMUNITY. They are produced by B LYMPHOCYTES from the IMMUNOGLOBULIN GENES. They are comprised of two heavy (IMMUNOGLOBULIN HEAVY CHAINS) and two light chains (IMMUNOGLOBULIN LIGHT CHAINS) with additional ancillary polypeptide chains depending on their isoforms. The variety of isoforms include monomeric or polymeric forms, and transmembrane forms (B-CELL ANTIGEN RECEPTORS) or secreted forms (ANTIBODIES). They are divided by the amino acid sequence of their heavy chains into five classes (IMMUNOGLOBULIN A; IMMUNOGLOBULIN D; IMMUNOGLOBULIN E; IMMUNOGLOBULIN G; IMMUNOGLOBULIN M) and various subclasses.

Immunoglobulins, Intravenous [M0025515]
Immunoglobulin preparations used in intravenous infusion, containing primarily IMMUNOGLOBULIN G. They are used to treat a variety of diseases associated with decreased or abnormal immunoglobulin levels including pediatric AIDS; primary HYPERGAMMAGLOBULINEMIA; SCID; CYTOMEGALOVIRUS infections in transplant recipients, LYMPHOCYTIC LEUKEMIA, CHRONIC; Kawasaki syndrome, infection in neonates, and IDIOPATHIC THROMBOCYTOPENIC PURPURA.

Immunoglobulins, Thyroid-Stimulating [M0028182]
Autoantibodies that bind to the thyroid-stimulating hormone (TSH) receptor (RECEPTORS, THYROTROPIN) on thyroid epithelial cells. The autoantibodies mimic TSH causing an unregulated production of thyroid hormones characteristic of GRAVES DISEASE.

Immunophilins [M0029838]
Members of a family of highly conserved proteins which are all cis-trans peptidyl-prolyl isomerases (PEPTIDYLPROLYL ISOMERASE). They bind the immunosuppressant drugs CYCLOSPORINE; TACROLIMUS and SIROLIMUS. They possess rotomase activity, which is inhibited by the immunosuppressant drugs that bind to them.

Immunoproteins [M0011167]
Blood proteins whose activities affect or play a role in the functioning of the immune system.

IMP Dehydrogenase [M0011173]
An enzyme that catalyzes the dehydrogenation of inosine 5'-phosphate to xanthosine 5'-phosphate in the presence of NAD. EC 1.1.1.205.

Importins [M0240471]
A subclass of karyopherins that function specifically to import molecules into the nucleus.

In-Transferrin [M0021804]

Inactivated C3b [M0004931]

Indian Hedgehog Protein [M0235915]

Indole-3-Glycerol-Phosphate Synthase [M0011236]
An enzyme in the tryptophan biosynthetic pathway. EC 4.1.1.48.

Indoleamine-Pyrrole 2,3,-Dioxygenase [M0475654]
A dioxygenase with specificity for the oxidation of the indoleamine ring of TRYPTOPHAN. It is an extrahepatic enzyme that plays a role in metabolism as the first and rate limiting enzyme in the kynurenine pathway of TRYPTOPHAN catabolism.

Influenza Virus Core Proteins [M0022699]

Ingensin [M0140417]

Inhibin-beta Subunits [M0381770]
They are glycopeptides and subunits in INHIBINS and ACTIVINS. Inhibins and activins belong to the transforming growth factor beta superfamily.

Inhibins [M0011340]
Glycoproteins that inhibit pituitary FOLLICLE STIMULATING HORMONE secretion. Inhibins are secreted by the Sertoli cells of the testes, the granulosa cells of the ovarian follicles, the placenta, and other tissues. Inhibins and ACTIVINS are modulators of FOLLICLE STIMULATING HORMONE secretions; both groups belong to the TGF-beta superfamily, as the TRANSFORMING GROWTH FACTOR BETA. Inhibins consist of a disulfide-linked heterodimer with a unique alpha linked to either a beta A or a beta B subunit to form inhibin A or inhibin B, respectively

Inhibins, Female [M0011339]

Inhibins, Testicular [M0011343]

Inhibitor of Apoptosis 1 Protein [M0479024]

Inhibitor of Apoptosis 2 Protein [M0479026]

Inhibitor of Apoptosis Proteins [M0283555]
A conserved class of proteins that control APOPTOSIS in both VERTEBRATES and INVERTEBRATES. IAP proteins interact with and inhibit CASPASES, and they function as ANTI-APOPTOTIC PROTEINS. The protein class is defined by an approximately 80-amino acid motif called the baculoviral inhibitor of apoptosis repeat.

Inhibitor of Differentiation Protein 1 [M0175487]
A negative regulator of BASIC HELIX-LOOP-HELIX TRANSCRIPTION FACTORS that blocks activation of CYCLIN-DEPENDENT KINASE INHIBITOR P16 and is de-regulated in a variety of NEOPLASMS.

Inhibitor of Differentiation Protein 2 [M0197427]
A negative regulator of BASIC HELIX-LOOP-HELIX TRANSCRIPTION FACTORS. It plays a role in regulating IMMUNOGLOBULIN E expression.

Inhibitor of Differentiation Proteins [M0481860]
Inhibitor of differentiation proteins are negative regulators of BASIC HELIX-LOOP-HELIX TRANSCRIPTION FACTORS. They inhibit CELL DIFFERENTIATION and induce CELL PROLIFERATION by modulating different CELL CYCLE regulators.

Iniprol [M0011911]

INK4 Cyclin-Dependent Kinase Inhibitors [M0477631]
A family of cell cycle proteins containing ANKYRIN REPEATS that are specific inhibitors of cyclin D-dependent kinases. INK4 proteins bind to CYCLIN-DEPENDENT KINASE 4 and CYCLIN-DEPENDENT KINASE 6. They dissociate cyclin-CDK complexes and regulate a CELL CYCLE checkpoint in early G1 PHASE.

Inorganic Pyrophosphatase [M0086319]
An enzyme which catalyzes the hydrolysis of diphosphate (DIPHOSPHATES) into inorganic phosphate. The hydrolysis of pyrophosphate is coupled to the transport of HYDROGEN IONS across a membrane.

Inositol 1,4,5-trisphosphate Receptor Type 1 [M0138351]

Inositol 1,4,5-trisphosphate Receptor Type 2 [M0466162]

Inositol 1,4,5-trisphosphate Receptor Type 3 [M0138357]

Inositol 1,4,5-Trisphosphate Receptors [M0138366]
Intracellular receptors that bind to INOSITOL 1,4,5-TRISPHOSPHATE and play an important role in its intracellular signaling. Inositol 1,4,5-trisphosphate receptors are calcium channels that release CALCIUM in response to increased levels of inositol 1,4,5-trisphosphate in the CYTOPLASM.

Inositol Oxygenase [M0077196]
A non-heme IRON enzyme that catalyzes the conversion of MYOINOSITOL to D-glucuronic acid. The reaction is the first committed step in MYOINOSITOL catabolic pathway. This enzyme was formerly characterized as EC 1.13.1.11 and 1.99.2.6.

Insect Proteins [M0028968]
Proteins found in any species of insect.

Insulin [M0011417]
A 51-amino acid pancreatic hormone that plays a major role in the regulation of glucose metabolism, directly by suppressing endogenous glucose production (GLYCOGENOLYSIS; GLUCONEOGENESIS) and indirectly by suppressing GLUCAGON secretion and LIPOLYSIS. Native insulin is a globular protein comprised of a zinc-coordinated hexamer. Each insulin monomer containing two chains, A (21 residues) and B (30 residues), linked by two disulfide bonds. Insulin is used as a drug to control insulin-dependent diabetes mellitus (DIABETES MELLITUS, TYPE 1).

Insulin A Chain [M0011418]

Insulin Novo Monotard [M0392724]

Insulin Receptor alpha Subunit [M0331647]

Insulin Receptor beta Subunit [M0331648]

Insulin, Globin Zinc [M0011419]

Insulin, Isophane [M0011436]
A modified form of insulin that contains protamine and zinc. Isophane insulin is an intermediate-acting INSULIN with time of onset of 2 hours and duration of 24 hours.

Insulin, Lente [M0011437]
Sterile suspension, in a buffered water medium, of insulin modified by the addition of zinc chloride in a manner such that the solid phase of the suspension consists of a mixture of crystals and amorphous material in a ratio of approximately 7:3. (From The Merck Index, 11th ed, p4888)

Insulin, Lente, Monocomponent [M0392725]

Insulin, Monotard [M0392723]

Insulin, Protamine Zinc [M0011440]
A long-acting, modified form of INSULIN containing protamine and zinc. Its duration of action lasts up to 36 hours.

Insulin, Protamine Zinc, Beef-Pork [M0423929]

Insulin, Regular, Beef-Pork [M0423851]

Insulin, Regular, Human [M0423852]

Insulin, Regular, Pork [M0423949]

Insulin, Semilente [M0011438]

Insulin-Like Growth Factor Binding Protein 1 [M0028341]
One of the six homologous proteins that specifically bind insulin-like growth factors (SOMATOMEDINS) and modulate their mitogenic and metabolic actions. The function of this protein is not completely defined. However, several studies demonstrate that it inhibits IGF binding to cell surface receptors and thereby inhibits IGF-mediated mitogenic and cell metabolic actions. (Proc Soc Exp Biol Med 1993;204(1):4-29)

Insulin-Like Growth Factor Binding Protein 2 [M0028342]
One of the six homologous soluble proteins that bind insulin-like growth factors (SOMATOMEDINS) and modulate their mitogenic and metabolic actions at the cellular level.

Insulin-Like Growth Factor Binding Protein 3 [M0028343]
One of the six homologous soluble proteins that bind insulin-like growth factors (SOMATOMEDINS) and modulate their mitogenic and metabolic actions at the cellular level.

Insulin-Like Growth Factor Binding Protein 4 [M0028345]
One of the six homologous soluble proteins that bind insulin-like growth factors (SOMATOMEDINS) and modulate their mitogenic and metabolic actions at the cellular level.

Insulin-Like Growth Factor Binding Protein 5 [M0028346]
One of the six homologous soluble proteins that bind insulin-like growth factors (SOMATOMEDINS) and modulate their mitogenic and metabolic actions at the cellular level.

Insulin-Like Growth Factor Binding Protein 6 [M0028347]
One of the six homologous soluble proteins that bind insulin-like growth factors (SOMATOMEDINS) and modulate their mitogenic and metabolic actions at the cellular level.

Insulin-Like Growth Factor Binding Proteins [M0028340]
A family of soluble proteins that bind insulin-like growth factors and modulate their biological actions at the cellular level. (Int J Gynaecol Obstet 1992;39(1):3-9)

Insulin-Like Growth Factor I [M0011434]
A well-characterized basic peptide believed to be secreted by the liver and to circulate in the blood. It has growth-regulating, insulin-like, and mitogenic activities. This growth factor has a major, but not absolute, dependence on GROWTH HORMONE. It is believed to be mainly active in adults in contrast to INSULIN-LIKE GROWTH FACTOR II, which is a major fetal growth factor.

Insulin-Like Growth Factor II [M0011435]
A well-characterized neutral peptide believed to be secreted by the LIVER and to circulate in the BLOOD. It has growth-regulating, insulin-like and mitogenic activities. The growth factor has a major, but not absolute, dependence on SOMATOTROPIN. It is believed to be a major fetal growth factor in contrast to INSULIN-LIKE GROWTH FACTOR I, which is a major growth factor in adults.

Insulysin [M0011443]
An enzyme the catalyzes the degradation of insulin, glucagon and other polypeptides. It is inhibited by bacitracin, chelating agents EDTA and 1,10-phenanthroline, and by thiol-blocking reagents such as N-ethylmaleimide, but not phosphoramidon. (Eur J Biochem 1994;223:1-5) EC 3.4.24.56.

Integral Membrane Proteins [M0013340]

Integrases [M0028900]
Recombinases that insert exogenous DNA into the host genome. Examples include proteins encoded by the POL GENE of RETROVIRIDAE and also by temperate BACTERIOPHAGES, the best known being BACTERIOPHAGE LAMBDA.

Integration Host Factor alpha Subunit [M0129438]

Integration Host Factor beta Subunit [M0129439]

Integration Host Factors [M0129443]
Bacterial proteins that are used by BACTERIOPHAGES to incorporate their DNA into the DNA of the "host" bacteria. They are DNA-binding proteins that function in genetic recombination as well as in transcriptional and translational regulation.

Integrin alpha Chains [M0417909]
The alpha subunits of integrin heterodimers (INTEGRINS), which mediate ligand specificity. There are approximately 18 different alpha chains, exhibiting great sequence diversity; several chains are also spliced into alternative isoforms. They possess a long extracellular portion (1200 amino acids) containing a MIDAS (metal ion-dependent adhesion site) motif, and seven 60-amino acid tandem repeats, the last 4 of which form EF HAND MOTIFS. The intracellular portion is short (>50 AA) with the exception of INTEGRIN ALPHA4.

Integrin alpha1 [M0230956]
An integrin alpha subunit that binds COLLAGEN and LAMININ though its I domain. It combines with INTEGRIN BETA1 to form the heterodimer INTEGRIN ALPHA1BETA1.

Integrin alpha1beta1 [M0230961]
Integrin alpha1beta1 functions as a receptor for LAMININ and COLLAGEN. It is widely expressed during development, but in the adult is the predominant laminin receptor (RECEPTORS, LAMININ) in mature SMOOTH MUSCLE CELLS, where it is important for maintenance of the differentiated phenotype of these cells. Integrin alpha1beta1 is also found in LYMPHOCYTES and microvascular endothelial cells, and may play a role in angiogenesis. In SCHWANN CELLS and neural crest cells, it is involved in cell migration. Integrin alpha1beta1 is also known as VLA-1 and CD49a-CD29.

Integrin alpha2 [M0224331]
An integrin alpha subunit that primarily combines with INTEGRIN BETA1 to form the INTEGRIN ALPHA2BETA1 heterodimer. It contains a domain which has homology to collagen-binding domains found in von Willebrand factor.

Integrin alpha2beta1 [M0417889]
An integrin found on fibroblasts, platelets, endothelial and epithelial cells, and lymphocytes where it functions as a receptor for COLLAGEN and LAMININ. Although originally referred to as the collagen receptor, it is one of several receptors for collagen. Ligand binding to integrin alpha2beta1 triggers a cascade of intracellular signaling, including activation of p38 MAP kinase.

Integrin alpha3 [M0246637]
An integrin alpha subunit that occurs as alternatively spliced isoforms. The isoforms are differentially expressed in specific cell types and at specific developmental stages. Integrin alpha3 combines with INTEGRIN BETA1 to form INTEGRIN ALPHA3BETA1 which is a heterodimer found primarily in epithelial cells.

Integrin alpha3beta1 [M0199874]
Cell surface receptor for LAMININ, epiligrin, FIBRONECTINS, entactin, and COLLAGEN. Integrin alpha3beta1 is the major integrin present in EPITHELIAL CELLS, where it plays a role in the assembly of BASEMENT MEMBRANE as well as in cell migration, and may regulate the functions of other integrins. Two alternatively spliced isoforms of the alpha subunit (INTEGRIN ALPHA3), are differentially expressed in different cell types.

Integrin alpha4 [M0228076]
An integrin alpha subunit that is unique in that it does not contain an I domain, and its proteolytic cleavage site is near the middle of the extracellular portion of the polypeptide rather than close to the membrane as in other integrin alpha subunits.

Integrin alpha4beta1 [M0184906]
Integrin alpha4beta1 is a FIBRONECTIN and VCAM-1 receptor present on LYMPHOCYTES; MONOCYTES; EOSINOPHILS; NK CELLS and thymocytes. It is involved in both cell-cell and cell- EXTRACELLULAR MATRIX adhesion and plays a role in INFLAMMATION, hematopoietic cell homing and immune function, and has been implicated in skeletal MYOGENESIS; NEURAL CREST migration and proliferation, lymphocyte maturation and morphogenesis of the PLACENTA and HEART.

Integrin alpha5 [M0247642]
This integrin alpha subunit combines with INTEGRIN BETA1 to form a receptor (INTEGRIN ALPHA5BETA1) that binds FIBRONECTIN and LAMININ. It undergoes posttranslational cleavage into a heavy and a light chain that are connected by disulfide bonds.

Integrin alpha5beta1 [M0418249]
An integrin found in FIBROBLASTS; PLATELETS; MONOCYTES, and LYMPHOCYTES. Integrin alpha5beta1 is the classical receptor for FIBRONECTIN, but it also functions as a receptor for LAMININ and several other EXTRACELLULAR MATRIX PROTEINS.

Integrin alpha6 [M0237213]
An integrin alpha subunit that primarily associates with INTEGRIN BETA1 or INTEGRIN BETA4 to form laminin-binding heterodimers. Integrin alpha6 has two alternatively spliced isoforms: integrin alpha6A and integrin alpha6B, which differ in their cytoplasmic domains and are regulated in a tissue-specific and developmental stage-specific manner.

Integrin alpha6A [M0237211]

Integrin alpha6Abeta1 [M0208149]

Integrin alpha6B [M0237212]

Integrin alpha6Bbeta1 [M0208150]

Integrin alpha6beta1 [M0208151]
A cell surface receptor mediating cell adhesion to the EXTRACELLULAR MATRIX and to other cells via binding to LAMININ. It is involved in cell migration, embryonic development, leukocyte activation and tumor cell invasiveness. Integrin alpha6beta1 is the major laminin receptor on PLATELETS; LEUKOCYTES; and many EPITHELIAL CELLS, and ligand binding may activate a number of signal transduction pathways. Alternative splicing of the cytoplasmic domain of the alpha6 subunit (INTEGRIN ALPHA6) results in the formation of A and B isoforms of the heterodimer, which are expressed in a tissue-specific manner.

Integrin alpha6beta4 [M0154541]
This intrgrin is a key component of HEMIDESMOSOMES and is required for their formation and maintenance in epithelial cells. Integrin alpha6beta4 is also found on thymocytes, fibroblasts, and Schwann cells, where it functions as a laminin receptor (RECEPTORS, LAMININ) and is involved in wound healing, cell migration, and tumor invasiveness.

Integrin alphaV [M0230139]
An alpha integrin with a molecular weight of 160-kDa that is found in a variety of cell types. It undergoes posttranslational cleavage into a heavy and a light chain that are connected by disulfide bonds. Integrin alphaV can combine with several different beta subunits to form heterodimers that generally bind to RGD sequence-containing extracellular matrix proteins.

Integrin alphaVbeta3 [M0418730]
An integrin that binds to a variety of plasma and extracellular matrix proteins containing the conserved RGD amino acid sequence and modulates cell adhesion. Integrin alphavbeta3 is highly expressed in OSTEOCLASTS where it may play role in BONE RESORPTION. It is also abundant in vascular smooth muscle and endothelial cells, and in some tumor cells, where it is involved in angiogenesis and cell migration. Although often referred to as the vitronectin receptor there is more than one receptor for vitronectin (RECEPTORS, VITRONECTIN).

Integrin alphaXbeta2 [M0024681]
A major adhesion-associated heterodimer molecule expressed by MONOCYTES; GRANULOCYTES; NK CELLS; and some LYMPHOCYTES. The alpha subunit is the CD11C ANTIGEN, a surface antigen expressed on some myeloid cells. The beta subunit is the CD18 ANTIGEN.

Integrin beta Chains [M0419369]
Integrin beta chains combine with integrin alpha chains to form heterodimeric cell surface receptors. Integrins have traditionally been classified into functional groups based on the identity of one of three beta chains present in the heterodimer. The beta chain is necessary and sufficient for integrin-dependent signaling. Its short cytoplasmic tail contains sequences critical for inside-out signaling.

Integrin beta3 [M0166703]
An integrin beta subunit of approximately 85-kDa in size which has been found in INTEGRIN ALPHAIIB-containing and INTEGRIN ALPHAV-containing heterodimers. Integrin beta3 occurs as three alternatively spliced isoforms, designated beta3A-C.

Integrin beta3A [M0383917]

Integrin beta3B [M0420673]

Integrin beta3C [M0420674]

Integrin beta4 [M0230108]
Also known as CD104 antigen, this protein is distinguished from other beta integrins by its relatively long cytoplasmic domain (approximately 1000 amino acids vs. approximately 50). Five alternatively spliced isoforms have been described.

Integrins [M0024497]
A family of transmembrane glycoproteins (MEMBRANE GLYCOPROTEINS) consisting of noncovalent heterodimers. They interact with a wide variety of ligands including EXTRACELLULAR MATRIX PROTEINS; COMPLEMENT, and other cells, while their intracellular domains interact with the CYTOSKELETON. The integrins consist of at least three identified families: the cytoadhesin receptors(RECEPTORS, CYTOADHESIN), the leukocyte adhesion receptors (RECEPTORS, LEUKOCYTE ADHESION), and the VERY LATE ANTIGEN RECEPTORS. Each family contains a common beta-subunit (INTEGRIN BETA CHAINS) combined with one or more distinct alpha-subunits (INTEGRIN ALPHA CHAINS). These receptors participate in cell-matrix and cell-cell adhesion in many physiologically important processes, including embryological development; HEMOSTASIS; THROMBOSIS; WOUND HEALING; immune and nonimmune defense mechanisms; and oncogenic transformation.

Inteins [M0458475]
The internal fragments of precursor proteins (INternal proTEINS) that are autocatalytically removed by PROTEIN SPLICING. The flanking fragments (EXTEINS) are ligated forming mature proteins. The nucleic acid sequences coding for inteins are considered to be MOBILE GENETIC ELEMENTS. Inteins are composed of self-splicing domains and an endonuclease domain which plays a role in the spread of the intein's genomic sequence. Mini-inteins are composed of the self-splicing domains only.

Intercellular Adhesion Molecule-1 [M0028145]
A cell-surface ligand involved in leukocyte adhesion and inflammation. Its production is induced by gamma-interferon and it is required for neutrophil migration into inflamed tissue.

Intercellular Adhesion Molecules [M0024223]

Intercellular Signaling Peptides and Proteins [M0409590]
Regulatory proteins and peptides that are signaling molecules involved in the process of PARACRINE COMMUNICATION. They are generally considered factors that are expressed by one cell and are responded to by receptors on another nearby cell. They are distinguished from HORMONES in that their actions are local rather than distal.

Interferon Alfa, Recombinant [M0023690]

Interferon Alfa-2a [M0023693]
A recombinant alfa interferon consisting of 165 amino acids with lysine at position 23 and histidine at position 34. It is used extensively as an antiviral and antineoplastic agent.

Interferon Alfa-2b [M0023695]
A recombinant alfa interferon consisting of 165 amino acid residues with arginine in position 23 and histidine in position 34. It is used extensively as an antiviral and antineoplastic agent.

Interferon Alfa-2c [M0328205]
A recombinant alfa interferon consisting of 165 amino acids with arginine at positions 23 and 34. It is used extensively as an antiviral and antineoplastic agent.

Interferon Alfa-n1 [M0025713]

Interferon alpha-beta Receptor Chain 1 [M0495181]

Interferon alpha-beta Receptor Chain 2 [M0495180]

Interferon Beta, Recombinant [M0331755]

Interferon gamma-1b [M0329535]

Interferon gamma-2a [M0331836]

Interferon Regulatory Factor-1 [M0166190]
An interferon regulatory factor that binds upstream TRANSCRIPTIONAL REGULATORY ELEMENTS in the GENES for INTERFERON-ALPHA and INTERFERON-BETA. It functions as a transcriptional activator for the INTERFERON TYPE I genes.

Interferon Regulatory Factor-2 [M0168818]
An interferon regulatory factor that represses transcription of TYPE I INTERFERONS and activates transcription of HISTONE H4.

Interferon Regulatory Factor-3 [M0255479]
An interferon regulatory factor that is expressed constitutively and undergoes POST-TRANSLATIONAL MODIFICATION following viral infection. PHOSPHORYLATION of IRF-3 causes the protein to be translocated from the CYTOPLASM to CELL NUCLEUS where it binds DNA, and activates transcription.

Interferon Regulatory Factor-7 [M0281722]
An interferon regulatory factor that is induced by INTERFERONS as well as LMP-1 protein from EPSTEIN-BARR VIRUS. IRF-7 undergoes PHOSPHORYLATION prior to nuclear translocation and it activates GENETIC TRANSCRIPTION of multiple interferon GENES.

Interferon Regulatory Factors [M0478209]
A family of transcription factors that share an N-terminal HELIX-TURN-HELIX MOTIF and bind INTERFERON-inducible PROMOTERS to control GENE expression. IRF proteins bind specific DNA sequences such as interferon-stimulated response elements, interferon regulatory elements, and the interferon consensus sequence.

Interferon Type I [M0011489]
Interferon secreted by leukocytes, fibroblasts, or lymphoblasts in response to viruses or interferon inducers other than mitogens, antigens, or allo-antigens. They include alpha- and beta-interferons (INTERFERON-ALPHA and INTERFERON-BETA).

Interferon Type I, Recombinant [M0023692]
A type I interferon with antiviral and antineoplastic activity produced by recombinant DNA technology. It can be a mixture of alpha and beta interferons.

Interferon Type II [M0011490]
The major interferon produced by mitogenically or antigenically stimulated lymphocytes. It is structurally different from type I interferon (INTERFERON TYPE I) and its major activity is immunoregulation. It has been implicated in the expression of class II histocompatibility antigens in cells that do not normally produce them, leading to autoimmune disease.

Interferon-alpha [M0025711]
One of the type I interferons (INTERFERON TYPE I) produced by peripheral blood leukocytes or lymphoblastoid cells when exposed to live or inactivated virus, double-stranded RNA, or bacterial products. It is the major interferon produced by virus-induced leukocyte cultures and, in addition to its pronounced antiviral activity, it causes activation of NK cells.

Interferon-beta [M0025715]
One of the type I interferons produced by fibroblasts in response to stimulation by live or inactivated virus or by double-stranded RNA. It is a cytokine with antiviral, antiproliferative, and immunomodulating activity.

Interferon-gamma, Recombinant [M0023697]
A type II interferon produced by recombinant DNA technology. It is similar to the interferon secreted by lymphocytes and has antiviral and antineoplastic activity.

Interferon-Stimulated Gene Factor 3 [M0181861]
A multimeric complex that functions as a ligand-dependent transcription factor. ISGF3 is assembled in the CYTOPLASM and translocated to the CELL NUCLEUS in response to INTERFERON signaling. It consists of ISGF3-GAMMA and ISGF3-ALPHA, and it regulates expression of many interferon-responsive GENES.

Interferon-Stimulated Gene Factor 3, alpha Subunit [M0181857]
A heterodimeric complex of STAT1 PROTEIN and STAT2 PROTEIN that interacts with ISGF3GAMMA and is a subunit of the ISGF3 COMPLEX.

Interferon-Stimulated Gene Factor 3, gamma Subunit [M0181856]
An interferon regulatory factor that recruits STAT1 PROTEIN and STAT2 PROTEIN heterodimers to interferon-stimulated response elements and functions as an immediate-early protein.

Interferons [M0011491]
Proteins secreted by vertebrate cells in response to a wide variety of inducers. They confer resistance against many different viruses, inhibit proliferation of normal and malignant cells, impede multiplication of intracellular parasites, enhance macrophage and granulocyte phagocytosis, augment natural killer cell activity, and show several other immunomodulatory functions.

Interleukin 1 Receptor Antagonist Protein [M0148648]
A ligand that binds to but fails to activate the INTERLEUKIN-1 RECEPTOR. It plays an inhibitory role in the regulation of INFLAMMATION and FEVER. Several isoforms of the protein exist due to multiple ALTERNATIVE SPLICING of its mRNA.

Interleukin Receptor Common gamma Subunit [M0378698]
An interleukin receptor subunit that was originally discovered as a component of the INTERLEUKIN-2 RECEPTOR. It was subsequently found to be a component of several other receptors including the INTERLEUKIN-4 RECEPTOR, the INTERLEUKIN-7 RECEPTOR, the INTERLEUKIN-9 RECEPTOR, the INTERLEUKIN-15 RECEPTOR, and the INTERLEUKIN-21 RECEPTOR. Mutations in the gene for the interleukin common gamma chain have been associated with X-LINKED COMBINED IMMUNODEFICIENCY DISEASES.

Interleukin-1 [M0011503]
A soluble factor produced by MONOCYTES; MACROPHAGES, and other cells which activates T-lymphocytes and potentiates their response to mitogens or antigens. Interleukin-1 is a general term refers to either of the two distinct proteins, INTERLEUKIN-1ALPHA and INTERLEUKIN-1BETA. The biological effects of IL-1 include the ability to replace macrophage requirements for T-cell activation.

Interleukin-1 Receptor Accessory Protein [M0267317]
A protein that takes part in the formation of active interleukin-1 receptor complex. It binds specifically to INTERLEUKIN-1 and the TYPE-I INTERLEUKIN-1 RECEPTOR at the cell surface to form a heterotrimeric complex that brings its cytoplasmic domain into contact with the cytoplasm domain of the TYPE-I INTERLEUKIN-1 RECEPTOR. Activation of intracellular signal transduction pathways from the receptor is believed to be driven by this form of cytoplasmic interaction.

Interleukin-1 Receptor-Associated Kinase 1 [M0494872]

Interleukin-1 Receptor-Associated Kinase 2 [M0258080]

Interleukin-1 Receptor-Associated Kinase 3 [M0494874]

Interleukin-1 Receptor-Associated Kinase 4 [M0494876]

Interleukin-1 Receptor-Associated Kinases [M0258081]
A family of intracellular signaling kinases that were identified by their ability to signal from the activated INTERLEUKIN-1 RECEPTORS. Signaling from these kinases involves their interaction with SIGNAL TRANSDUCING ADAPTOR PROTEINS such as MYELOID DIFFERENTIATION FACTOR 88 and TNF RECEPTOR-ASSOCIATED FACTOR 6.

Interleukin-10 [M0025510]
A cytokine produced by a variety of cell types, including T-LYMPHOCYTES; MONOCYTES; DENDRITIC CELLS; and EPITHELIAL CELLS that exerts a variety of effects on immunoregulation and INFLAMMATION. Interleukin-10 combines with itself to form a homodimeric molecule that is the biologically active form of the protein.

Interleukin-10 Receptor alpha Subunit [M0495675]
A subunit of the interleukin-10 receptor. It plays a role in receptor signaling by associating with JANUS KINASE 1.

Interleukin-10 Receptor beta Subunit [M0495677]
A subunit of the interleukin-10 receptor. It plays a role in receptor signaling by associating with TYK2 KINASE.

Interleukin-11 [M0026381]
A lymphohematopoietic cytokine that plays a role in regulating the proliferation of ERYTHROID PROGENITOR CELLS. It induces maturation of MEGAKARYOCYTES which results in increased production of BLOOD PLATELETS. Interleukin-11 was also initially described as an inhibitor of ADIPOGENESIS of cultured preadipocytes.

Interleukin-11 Receptor alpha Subunit [M0495688]
A low affinity interleukin-11 receptor subunit that combines with the CYTOKINE RECEPTOR GP130 to form a high affinity receptor for INTERLEUKIN-11. Multiple isoforms of this protein exist due to ALTERNATIVE SPLICING of its MRNA.

Interleukin-12 [M0027969]
A heterodimeric cytokine that plays a role in innate and adaptive immune responses. Interleukin-12 is a 70 kDa protein that is composed of covalently linked 40 kDa and 35 kDa subunits. It is produced by DENDRITIC CELLS; MACROPHAGES and a variety of other immune cells and plays a role in the stimulation of INTERFERON GAMMA production by T-LYMPHOCYTES and NATURAL KILLER CELLS.

Interleukin-12 Receptor beta 1 Subunit [M0400264]
A subunit of the interleukin-12 receptor. It plays a role in receptor signaling by associating with TYK2 KINASE 1.

Interleukin-12 Receptor beta 2 Subunit [M0400265]
A subunit of the interleukin-12 receptor. It plays a role in receptor signaling by associating with JANUS KINASE 2.

Interleukin-12 Subunit p35 [M0419293]
A subunit of interleukin-12. It binds to the INTERLEUKIN-12 SUBUNIT P40 via a disulfide bond that results in the active cytokine.

Interleukin-12 Subunit p40 [M0419292]
A cytokine subunit that is a component of both interleukin-12 and interleukin-23. It binds to the INTERLEUKIN-12 SUBUNIT P35 via a disulfide bond to form interleukin-12 and to INTERLEUKIN-23 SUBUNIT P19 to form interleukin-23.

Interleukin-13 [M0028132]
A cytokine synthesized by T-LYMPHOCYTES that produces proliferation, immunoglobulin isotype switching, and immunoglobulin production by immature B-LYMPHOCYTES. It appears to play a role in regulating inflammatory and immune responses.

Interleukin-13 Receptor alpha1 Subunit [M0219129]
An interleukin receptor subunit with specificity for INTERLEUKIN-13. It dimerizes with the INTERLEUKIN-4 RECEPTOR ALPHA SUBUNIT to form the TYPE II INTERLEUKIN-4 RECEPTOR which has specificity for both INTERLEUKIN-4 and INTERLEUKIN-13. Signaling of this receptor subunit occurs through the interaction of its cytoplasmic domain with JANUS KINASES such as the TYK2 KINASE.

Interleukin-13 Receptor alpha2 Subunit [M0394837]
An interleukin-13 receptor subunit that is closely-related to the INTERLEUKIN-13 RECEPTOR ALPHA1 SUBUNIT. The receptor is found as a monomeric protein and has been considered to be a decoy receptor for interleukin-13 due the fact that it lacks cytoplasmic signaling domains.

Interleukin-15 [M0028879]
Cytokine that stimulates the proliferation of T-LYMPHOCYTES and shares biological activities with IL-2. IL-15 also can induce proliferation and differentiation of B-LYMPHOCYTES.

Interleukin-15 Receptor alpha Subunit [M0495171]
A low affinity interleukin-15 receptor subunit that combines with the INTERLEUKIN-2 RECEPTOR BETA SUBUNIT and the INTERLEUKIN RECEPTOR COMMON GAMMA-CHAIN to form a high affinity receptor for INTERLEUKIN-15.

Interleukin-16 [M0028880]
A cytokine produced by activated T-LYMPHOCYTES that stimulates the migration of CD4-POSITIVE LYMPHOCYTES and monocytes. It has been reported to suppress HIV replication.

Interleukin-17 [M0030025]
A proinflammatory cytokine produced primarily by T-LYMPHOCYTES or their precursors. Several subtypes of interleukin-17 have been identified, each of which is a product of a unique gene.

Interleukin-17 Receptor A [M0495842]

Interleukin-17 Receptor B [M0495838]
Specific for IL-17B and IL-17E

Interleukin-17 Receptor C [M0495839]

Interleukin-17 Receptor D [M0495840]

Interleukin-17 Receptor E [M0495841]

Interleukin-17A [M0495846]

Interleukin-17B [M0417589]

Interleukin-17C [M0495847]

Interleukin-17D [M0495854]

Interleukin-17E [M0495851]

Interleukin-17F [M0495852]

Interleukin-18 [M0030026]
A cytokine which resembles IL-1 structurally and IL-12 functionally. It enhances the cytotoxic activity of NK CELLS and CYTOTOXIC T-LYMPHOCYTES, and appears to play a role both as neuroimmunomodulator and in the induction of mucosal immunity.

Interleukin-18 Receptor alpha Subunit [M0495866]
A subunit of the interleukin-18 receptor that is responsible of extracellular binding of IL-18.

Interleukin-18 Receptor beta Subunit [M0495870]
A subunit of the interleukin-18 receptor that plays a role in receptor signaling by association of its cytoplasmic domain with SIGNAL TRANSDUCING ADAPTOR PROTEINS such as MYELOID DIFFERENTIATION FACTOR 88.

Interleukin-1alpha [M0011501]
An interleukin-1 subtype that occurs as a membrane-bound pro-protein form that is cleaved by proteases to form a secreted mature form. Unlike INTERLEUKIN-1BETA both membrane-bound and secreted forms of interleukin-1alpha are biologically active.

Interleukin-1beta [M0011502]
An interleukin-1 subtype that is synthesized as an inactive membrane-bound pro-protein. Proteolytic processing of the precursor form by CASPASE 1 results in release of the active form of interleukin-1beta from the membrane.

Interleukin-2 [M0011506]
A soluble substance elaborated by antigen- or mitogen-stimulated T-LYMPHOCYTES which induces DNA synthesis in naive lymphocytes.

Interleukin-2 Receptor alpha Subunit [M0404923]
A low affinity interleukin-2 receptor subunit that combines with the INTERLEUKIN-2 RECEPTOR BETA SUBUNIT and the INTERLEUKIN RECEPTOR COMMON GAMMA-CHAIN to form a high affinity receptor for INTERLEUKIN-2.

Interleukin-2 Receptor beta Subunit [M0393326]
A receptor subunit that is a shared component of the INTERLEUKIN 2 RECEPTOR and the INTERLEUKIN-15 RECEPTOR. High affinity receptor complexes are formed with each of these receptors when their respective alpha subunits are combined with this beta subunit and the INTERLEUKIN RECEPTOR COMMON GAMMA-CHAIN.

Interleukin-21 Receptor alpha Subunit [M0495958]
An interleukin-21 receptor subunit that combines with the INTERLEUKIN RECEPTOR COMMON GAMMA SUBUNIT to form a high affinity receptor for INTERLEUKIN-21. It signals via interaction of its cytoplasmic domain with JANUS KINASES such as JANUS KINASE 1 and JANUS KINASE 3.

Interleukin-23 [M0376076]
A heterodimeric cytokine that plays a role in innate and adaptive immune responses. Interleukin-23 is comprised of a unique 19 kDa subunit and 40 kDa subunit that is shared with INTERLEUKIN-12. It is produced by DENDRITIC CELLS; MACROPHAGES and a variety of other immune cells

Interleukin-23 Subunit p19 [M0453187]
A subunit of interleukin-23. It combines with INTERLEUKIN-12 SUBUNIT P40, which is shared between the two cytokines, to form in the active interleukin-23 cytokine.

Interleukin-3 [M0011508]
A multilineage cell growth factor secreted by LYMPHOCYTES; EPITHELIAL CELLS; and ASTROCYTES which stimulates clonal proliferation and differentiation of various types of blood and tissue cells.

Interleukin-3 Receptor alpha Subunit [M0495195]
A low affinity interleukin-3 receptor subunit that combines with the CYTOKINE RECEPTOR COMMON BETA SUBUNIT to form a high affinity receptor for INTERLEUKIN-3.

Interleukin-4 [M0024266]
A soluble factor produced by activated T-LYMPHOCYTES that induces the expression of MHC CLASS II GENES and FC RECEPTORS on B-LYMPHOCYTES and causes their proliferation and differentiation. It also acts on T-lymphocytes, MAST CELLS, and several other hematopoietic lineage cells.

Interleukin-4 Receptor alpha Subunit [M0495354]
A receptor subunit that is a component of the TYPE I INTERLEUKIN-4 RECEPTOR and the TYPE II INTERLEUKIN-4 RECEPTOR. It signals through interaction of its cytoplasmic domain with JANUS KINASES such as JANUS KINASE 1.

Interleukin-5 [M0024267]
A cytokine that promotes differentiation and activation of EOSINOPHILS. It also triggers activated B-LYMPHOCYTES to differentiate into IMMUNOGLOBULIN-secreting cells.

Interleukin-5 Receptor alpha Subunit [M0495420]
A low affinity interleukin-5 receptor subunit that combines with the CYTOKINE RECEPTOR COMMON BETA SUBUNIT to form a high affinity receptor for INTERLEUKIN-5. Several isoforms of the interleukin-5 receptor alpha subunit exist due to multiple ALTERNATIVE SPLICING.

Interleukin-6 [M0024272]
A cytokine that stimulates the growth and differentiation of B-LYMPHOCYTES and is also a growth factor for HYBRIDOMAS and plasmacytomas. It is produced by many different cells including T-LYMPHOCYTES; MONOCYTES; and FIBROBLASTS.

Interleukin-6 Receptor alpha Subunit [M0495574]
A low affinity interleukin-6 receptor subunit that combines with the CYTOKINE RECEPTOR GP130 to form a high affinity receptor for INTERLEUKIN-6.

Interleukin-7 [M0024273]
A cytokine produced by bone marrow stromal cells that promotes the growth of B-LYMPHOCYTE precursors and is co-mitogenic with INTERLEUKIN-2 for mature T-LYMPHOCYTE activation.

Interleukin-7 Receptor alpha Subunit [M0495659]
A low affinity interleukin-7 receptor subunit that combines with the INTERLEUKIN RECEPTOR COMMON GAMMA SUBUNIT to form a high affinity receptor for INTERLEUKIN-7.

Interleukin-8 [M0024750]
A member of the CXC chemokine family that plays a role in the regulation of the acute inflammatory response. It is secreted by variety of cell types and induces CHEMOTAXIS of NEUTROPHILS and other inflammatory cells.

Interleukin-9 [M0025726]
A multifunctional cytokine secreted by primarily by activated TH2 CELLS that may play a role as a regulator of allergic INFLAMMATION. It has been shown to enhance the growth and CELL DIFFERENTIATION of MAST CELLS, and can act on a variety of other immune cells.

Interleukins [M0011509]
Soluble factors which stimulate growth-related activities of leukocytes as well as other cell types. They enhance cell proliferation and differentiation, DNA synthesis, secretion of other biologically active molecules and responses to immune and inflammatory stimuli.

Intermediate Filament Proteins [M0011512]
Filaments 7-11 nm in diameter found in the cytoplasm of all cells. Many specific proteins belong to this group, e.g., desmin, vimentin, prekeratin, decamin, skeletin, neurofilin, neurofilament protein, and glial fibrillary acid protein.

Intermediate-Conductance Calcium-Activated Potassium Channels [M0282512]
A major class of calcium-activated potassium channels that were originally discovered in ERYTHROCYTES. They are found primarily in non-excitable CELLS and set up electrical gradients for PASSIVE ION TRANSPORT.

Intestinal Membrane Calcium-Binding Protein [M0003192]

Intracellular Calcium-Sensing Peptides [M0483399]

Intracellular Calcium-Sensing Proteins [M0483397]
Intracellular signaling peptides and proteins that bind to CALCIUM. They undergo allosteric changes when bound to CALCIUM that affects their interaction with other signal-transducing molecules. They differ from CALCIUM-SENSING RECEPTORS which sense extracellular calcium levels.

Intracellular Signaling Peptides [M0461969]

Intracellular Signaling Peptides and Proteins [M0460178]
Proteins and peptides that are involved in SIGNAL TRANSDUCTION within the cell. Included here are peptides and proteins that regulate the activity of TRANSCRIPTION FACTORS and cellular processes in response to signals from CELL SURFACE RECEPTORS. Intracellular signaling peptide and proteins may be part of an enzymatic signaling cascade or act through binding to and modifying the action of other signaling factors.

Intracellular Signaling Proteins [M0461970]

Intraglobin [M0025522]

Intraglobin F [M0025523]

Intramolecular Lyases [M0029318]
Enzymes of the isomerase class that catalyze reactions in which a group can be regarded as eliminated from one part of a molecule, leaving a double bond, while remaining covalently attached to the molecule. (From Enzyme Nomenclature, 1992) EC 5.5.

Intramolecular Oxidoreductases [M0029313]
Enzymes of the isomerase class that catalyze the oxidation of one part of a molecule with a corresponding reduction of another part of the same molecule. They include enzymes converting aldoses to ketoses (ALDOSE-KETOSE ISOMERASES), enzymes shifting a carbon-carbon double bond (CARBON-CARBON DOUBLE BOND ISOMERASES), and enzymes transposing S-S bonds (SULFUR-SULFUR BOND ISOMERASES). (From Enzyme Nomenclature, 1992) EC 5.3.

Intramolecular Transferases [M0029317]
Enzymes of the isomerase class that catalyze the transfer of acyl-, phospho-, amino- or other groups from one position within a molecule to another. EC 5.4.

Intrinsic Factor [M0011611]
A glycoprotein secreted by the cells of the GASTRIC GLANDS that is required for the absorption of Vitamin B 12 (CYANOCOBALAMIN). Deficiency of intrinsic factor leads to VITAMIN B 12 DEFICIENCY and ANEMIA, PERNICIOUS.

Intron A (Interferon) [M0023696]

Iodide Peroxidase [M0011629]
A hemeprotein that catalyzes the oxidation of the iodide radical to iodine with the subsequent iodination of many organic compounds, particularly proteins. EC 1.11.1.8.

Iodopeptides [M0011666]

Iodoproteins [M0011667]

Iodothyronine 5'-Deiodinase [M0011630]

Iodothyronine Deiodinase [M0011631]

Ion Channels [M0011674]
Gated, ion-selective glycoproteins that traverse membranes. The stimulus for channel gating can be a membrane potential, drug, transmitter, cytoplasmic messenger, or a mechanical deformation. Ion channels which are integral parts of ionotropic neurotransmitter receptors are not included.

Ion Pumps [M0025338]
A general class of integral membrane proteins that transport ions across a membrane against an electrochemical gradient.

IRF-7A Transcription Factor [M0281718]

IRF-7B Transcription Factor [M0281719]

IRF-7C Transcription Factor [M0281720]

Iron Regulatory Protein 1 [M0175229]
A multifunctional iron-sulfur protein that is both an iron regulatory protein and cytoplasmic form of aconitate hydratase. It binds to iron regulatory elements found on mRNAs involved in iron metabolism and regulates their translation. Its RNA binding ability and its aconitate hydrolase activity are dependent upon availability of IRON.

Iron Regulatory Protein 2 [M0175238]
A multifunctional iron-sulfur protein that is both an iron regulatory protein and cytoplasmic form of aconitate hydratase. It binds to iron regulatory elements found on mRNAs involved in iron metabolism and regulates their translation. Its rate of degradation is increased in the presence of IRON.

Iron Superoxide Dismutase [M0020830]

Iron-Binding Proteins [M0084824]
Proteins that specifically bind to IRON.

Iron-Regulatory Proteins [M0175241]
Proteins that regulate cellular and organismal iron homeostasis. They play an important biological role by maintaining iron levels that are adequate for metabolic need, but below the toxicity threshold.

Iron-Responsive Element Binding Proteins [M0175240]

Iron-Sulfur Proteins [M0011725]
A group of proteins possessing only the iron-sulfur complex as the prosthetic group. These proteins participate in all major pathways of electron transport: photosynthesis, respiration, hydroxylation and bacterial hydrogen and nitrogen fixation.

Isoactin [M0000302]

Isoamylase [M0011746]
An enzyme that hydrolyzes 1,6-alpha-glucosidic branch linkages in glycogen, amylopectin, and their beta-limit dextrins. It is distinguished from pullulanase (EC 3.2.1.41) by its inability to attack pullulan and by the feeble action of alpha-limit dextrins. It is distinguished from amylopectin 6-glucanohydrolase (EC 3.2.1.69) by its action on glycogen. With EC 3.2.1.69, it produces the activity called "debranching enzyme". EC 3.2.1.68.

Isoaspartate [M0378611]

Isoaspartic Acid [M0370917]
An ASPARTIC ACID residue in polypeptide chains that is linked at the beta-carboxyl group instead of at the normal, alpha-carboxyl group, polypeptide linkage. It is a result of the spontaneous decomposition of aspartic acid or ASPARAGINE residues.

Isocitrate Dehydrogenase [M0011751]
An enzyme of the oxidoreductase class that catalyzes the conversion of isocitrate and NAD+ to yield 2-ketoglutarate, carbon dioxide, and NADH. It occurs in cell mitochondria. The enzyme requires Mg2+, Mn2+; it is activated by ADP, citrate, and Ca2+, and inhibited by NADH, NADPH, and ATP. The reaction is the key rate-limiting step of the citric acid (tricarboxylic) cycle. (From Dorland, 27th ed) (The NADP+ enzyme is EC 1.1.1.42.) EC 1.1.1.41.

Isocitrate Dehydrogenase-I [M0011752]

Isocitrate Lyase [M0011753]
A key enzyme in the glyoxylate cycle. It catalyzes the conversion of isocitrate to succinate and glyoxylate. EC 4.1.3.1.

Isodesmosine [M0011755]
2-(4-Amino-4-carboxybutyl)-1-(5-amino-5-carboxypentyl)-3,5-bis(3-amino-3-carboxypropyl)pyridinium. A rare amino acid found in elastin, formed by condensation of four molecules of lysine into a pyridinium ring.

Isoenzymes [M0011758]
One of various structurally related forms of an enzyme, each having the same mechanism but with differing chemical, physical, or immunological characteristics.

Isoferritin [M0041688]

Isolectins [M0074850]
Lectin isoforms.

Isoleucine [M0011766]
An essential branched-chain aliphatic amino acid found in many proteins. It is an isomer of LEUCINE. It is important in hemoglobin synthesis and regulation of blood sugar and energy levels.

Isoleucine-tRNA Ligase [M0011767]
An enzyme that activates isoleucine with its specific transfer RNA. EC 6.1.1.5.

Isomerases [M0011769]
A class of enzymes that catalyze geometric or structural changes within a molecule to form a single product. The reactions do not involve a net change in the concentrations of compounds other than the substrate and the product.(from Dorland, 28th ed) EC 5.

Isometallothionein [M0013506]

Isophane Insulin, Beef [M0423934]

Isophane Insulin, Beef-Pork [M0423753]

Isophane Insulin, Human [M0423933]

Isophane Insulin, Pork [M0423932]

Isotransferrin [M0021805]

Isovaleryl-CoA Dehydrogenase [M0076387]
A mitochondrial flavoprotein, this enzyme catalyzes the oxidation of 3-methylbutanoyl-CoA to 3-methylbut-2-enoyl-CoA using FAD as a cofactor. Defects in the enzyme, is associated with isovaleric acidemia (IVA).

Isovinculin [M0025315]

Iveegam [M0025524]

J1-200-220 [M0373923]

Janus Kinase 1 [M0203027]
A Janus kinase subtype that is involved in signaling from a broad variety of CYTOKINE RECEPTORS.

Janus Kinase 2 [M0203030]
A Janus kinase subtype that is involved in signaling from GROWTH HORMONE RECEPTORS; PROLACTIN RECEPTORS; and a variety of CYTOKINE RECEPTORS such as ERYTHROPOIETIN RECEPTORS and INTERLEUKIN RECEPTORS. Dysregulation of Janus kinase 2 due to GENETIC TRANSLOCATIONS have been associated with a variety of MYELOPROLIFERATIVE DISORDERS.

Janus Kinase 3 [M0229568]
A Janus kinase subtype that is predominantly expressed in hematopoietic cell. It is involved in signaling from a broad variety of CYTOKINE RECEPTORS including ones that utilize the INTERLEUKIN RECEPTOR COMMON GAMMA SUBUNIT.

Jenacystein [M0447376]

JNK Mitogen-Activated Protein Kinases [M0362614]
A subgroup of mitogen-activated protein kinases that activate TRANSCRIPTION FACTOR AP-1 via the phosphorylation of C-JUN PROTEINS. They are components of intracellular signaling pathways that regulate CELL PROLIFERATION; APOPTOSIS; and CELL DIFFERENTIATION.

jun B Proteins [M0025513]

jun D Proteins [M0025514]

K-Casein [M0003593]

K-p NPPase [M0014912]

Kabikinase [M0020581]

Kabivitrum [M0020587]

Kallidin [M0011893]
A decapeptide bradykinin homolog cleaved from kininogen by kallikreins. It is a smooth-muscle stimulant and hypotensive agent that acts by vasodilatation.

Kallidin Tetraacetate [M0330195]

Kallidin, (D)-Isomer [M0330194]

Kallikrein A [M0011898]

Kallikrein B' [M0011899]

Kallikrein Light Chain [M0011902]

Kallikreins [M0011897]
Proteolytic enzymes from the serine endopeptidase family found in normal blood and urine. Specifically, Kallikreins are potent vasodilators and hypotensives and increase vascular permeability and affect smooth muscle. They act as infertility agents in men. Three forms are recognized, PLASMA KALLIKREIN (EC 3.4.21.34), TISSUE KALLIKREIN (EC 3.4.21.35), and PROSTATE-SPECIFIC ANTIGEN (EC 3.4.21.77).

Kalma Brand of Tryptophan [M0477041]

Kanamycin Kinase [M0029494]
A class of enzymes that inactivate aminocyclitol-aminoglycoside antibiotics (AMINOGLYCOSIDES) by regiospecific PHOSPHORYLATION of the 3' and/or 5' hydroxyl.

Kangai-1 Protein [M0220244]
A widely expressed transmembrane glycoprotein that functions as a METASTASIS suppressor protein. It is under-expressed in a variety of human NEOPLASMS.

kappa-Caseins [M0003594]

kappa-Elastin [M0007153]

kappa-Immunoglobulin Subgroup VK-12 [M0011137]

kappa-Immunoglobulin Subgroup VK-21 [M0011138]

Karyopherins [M0383377]
A family of proteins involved in NUCLEOCYTOPLASMIC TRANSPORT. Karyopherins are heteromeric molecules composed two major types of components, ALPHA KARYOPHERINS and BETA KARYOPHERINS, that function together to transport molecules through the NUCLEAR PORE COMPLEX. Several other proteins such as RAN GTP BINDING PROTEIN and CELLULAR APOPTOSIS SUSCEPTIBILITY PROTEIN bind to karyopherins and participate in the transport process.

Kassinin [M0023533]
Dodecapeptide tachykinin found in the central nervous system of the amphibian Kassina senegalensis. It is similar in structure and action to other tachykinins, but is especially effective in contracting smooth muscle tissue and stimulating the micturition reflex.

KCNQ Potassium Channels [M0481301]
A family of delayed rectifier voltage-gated potassium channels that share homology with their founding member, KCNQ1 PROTEIN. KCNQ potassium channels have been implicated in a variety of diseases including LONG QT SYNDROME; DEAFNESS; and EPILEPSY.

KCNQ1 Potassium Channel [M0267275]
A voltage-gated potassium channel that is expressed primarily in the HEART.

KCNQ2 Potassium Channel [M0285042]
A very slow opening and closing voltage-gated potassium channel that is expressed in NEURONS and is commonly mutated in BENIGN FAMILIAL NEONATAL CONVULSIONS.

KCNQ3 Potassium Channel [M0285045]
A very slow opening and closing voltage-gated potassium channel that is expressed in NEURONS and is closely related to KCNQ2 POTASSIUM CHANNEL. It is commonly mutated in BENIGN FAMILIAL NEONATAL CONVULSIONS.

Keratin, Glycosylated [M0143311]

Keratin-1 [M0494571]
A type II keratin that is found associated with the KERATIN-10 in terminally differentiated epidermal cells such as those that form the stratum corneum. Mutations in the genes that encode keratin-1 have been associated with HYPERKERATOSIS, EPIDERMOLYTIC.

Keratin-10 [M0204024]
A type I keratin that is found associated with the KERATIN-1 in terminally differentiated epidermal cells such as those that form the stratum corneum. Mutations in the genes that encode keratin-10 have been associated with HYPERKERATOSIS, EPIDERMOLYTIC.

Keratin-12 [M0449766]
A type I keratin that is found associated with the KERATIN-3 in the CORNEA and is regarded as a marker for corneal-type epithelial differentiation. Mutations in the gene for keratin-12 have been associated with MEESMANN CORNEAL EPITHELIAL DYSTROPHY.

Keratin-13 [M0011946]
A type I keratin that is found associated with the KERATIN-4 in the internal stratified EPITHELIUM. Defects in gene for keratin 13 cause HEREDITARY MUCOSAL LEUKOKERATOSIS.

Keratin-14 [M0284752]
A type I keratin that is found associated with the KERATIN-5 in the internal stratified EPITHELIUM. Mutations in the gene for keratin-14 are associated with EPIDERMOLYSIS BULLOSA SIMPLEX.

Keratin-15 [M0494730]
A type I keratin found in the basal layer of the adult epidermis and in other stratified epithelia.

Keratin-16 [M0011960]
A type I keratin expressed in a variety of EPITHELIUM, including the ESOPHAGUS, the TONGUE, the HAIR FOLLICLE and NAILS. Keratin-16 is normally found associated with KERATIN-6. Mutations in the gene for keratin-6 have been associated with PACHYONYCHIA CONGENITA, TYPE 1.

Keratin-17 [M0011961]
A type I keratin found associated with KERATIN-6 in rapidly proliferating squamous epithelial tissue. Mutations in gene for keratin-17 has been associated with PACHYONYCHIA CONGENITA, TYPE 2.

Keratin-18 [M0011947]
A type I keratin found associated with KERATIN-8 in simple, or predominately single layered, internal epithelia.

Keratin-19 [M0011948]
A type I keratin found associated with KERATIN-7 in ductal epithelia and gastrointestinal epithelia.

Keratin-2 [M0494572]
A type II keratin found expressed in the upper spinous layer of epidermal KERATINOCYTES. Mutations in genes that encode keratin-2A have been associated with ICHTHYOSIS BULLOSA OF SIEMENS.

Keratin-20 [M0220699]
A type I keratin expressed predominately in gastrointestinal epithelia, MERKEL CELLS, and the TASTE BUDS of the oral mucosa.

Keratin-2A [M0494620]

Keratin-2B [M0494621]

Keratin-3 [M0494573]
A type II keratin that is found associated with the KERATIN-12 in the CORNEA and is regarded as a marker for corneal-type epithelial differentiation. Mutations in the gene for keratin-3 have been associated with MEESMANN CORNEAL EPITHELIAL DYSTROPHY.

Keratin-4 [M0011949]
A type II keratin that is found associated with the KERATIN-13 in the internal stratified EPITHELIUM. Defects in gene for keratin-4 are a cause of HEREDITARY MUCOSAL LEUKOKERATOSIS.

Keratin-5 [M0494547]
A type II keratin that is found associated with the KERATIN-14 in the internal stratified EPITHELIUM. Mutations in the gene for keratin-5 are associated with EPIDERMOLYSIS BULLOSA SIMPLEX.

Keratin-6 [M0494509]
A type II keratin found associated with KERATIN-16 or KERATIN-17 in rapidly proliferating squamous epithelial tissue. Mutations in gene for keratin-6A and keratin-6B have been associated with PACHYONYCHIA CONGENITA, TYPE 1 and PACHYONYCHIA CONGENITA, TYPE 2 respectively.

Keratin-6A [M0494510]

Keratin-6B [M0494511]

Keratin-6E [M0494512]

Keratin-6F [M0494513]

Keratin-7 [M0287658]
A type II keratin found associated with KERATIN-19 in ductal epithelia and gastrointestinal epithelia.

Keratin-8 [M0011950]
A type II keratin found associated with KERATIN-18 in simple, or predominately single layered, internal epithelia.

Keratin-9 [M0011958]
A type II keratin found predominantly expressed in the terminally differentiated EPIDERMIS of palms and soles. Mutations in the gene for keratin 9 are associated with KERATODERMA, PALMOPLANTAR, EPIDERMOLYTIC.

Keratin-Associated Proteins [M0213667]

Keratins [M0011957]
A class of fibrous proteins or scleroproteins that represents the principal constituent of EPIDERMIS; HAIR; NAILS; horny tissues, and the organic matrix of tooth ENAMEL. Two major conformational groups have been characterized, alpha-keratin, whose peptide backbone forms a coiled-coil alpha helical structure consisting of TYPE I KERATIN and a TYPE II KERATIN, and beta-keratin, whose backbone forms a zigzag or pleated sheet structure. alpha-Keratins have been classified into at least 20 subtypes. In addition multiple isoforms of subtypes have been found which may be due to GENE DUPLICATION.

Keratins, Hair-Specific [M0494637]
Keratins that are specific for hard tissues such as HAIR; NAILS; and the filiform papillae of the TONGUE.

Keratins, Inner Root Sheath [M0494722]

Keratins, Type I [M0494332]
A keratin subtype that includes keratins that are generally smaller and more acidic that TYPE II KERATINS. Type I keratins combine with type II keratins to form keratin filaments.

Keratins, Type II [M0494335]
A keratin subtype that includes keratins that are generally larger and less acidic that TYPE I KERATINS. Type II keratins combine with type I keratins to form keratin filaments.

Ketoglutarate Dehydrogenase Complex [M0011989]

Ketol-Acid Reductoisomerase [M0076427]
An enzyme that catalyzes the oxidation of (R)-2,3-dihydroxy-3-methylbutanoate to (S)-2-hydroxy-2-methyl-3-oxobutanoate in the presence of NADP. It is involved in the biosynthesis of VALINE; LEUCINE; ISOLEUCINE; pentothenate and COENZYME A. This enzyme was formerly classified as EC 1.1.1.89.

Ketone Oxidoreductases [M0011994]
Oxidoreductases that are specific for KETONES.

Ki-67 Antigen [M0028859]
A CELL CYCLE and tumor growth marker which can be readily detected using IMMUNOCYTOCHEMISTRY methods. Ki-67 is a nuclear antigen present only in the nuclei of cycling cells.

Kidney Plasminogen Activator [M0022397]

Kidrolase [M0434511]

Kineret [M0475846]

Kinesin [M0025247]
A microtubule-associated mechanical adenosine triphosphatase, that uses the energy of ATP hydrolysis to move organelles along microtubules toward the plus end of the microtubule. The protein is found in squid axoplasm, optic lobes, and in bovine brain. Bovine kinesin is a heterotetramer composed of two heavy (120 kDa) and two light (62 kDa) chains. EC 3.6.1.-.

Kinevac [M0373218]

Kininogen [M0012052]

Kininogen, High-Molecular-Weight [M0029210]
A plasma protein, molecular weight of 110 kD, that normally exists in plasma in a 1:1 complex with PREKALLIKREIN. HMWK is split by plasma kallikrein to produce BRADYKININ. The complex is a cofactor in the activation of coagulation factor XII. The product of this reaction, XIIa, in turn activates prekallikrein to KALLIKREINS. (From Stedman, 26th ed)

Kininogen, Low-Molecular-Weight [M0029290]
A protein, molecular weight 50 kD, located in various normal tissues. Upon cleavage by KALLIKREINS, it forms KALLIDIN. Kallidin, in turn, is converted into BRADYKININ. (From Stedman, 25th ed)

Kininogens [M0012050]
Endogenous peptides present in most body fluids. Certain enzymes convert them to active KININS which are involved in inflammation, blood clotting, complement reactions, etc. Kininogens belong to the cystatin superfamily. They are cysteine proteinase inhibitors. HIGH-MOLECULAR-WEIGHT KININOGEN; (HMWK); is split by plasma kallikrein to produce BRADYKININ. LOW-MOLECULAR-WEIGHT KININOGEN; (LMWK); is split by tissue kallikrein to produce KALLIDIN.

Kinins [M0012054]
A generic term used to describe a group of polypeptides with related chemical structures and pharmacological properties that are widely distributed in nature. These peptides are AUTACOIDS that act locally to produce pain, vasodilatation, increased vascular permeability, and the synthesis of prostaglandins. Thus, they comprise a subset of the large number of mediators that contribute to the inflammatory response. (From Goodman and Gilman's The Pharmacologic Basis of Therapeutics, 8th ed, p588)

Kruppel-Like Transcription Factors [M0472513]
A family of zinc finger transcription factors that share homology with Kruppel protein, Drosophila. They contain a highly conserved seven amino acid spacer sequence in between their ZINC FINGER MOTIFS.

Kryptocur [M0012450]

Ku-Zyme [M0474888]

Kv Channel-Interacting Protein 1 [M0357803]

Kv Channel-Interacting Protein 2 [M0357805]

Kv Channel-Interacting Protein 3 [M0296271]

Kv Channel-Interacting Protein 4 [M0481150]

Kv Channel-Interacting Proteins [M0481140]
A family of neuronal calcium-sensor proteins that interact with and regulate potassium channels, type A.

Kv1.1 Potassium Channel [M0242712]
A delayed rectifier subtype of shaker potassium channels that is commonly mutated in human episodic ATAXIA and MYOKYMIA.

Kv1.1 Potassium Channel, Alpha Subunit [M0355043]

Kv1.1 Potassium Channel, Beta Subunit [M0332840]

Kv1.2 Potassium Channel [M0246842]
A delayed rectifier subtype of shaker potassium channels that is selectively inhibited by a variety of SCORPION VENOMS.

Kv1.2 Potassium Channel, Alpha Subunit [M0246840]

Kv1.2 Potassium Channel, Beta Subunit [M0246841]

Kv1.2' Channel [M0397543]

Kv1.3 Potassium Channel [M0238810]
A delayed rectifier subtype of shaker potassium channels that is the predominant VOLTAGE-GATED POTASSIUM CHANNEL of T-LYMPHOCYTES.

Kv1.4 Potassium Channel [M0248530]
A fast inactivating subtype of shaker potassium channels that contains two inactivation domains at its N terminus.

Kv1.5 Potassium Channel [M0244232]
A delayed rectifier subtype of shaker potassium channels that conducts a delayed rectifier current. It contributes to ACTION POTENTIAL repolarization of MYOCYTES in HEART ATRIA.

Kv1.6 Potassium Channel [M0236736]
A delayed rectifier subtype of shaker potassium channels that has been described in NEURONS and ASTROCYTES.

Kv2.1 Potassium Channel [M0236737]

Kv2.2 Potassium Channel [M0236738]

Kv3.1 Potassium Channel [M0259347]

Kv3.2 Potassium Channel [M0350061]

Kv4.1 Potassium Channel [M0362015]

Kv4.2 Potassium Channel [M0176531]

Kv4.3 Potassium Channel [M0267058]

Kv4.3L Potassium Channel [M0405454]

Kynurenine [M0012093]

Kynurenine 3-Monooxygenase [M0076440]
An NADPH-dependent flavin monooxygenase that plays a key role in the catabolism of TRYPTOPHAN by catalyzing the HYDROXYLATION of KYNURENINE to 3-hydroxykynurenine. It was formerly characterized as EC 1.14.1.2 and EC 1.99.1.5.

L-Amino Acid Oxidase [M0072365]
An enzyme that catalyzes the oxidative deamination of L-amino acids to KETO ACIDS with the generation of AMMONIA and HYDROGEN PEROXIDE. L-amino acid oxidase is widely distributed in and is thought to contribute to the toxicity of SNAKE VENOMS.

L-Aminoadipate-Semialdehyde Dehydrogenase [M0134338]
An enzyme that catalyzes the oxidation of L-2-aminoadipate 6-semialdehyde to L-2-aminoadipate (alpha-aminoadipic acid). It is involved in the biosynthetic pathway of LYSINE.

L-Gulonolactone Oxidase [M0075065]
An enzyme involved in the metabolism of ASCORBIC ACID and aldarate. It catalyzes the oxidation of L-gulono-1,4-lactone to L-xylo-hex-3-ulonolactone.

L-Iditol 2-Dehydrogenase [M0010988]
An alcohol oxidoreductase which catalyzes the oxidation of L-iditol to L-sorbose in the presence of NAD. It also acts on D-glucitol to form D-fructose. It also acts on other closely related sugar alcohols to form the corresponding sugar. EC 1.1.1.14

L-isomer of Homoserine [M0330254]

L-Lactate Dehydrogenase [M0012145]
A tetrameric enzyme that, along with the coenzyme NAD+, catalyzes the interconversion of LACTATE and PYRUVATE. In vertebrates, genes for three different subunits (LDH-A, LDH-B and LDH-C) exist.

L-Lactate Dehydrogenase (Cytochrome) [M0076470]
A cytochrome form of lactate dehydrogenase found in the MITOCHONDRIA. It catalyzes the oxidation of L-lactate to PYRUVATE with transfer of electrons to CYTOCHROME C. The enzyme utilizes FMN and PROTOHEME IX as cofactors.

L-Lysine 6-Transaminase [M0076570]
A PYRIDOXAL PHOSPHATE containing enzyme that catalyzes the transfer of amino group of L-LYSINE onto 2-OXOGLUTARATE to generate 2-aminoadipate 6-semialdehyde and L-GLUTAMATE.

L-MAG [M0028365]

L-myc Proteins [M0024865]

L-Selectin [M0028430]
Cell adhesion molecule and CD antigen that serves as a homing receptor for lymphocytes to lymph node high endothelial venules.

L-Serine Dehydratase [M0019676]
A PYRIDOXAL-phosphate containing enzyme that catalyzes the dehydration and deamination of L-serine to form pyruvate. This enzyme was formerly listed as EC 4.2.1.13.

L-Thyrox [M0463506]

L-Thyroxin beta [M0463503]

L-Thyroxin Henning [M0463504]

L-Thyroxine Roche [M0463505]

L-Tryptophan-ratiopharm [M0477042]

L-Type VDCC alpha-2 Subunit [M0337686]

L-Type VDCC beta Subunit [M0333269]

L-Type VDCC delta Subunit [M0333270]

L-Type VDCC gamma Subunit [M0333271]

L3T4 Antigens [M0001416]

Lac Repressors [M0018808]

Laccase [M0083360]
A copper-containing oxidoreductase enzyme that catalyzes the oxidation of 4-benzenediol to 4-benzosemiquinone. It also has activity towards a variety of O-quinols and P-quinols. It primarily found in FUNGI and is involved in LIGNIN degradation, pigment biosynthesis and detoxification of lignin-derived products.

Laccase B [M0447101]

Laccase I [M0447103]

Laccase II [M0447104]

Laccase III [M0447105]

LaCrosse Virus Envelope Glycoprotein G1 [M0022713]

Lactaid [M0372302]

Lactalbumin [M0012142]

Lactase [M0180448]
An enzyme which catalyzes the hydrolysis of LACTOSE to D-GALACTOSE and D-GLUCOSE. Defects in the enzyme cause LACTOSE INTOLERANCE.

Lactase-Phlorizin Hydrolase [M0016614]

Lactate Dehydrogenases [M0447007]
Alcohol oxidoreductases with substrate specificity for LACTIC ACID.

Lactate Transport Proteins [M0110483]

Lactoferrin [M0012165]
An iron-binding protein in plasma and secretions (milk, mucus, bile), secreted by leukocytes. It is an important component of GRANULOCYTES. It is bacteriostatic, working by depriving bacteria of iron essential for growth.

Lactogest [M0477143]

Lactoglobulins [M0012174]
Globulins occurring in milk. (From Dorland, 28th ed)

Lactoperoxidase [M0012176]
An enzyme derived from cow's milk. It catalyzes the radioiodination of tyrosine and its derivatives and of peptides containing tyrosine.

Lactose Synthase [M0012181]
An enzyme of the transferase class that catalyzes the transfer of galactose from UDPgalactose to glucose, forming lactose. The enzyme is a complex of the enzyme N-ACETYLLACTOSAMINE SYNTHASE and alpha-lactalbumin; the latter protein is present in lactating mammary gland cells where it alters the usual specificity of the former to make lactose synthesis the preferred reaction. (Dorland, 28th ed) EC 2.4.1.22.

Lactoylglutathione Lyase [M0012185]
An enzyme that catalyzes the interconversion of methylglyoxal and lactate, with glutathione serving as a coenzyme. EC 4.4.1.5.

Lactrase [M0477144]

lambda-1-Immunoglobulin [M0011140]

lambda-2-Immunoglobulin [M0011141]

lambda-x Immunoglobulin [M0011142]

Lamin Type A [M0089366]
A subclass of developmentally regulated lamins having a neutral isoelectric point. They are found to disassociate from nuclear membranes during mitosis.

Lamin Type B [M0089367]
A subclass of ubiquitously-expressed lamins having an acidic isoelectric point. They are found to remain bound to nuclear membranes during mitosis.

Laminarinase [M0445570]

Laminin [M0012194]
Large, noncollagenous glycoprotein with antigenic properties. It is localized in the basement membrane lamina lucida and functions to bind epithelial cells to the basement membrane. Evidence suggests that the protein plays a role in tumor invasion.

Laminin M [M0012195]

Laminin M Chain [M0012196]

Lamins [M0089372]
Nuclear matrix proteins that are structural components of the NUCLEAR LAMINA. They are found in most multicellular organisms.

Lantamed [M0447377]

Lantibiotics [M0478850]
Class I bacteriocins. They are produced by bacteria that live on LACTIC ACID and contain the sulfur-containing lanthionine amino acid.

Large Neutral Amino Acid-Transporter 1 [M0151515]
A CD98 antigen light chain that when heterodimerized with CD98 antigen heavy chain (ANTIGENS, CD98 HEAVY CHAIN) forms a protein that mediates sodium-independent L-type amino acid transport.

Large-Conductance Calcium-Activated Potassium Channel alpha Subunits [M0479027]
The pore-forming subunits of large-conductance calcium-activated potassium channels. They form tetramers in CELL MEMBRANES.

Large-Conductance Calcium-Activated Potassium Channel beta Subunits [M0479028]
The regulatory subunits of large-conductance calcium-activated potassium channels.

Large-Conductance Calcium-Activated Potassium Channels [M0218785]
A major class of calcium activated potassium channels whose members are voltage-dependent. MaxiK channels are activated by either membrane depolarization or an increase in intracellular Ca(2+). They are key regulators of calcium and electrical signaling in a variety of tissues.

Larodopa [M0012435]

Latent TGF-beta Binding Protein 1 [M0496434]

Latent TGF-beta Binding Protein 2 [M0496435]

Latent TGF-beta Binding Protein 3 [M0496436]

Latent TGF-beta Binding Protein 4 [M0496437]

Latent TGF-beta Binding Proteins [M0472419]
A family of secreted multidomain proteins that were originally identified by their association with the latent form of TRANSFORMING GROWTH FACTORS. They interact with a variety of EXTRACELLULAR MATRIX PROTEINS and may play a role in the regulation of TGB-beta bioavailability.

LDL-1 [M0012588]
Low-density lipoprotein particles with density between 1.019 and 1.045 g/ml.

LDL-2 [M0012589]
Low-density lipoprotein particles with density between 1.045 and 1.063 g/ml.

LDL-Receptor Related Protein 1 [M0378357]
A LDL-receptor related protein involved in clearance of chylomicron remnants and of activated ALPHA-MACROGLOBULINS from plasma.

LDL-Receptor Related Protein 2 [M0112822]
An LDL-RECEPTOR RELATED PROTEIN found in the neuroepithelium and in proximal tubular cells of the kidney. It is considered a multiligand receptor in that it binds to a variety of ligands with relatively high affinity and may function in mediating the uptake and lysosomal degradation of macromolecules such as: LIPOPROTEINS; ENDOPEPTIDASES; and PROTEASE INHIBITORS.

LDL-Receptor Related Protein-Associated Protein [M0094820]
A membrane protein found in the rough endoplasm reticulum (ENDOPLASMIC RETICULUM, ROUGH) that binds to LDL-RECEPTOR RELATED PROTEINS. It may function to prevent ligand binding of receptors during protein processing events within endosomal compartments.

LDL-Receptor Related Proteins [M0378356]
A family of proteins that share sequence similarity with the low density lipoprotein receptor (RECEPTORS, LDL).

Leader Signal Peptides [M0358903]

Lebic [M0454549]

Lectins [M0412029]
Proteins that share the common characteristic of binding to carbohydrates. Some ANTIBODIES and carbohydrate-metabolizing proteins (ENZYMES) also bind to carbohydrates, however they are not considered lectins. PLANT LECTINS are carbohydrate-binding proteins that have been primarily identified by their hemagglutinating activity (HEMAGGLUTININS). However, a variety of lectins occur in animal species where they serve diverse array of functions through specific carbohydrate recognition.

Lectins, C-Type [M0278169]
A class of animal lectins that bind to carbohydrate in a calcium-dependent manner. They share a common carbohydrate-binding domain that is structurally distinct from other classes of lectins.

Leftose [M0014213]

Leghemoglobin [M0012289]
A hemoglobin-like oxygen-binding hemeprotein present in the nitrogen-fixing root nodules of leguminous plants. The red pigment has a molecular weight approximately 1/4 that of hemoglobin and has been suggested to act as an oxido-reduction catalyst in symbiotic nitrogen fixation.

Leghemoglobin A [M0012290]

Leptin [M0328567]
A 16-kDa peptide hormone secreted from white adipocytes and implicated in the regulation of food intake and energy balance. Leptin provides the key afferent signal from fat cells in the feedback system that controls body fat stores.

Leu-11 Antigens [M0026483]

Leucine [M0012372]
An essential branched-chain amino acid important for hemoglobin formation.

Leucine Dehydrogenase [M0076542]
An octameric enzyme belonging to the superfamily of amino acid dehydrogenases. Leucine dehydrogenase catalyzes the reversible oxidative deamination of L-LEUCINE, to 4-methyl-2-oxopentanoate (2-ketoisocaproate) and AMMONIA, with the corresponding reduction of the cofactor NAD+.

Leucine Transaminase [M0076540]
A PYRIDOXAL PHOSPHATE containing enzyme that catalyzes the reversible transamination of branched-chain AMINO ACIDS to 2-OXOGLUTARATE.

Leucine-Responsive Regulatory Protein [M0188803]
A LEUCINE and DNA-binding protein that is found primarily in BACTERIA and ARCHAEA. It regulates GENETIC TRANSCRIPTION involved in METABOLISM of AMINO ACIDS in response to the increased concentration of LEUCINE.

Leucine-tRNA Ligase [M0012378]
An enzyme that activates leucine with its specific transfer RNA. EC 6.1.1.4.

Leucyl Aminopeptidase [M0012373]
A zinc containing enzyme of the hydrolase class that catalyzes the removal of the N-terminal amino acid from most L-peptides, particularly those with N-terminal leucine residues but not those with N-terminal lysine or arginine residues. This occurs in tissue cell cytosol, with high activity in the duodenum, liver, and kidney. EC 3.4.11.1

Leucyl-beta-Naphthylamidase [M0012379]
An aminopeptidase frequently used to test for LEUCYL AMINOPEPTIDASE activity. It also hydrolyzes naphthylamides of leucine. EC 3.4.11.-.

Leukemia Inhibitory Factor [M0097307]
An INTERLEUKIN-6 related cytokine that exhibits pleiotrophic effects on many physiological systems that involve cell proliferation, differentiation, and survival. Leukemia inhibitory factor binds to and acts through the LIF RECEPTOR.

Leukemia Inhibitory Factor Receptor alpha Subunit [M0495573]
A receptor subunit that combines with CYTOKINE RECEPTOR GP130 to form the dual specificity receptor for LEUKEMIA INHIBITORY FACTOR and ONCOSTATIN M. The subunit is also a component of the CILIARY NEUROTROPHIC FACTOR RECEPTOR. Both membrane-bound and secreted isoforms of the receptor subunit exist due to ALTERNATIVE SPLICING of its mRNA. The secreted isoform is believed to act as an inhibitory receptor, while the membrane-bound form is a signaling receptor.

Leukemia Lymphoma Virus Antibodies, Human T Cell [M0023841]

Leukemia Lymphoma Virus Antigens, Human T Cell [M0023848]

Leukemia Virus Antibodies, Human T-Cell [M0023840]

Leukemia Virus Antigens, Human T-Cell [M0023847]

Leukocidin [M0012401]

Leukocidins [M0012402]
Pore forming proteins originally discovered for toxic activity to LEUKOCYTES. They are EXOTOXINS produced by some pathogenic STAPHYLOCOCCUS and STREPTOCOCCUS that destroy leukocytes by lysis of the cytoplasmic granules and are partially responsible for the pathogenicity of the organisms.

Leukocyte Adhesion Molecules [M0024224]

Leukocyte Elastase [M0028701]
An enzyme that catalyzes the hydrolysis of proteins, including elastin. It cleaves preferentially bonds at the carboxyl side of Ala and Val, with greater specificity for Ala. EC 3.4.21.37.

Leukocyte L1 Antigen Complex [M0122495]
A member of the S-100 protein family that is present at high levels in the blood and interstitial fluid in several infectious, inflammatory, and malignant disorders, including rheumatoid arthritis, inflammatory bowel disease, and cystic fibrosis. It is a complex of a light chain (CALGRANULIN A) and a heavy chain (CALGRANULIN B). L1 binds calcium through an EF-hand motif, and has been shown to possess antimicrobial activity.

Leukocyte Migration-Inhibitory Factors [M0012410]
Protein factor(s) released by sensitized lymphocytes (and possibly other cells) that inhibit the movement of leukocytes, especially polymorphonuclear cells, away from their site of release. Assays for these factors are used as tests for cellular immunity. Two of the common assays are the leukocyte migration capillary tube technique (LMCT) and the leukocyte migration agarose technique (LMAT).

Leukovirus Proteins [M0018983]

Leupeptins [M0012428]
A group of acylated oligopeptides produced by Actinomycetes that function as protease inhibitors. They have been known to inhibit to varying degrees trypsin, plasmin, KALLIKREINS, papain and the cathepsins.

Leuprolide [M0025473]
A potent synthetic long-acting agonist of GONADOTROPIN-RELEASING HORMONE that regulates the synthesis and release of pituitary gonadotropins, LUTEINIZING HORMONE and FOLLICLE STIMULATING HORMONE.

Leuprolide Acetate [M0329431]

Leuprolide Monoacetate [M0329430]

Leuprolide, (DL-Leu)-Isomer [M0329429]

Leuprolide, (L-Leu)-Isomer [M0329428]

Levo-T [M0463507]

Levodopa [M0012434]
The naturally occurring form of DIHYDROXYPHENYLALANINE and the immediate precursor of DOPAMINE. Unlike dopamine itself, it can be taken orally and crosses the blood-brain barrier. It is rapidly taken up by dopaminergic neurons and converted to DOPAMINE. It is used for the treatment of PARKINSONIAN DISORDERS and is usually given with agents that inhibit its conversion to dopamine outside of the central nervous system.

Levopa [M0351195]

Levothroid [M0463508]

Levothyroid [M0373368]

L�vothyrox [M0463512]

Levothyroxin Deladande [M0463509]

Levothyroxine Sodium [M0373450]

Levoxine [M0373451]

Levoxyl [M0378850]

Levulan [M0455973]

Ligases [M0012509]
A class of enzymes that catalyze the formation of a bond between two substrate molecules, coupled with the hydrolysis of a pyrophosphate bond in ATP or a similar energy donor. (Dorland, 28th ed) EC 6.

Light Meromyosin [M0024313]

Light-Harvesting Bacteriochlorophyll Protein Complexes [M0024727]

Light-Harvesting Chlorophyll Protein [M0024720]

Light-Harvesting Protein Complexes [M0447900]
Complexes containing CHLOROPHYLL and other photosensitive molecules. They serve to capture energy in the form of PHOTONS are generally found as components of the PHOTOSYSTEM I PROTEIN COMPLEX or the PHOTOSYSTEM II PROTEIN COMPLEX.

Lindocetyl [M0447379]

Linear Gramicidin [M0009597]

Linoleoyl-CoA Desaturase [M0094404]
An enzyme that catalyzes the syn-dehydrogenation of linoleol-CoA gamma-linolenoyl-CoA. It was formerly characterized as EC 1.14.99.25.

Lioresal [M0002118]

Lipase [M0012545]
An enzyme of the hydrolase class that catalyzes the reaction of triacylglycerol and water to yield diacylglycerol and a fatty acid anion. It is produced by glands on the tongue and by the pancreas and initiates the digestion of dietary fats. (From Dorland, 27th ed) EC 3.1.1.3.

Lipoprotein (a-) [M0026213]
Lipoprotein(a) with the antiangiogenic APOLIPOPROTEIN (A) removed.

Lipoprotein Lipase [M0012578]
An enzyme of the hydrolase class that catalyzes the reaction of triacylglycerol and water to yield diacylglycerol and a fatty acid anion. The enzyme hydrolyzes triacylglycerols in chylomicrons, very-low-density lipoproteins, low-density lipoproteins, and diacylglycerols. It occurs on capillary endothelial surfaces, especially in mammary, muscle, and adipose tissue. Genetic deficiency of the enzyme causes familial hyperlipoproteinemia Type I. (Dorland, 27th ed) EC 3.1.1.34.

Lipoprotein(a) [M0026212]
A lipoprotein that resembles the LOW-DENSITY LIPOPROTEINS but with an extra protein moiety, APOPROTEIN (A) also known as APOLIPOPROTEIN (A), linked to APOLIPOPROTEIN B-100 on the LDL by one or two disulfide bonds. High plasma level of lipoprotein (a) is associated with increased risk of atherosclerotic cardiovascular disease.

Lipoprotein-X [M0012580]
An abnormal lipoprotein present in large amounts in patients with obstructive liver diseases such as INTRAHEPATIC CHOLESTASIS. LP-X derives from the reflux of BILE lipoproteins into the bloodstream. LP-X is a low-density lipoprotein rich in free CHOLESTEROL and PHOSPHOLIPIDS but poor in TRIGLYCERIDES; CHOLESTEROL ESTERS; and protein.

Lipoproteins [M0012581]
Lipid-protein complexes involved in the transportation and metabolism of lipids in the body. They are spherical particles consisting of a hydrophobic core of TRIGLYCERIDES and CHOLESTEROL ESTERS surrounded by a layer of hydrophilic free CHOLESTEROL; PHOSPHOLIPIDS; and APOLIPOPROTEINS. Lipoproteins are classified by their varying buoyant density and sizes. The large lipoproteins (CHYLOMICRONS; VLDL) are to transport triglycerides, and the small lipoproteins (LDL; HDL) are to transport cholesterol.

Lipoproteins, HDL [M0012584]
A class of lipoproteins of small size (4-13 nm) and dense (greater than 1.063 g/ml) particles. HDL lipoproteins, synthesized in the liver without a lipid core, accumulate cholesterol esters from peripheral tissues and transport them to the liver for re-utilization or elimination from the body (the reverse cholesterol transport). Their major protein component is APOLIPOPROTEIN A-I. HDL also shuttle APOLIPOPROTEINS C and APOLIPOPROTEINS E to and from triglyceride-rich lipoproteins during their catabolism. HDL plasma level has been inversely correlated with the risk of cardiovascular diseases.

Lipoproteins, HDL2 [M0083309]
Low-density subclass of the high-density lipoproteins, with particle sizes between 8 to 13 nm.

Lipoproteins, HDL3 [M0012583]
Intermediate-density subclass of the high-density lipoproteins, with particle sizes between 7 to 8 nm. As the larger lighter HDL2 lipoprotein, HDL3 lipoprotein is lipid-rich.

Lipoproteins, IDL [M0012594]
A mixture of very-low-density lipoproteins (VLDL), particularly the triglyceride-poor VLDL, with slow diffuse electrophoretic mobilities in the beta and alpha2 regions which are similar to that of beta-lipoproteins (LDL) or alpha-lipoproteins (HDL). They can be intermediate (remnant) lipoproteins in the de-lipidation process, or remnants of mutant CHYLOMICRONS and VERY-LOW-DENSITY LIPOPROTEINS which cannot be metabolized completely as seen in FAMILIAL DYSBETALIPOPROTEINEMIA.

Lipoproteins, LDL [M0012590]
A class of lipoproteins of small size (18-25 nm) and light (1.019-1.063 g/ml) particles with a core composed mainly of CHOLESTEROL ESTERS and smaller amounts of TRIGLYCERIDES. The surface monolayer consists mostly of PHOSPHOLIPIDS, a single copy of APOLIPOPROTEIN B-100, and free cholesterol molecules. The main LDL function is to transport cholesterol and cholesterol esters to extrahepatic tissues.

Lipoproteins, VLDL [M0012596]
A class of lipoproteins of very light (0.93-1.006 g/ml) large size (30-80 nm) particles with a core composed mainly of TRIGLYCERIDES and a surface monolayer of PHOSPHOLIPIDS and CHOLESTEROL into which are imbedded the apolipoproteins B, E, and C. VLDL facilitates the transport of endogenously made triglycerides to extrahepatic tissues. As triglycerides and Apo C are removed, VLDL is converted to INTERMEDIATE-DENSITY LIPOPROTEINS, then to LOW-DENSITY LIPOPROTEINS from which cholesterol is delivered to the extrahepatic tissues.

Lipoproteins, VLDL1 [M0492982]
Low density large VLDL particles (60-100 nm).

Lipoproteins, VLDL2 [M0012595]
Intermediate density and size VLDL particles (40-60 nm).

Lipoproteins, VLDL3 [M0492983]
High density small VLDL particles (30-40 nm).

Lipoxygenase [M0012610]
An enzyme of the oxidoreductase class that catalyzes reactions between linoleate and other fatty acids and oxygen to form hydroperoxy-fatty acid derivatives. Related enzymes in this class include the ARACHIDONATE LIPOXYGENASES; ARACHIDONATE 5-LIPOXYGENASE; ARACHIDONATE 12-LIPOXYGENASE; and ARACHIDONATE 15-LIPOXYGENASE. EC 1.13.11.12.

Lipoxygenase-1 [M0012608]

Lipoxygenase-2 [M0012609]

Lipram [M0474889]

Liquimeth [M0369444]

Lisinopril [M0026771]
One of the ANGIOTENSIN-CONVERTING ENZYME INHIBITORS (ACE inhibitors), orally active, that has been used in the treatment of hypertension and congestive heart failure.

Lisinopril Maleate (1:1) [M0329233]

Lisinopril Sulfate (1:2) [M0329232]

Lithostathine [M0109980]
The proteinaceous component of the pancreatic stone in patients with PANCREATITIS.

Liver Cell Adhesion Molecule [M0494935]

Liver-Derived Lymphocyte Proliferation Inhibiting Protein [M0001682]

Liver-Enriched Inhibiting Protein [M0251195]
A truncated form of CCAAT-ENHANCER-BINDING PROTEIN-BETA that acts as a translational repressor.

Lixacol [M0474827]

LL-D05139a [M0373517]

Long Chain Base Biosynthesis Protein 1 [M0479324]

Long Chain Base Biosynthesis Protein 2 [M0479323]

Long-Acting Thyroid Stimulator [M0012687]
An immunoglobulin G, often found in the blood of hyperthyroid individuals. It stimulates the thyroid for a longer duration than does thyrotoxin and may cause hyperthyroidism in newborns due to placental transmission.

Lopirin [M0338109]

LPA1 Receptor [M0451109]

LPA2 Receptor [M0203728]

LPA3 Receptor [M0336910]

Luciferases [M0012720]
Enzymes that oxidize certain LUMINESCENT AGENTS to emit light (PHYSICAL LUMINESCENCE). The luciferases from different organisms have evolved differently so have different structures and substrates.

Luciferases, Bacterial [M0464574]
Luciferases from BACTERIA such as PHOTOBACTERIUM; VIBRIO; and PHOTORHABDUS.

Luciferases, Firefly [M0464338]
Luciferases from FIREFLIES, usually Photinus, that oxidizes FIREFLY LUCIFERIN to cause emission of PHOTONS.

Luciferases, Photobacterium [M0464575]

Luciferases, Photorhabdus [M0464577]

Luciferases, Renilla [M0464339]
Luciferases from RENILLA that oxidizes certain LUMINESCENT AGENTS to cause emission of PHOTONS.

Luciferases, Vibrio [M0464576]

Luminescent Proteins [M0012736]
Proteins which are involved in the phenomenon of light emission in living systems. Included are the "enzymatic" and "non-enzymatic" types of system with or without the presence of oxygen or co-factors.

Lundbeck Brand of Bleomycin Sulfate [M0472986]

Lupron [M0369306]

Lupus Coagulation Inhibitor [M0025416]
An antiphospholipid antibody found in association with systemic lupus erythematosus (LUPUS ERYTHEMATOSUS, SYSTEMIC;), ANTIPHOSPHOLIPID SYNDROME; and in a variety of other diseases as well as in healthy individuals. In vitro, the antibody interferes with the conversion of prothrombin to thrombin and prolongs the partial thromboplastin time. In vivo, it exerts a procoagulant effect resulting in thrombosis mainly in the larger veins and arteries. It further causes obstetrical complications, including fetal death and spontaneous abortion, as well as a variety of hematologic and neurologic complications.

Luteinizing Hormone [M0012444]
A major gonadotropin secreted by the adenohypophysis (PITUITARY GLAND, ANTERIOR). Luteinizing hormone regulates steroid production by the interstitial cells of the TESTIS and the OVARY. The preovulatory LUTEINIZING HORMONE surge in females induces OVULATION, and subsequent LUTEINIZATION of the follicle. LUTEINIZING HORMONE consists of two noncovalently linked subunits, alpha and beta. Within a species, the alpha subunit is common in the three pituitary glycoprotein hormones (TSH, LH and FSH), but the beta subunit is unique and confers its biological specificity.

Luteinizing Hormone, beta Subunit [M0115487]
The beta subunit of luteinizing hormone. It is a 15-kDa glycopolypeptide with structure similar to the beta subunit of the placental chorionic gonadatropin (CHORIONIC GONADOTROPIN, BETA SUBUNIT, HUMAN) except for the additional 31 amino acids at the C-terminal of CG-beta. Full biological activity of LH requires the non-covalently bound heterodimers of an alpha and a beta subunit. Mutation of the LHB gene causes HYPOGONADISM and infertility.

Luteozyman [M0012445]

LY-146032 [M0373922]

Lyases [M0012769]
A class of enzymes that catalyze the cleavage of C-C, C-O, and C-N, and other bonds by other means than by hydrolysis or oxidation. (Enzyme Nomenclature, 1992) EC 4.

Lymphocyte Antigen 96 [M0306619]
A secreted protein that associates with TOLL-LIKE RECEPTOR 4 and is essential for receptor recognition of LIPOPOLYSACCHARIDES.

Lymphocyte Function-Associated Antigen-1 [M0024683]
An integrin heterodimer widely expressed on cells of hematopoietic origin. CD11A ANTIGEN comprises the alpha chain and the CD18 antigen (ANTIGENS, CD18) the beta chain. Lymphocyte function-associated antigen-1 is a major receptor of T-CELLS; B-CELLS; and GRANULOCYTES. It mediates the leukocyte adhesion reactions underlying cytolytic conjugate formation, helper T-cell interactions, and antibody-dependent killing by NATURAL KILLER CELLS and granulocytes. Intracellular adhesion molecule-1 has been defined as a ligand for lymphocyte function-associated antigen-1.

Lymphocyte Immune Globulin, Anti-Thymocyte Globulin (Equine) [M0454797]

Lymphocyte Specific Protein Tyrosine Kinase p56(lck) [M0029483]
This enzyme is a lymphoid-specific src family tyrosine kinase that is critical for T-cell development and activation. Lck is associated with the cytoplasmic domains of CD4, CD8 and the beta-chain of the IL-2 receptor, and is thought to be involved in the earliest steps of TCR-mediated T-cell activation.

Lymphocytotoxic Antibodies [M0001467]

Lymphoid Enhancer-Binding Factor 1 [M0188043]
A T-cell factor that plays an essential role in EMBRYONIC DEVELOPMENT.

Lymphokines [M0012816]
Soluble protein factors generated by activated lymphocytes that affect other cells, primarily those involved in cellular immunity.

Lymphotoxin alpha1, beta2 Heterotrimer [M0492829]
A heterotrimer complex consisting of one molecule of LYMPHOTOXIN-ALPHA and two molecules of the LYMPHOTOXIN-BETA. It is anchored to the cell surface via the transmembrane domains of the lymphotoxin-beta component and has specificity for the LYMPHOTOXIN BETA RECEPTOR. The lymphotoxin alpha1, beta2 heterotrimer plays a role in regulating lymphoid ORGANOGENESIS and the differentiation of certain subsets of NATURAL KILLER CELLS.

Lymphotoxin beta Receptor [M0230458]
A member of the tumor necrosis factor receptor superfamily. It has specificity for LYMPHOTOXIN ALPHA1, BETA2 HETEROTRIMER and TUMOR NECROSIS FACTOR LIGAND SUPERFAMILY MEMBER 14. The receptor plays a role in regulating lymphoid ORGANOGENESIS and the differentiation of certain subsets of NATURAL KILLER-T CELLS. Signaling of the receptor occurs through its association with TNF RECEPTOR-ASSOCIATED FACTORS.

Lymphotoxin-alpha [M0012828]
A tumor necrosis factor family member that is released by activated LYMPHOCYTES. Soluble lymphotoxin is specific for TUMOR NECROSIS FACTOR RECEPTOR TYPE I; TUMOR NECROSIS FACTOR RECEPTOR TYPE II; and TUMOR NECROSIS FACTOR RECEPTOR SUPERFAMILY, MEMBER 14. Lymphotoxin-alpha can form a membrane-bound heterodimer with LYMPHOTOXIN-BETA that has specificity for the LYMPHOTOXIN BETA RECEPTOR.

Lymphotoxin-alpha3 [M0276797]

Lymphotoxin-beta [M0240454]
A membrane-bound tumor necrosis family member found primarily on LYMPHOCYTES. It can form a heterotrimer (LYMPHOTOXIN ALPHA1, BETA2 HETEROTRIMER) with the soluble ligand LYMPHOTOXIN-ALPHA and anchor it to the cell surface. The membrane-bound complex is specific for the LYMPHOTOXIN BETA receptor.

Lyphan [M0477043]

Lysine [M0012835]
An essential amino acid. It is often added to animal feed.

Lysine Acetate [M0330097]

Lysine Carboxypeptidase [M0001685]
A metallocarboxypeptidase that removes C-terminal basic amino acid from peptides and proteins, with preference shown for lysine over arginine. It is a plasma zinc enzyme that inactivates bradykinin and anaphylatoxins.

Lysine Hydrochloride [M0330098]

Lysine Vasopressin [M0012831]
The porcine antidiuretic hormone (VASOPRESSINS). It is a cyclic nonapeptide that differs from ARG-VASOPRESSIN by one amino acid, containing an LYSINE at residue 8 instead of an ARGININE. Lys-vasopressin is used to treat DIABETES INSIPIDUS or to improve vasomotor tone and BLOOD PRESSURE.

Lysine-tRNA Ligase [M0012852]
An enzyme that activates lysine with its specific transfer RNA. EC 6.1.1.6.

Lysinoalanine [M0012839]
N(6)-(2-Amino-2-carboxyethyl)-L-lysine. An unusual amino acid, not a dipeptide, which has been found in proteins of cooked foods. It is formed in food that is heated or treated with alkali. Has been implicated in nephrocytomegalia in rats.

Lysophospholipase [M0012843]
An enzyme that catalyzes the hydrolysis of a single fatty acid ester bond in lysoglycerophosphatidates with the formation of glyceryl phosphatidates and a fatty acid. EC 3.1.1.5.

Lysophospholipase A [M0012844]

Lysophospholipase A1 [M0012845]

Lysophospholipase C [M0012846]

Lysophospholipase L2 [M0012847]

Lysosomal alpha-Glucosidase [M0497620]

Lysosomal alpha-Mannosidase [M0446508]

Lysosomal Integral Membrane Proteins [M0482080]

Lysosomal Membrane Glycoproteins [M0482081]

Lysosomal-Associated Membrane Protein 1 [M0142865]
An abundant lysosomal-associated membrane protein that has been found to shuttle between LYSOSOMES; ENDOSOMES; and the PLASMA MEMBRANE. In PLATELETS and T-LYMPHOCYTES it may play a role in the cellular degranulation process.

Lysosomal-Associated Membrane Protein 2 [M0142866]
An abundant lysosomal-associated membrane protein that has been found to shuttle between LYSOSOMES; ENDOSOMES; and the PLASMA MEMBRANE. Loss of expression of lysosomal-associated membrane protein 2 is associated with GLYCOGEN STORAGE DISEASE TYPE IIB.

Lysosomal-Associated Membrane Protein 3 [M0142867]

Lysosomal-Associated Membrane Proteins [M0482079]

Lysosome-Associated Membrane Glycoproteins [M0142877]
Ubiquitously expressed integral membrane glycoproteins found in the LYSOSOME.

Lysostaphin [M0012850]
A 25-kDa peptidase produced by Staphylococcus simulans which cleaves a glycine-glcyine bond unique to an inter-peptide cross-bridge of the STAPHYLOCOCCUS AUREUS cell wall. EC 3.4.24.75.

M beta-Acrosin [M0000266]

M-Pectil [M0447395]

M-Type Pyruvate Kinase [M0018295]

M1-Type Pyruvate Kinase [M0018296]

M2-Type Pyruvate Kinase [M0018297]

Macro-Creatine Kinase [M0483994]

Macroglobulins [M0012866]
Serum globulins with high molecular weight. (Dorland, 28th ed)

Macrophage Colony-Stimulating Factor [M0024689]
A mononuclear phagocyte colony-stimulating factor (M-CSF) synthesized by mesenchymal cells. The compound stimulates the survival, proliferation, and differentiation of hematopoietic cells of the monocyte-macrophage series. M-CSF is a disulfide-bonded glycoprotein dimer with a MW of 70 kDa. It binds to a specific high affinity receptor (RECEPTOR, MACROPHAGE COLONY-STIMULATING FACTOR).

Macrophage Inflammatory Protein-1 [M0028874]
A chemokine that is chemotactic for neutrophils and monocytes, stimulates macrophages, and may play a role in regulating hematopoiesis. Its two variants, MIP-1alpha and MIP-1beta, are 60% homologous to each other.

Macrophage Inflammatory Proteins [M0028870]
Heparin-binding proteins that exhibit a number of inflammatory and immunoregulatory activities. Originally identified as secretory products of macrophages, these chemokines are produced by a variety of cell types including neutrophils, fibroblasts, and epithelial cells. They likely play a significant role in respiratory tract defenses.

Macrophage Migration-Inhibitory Factors [M0012870]
Proteins released by sensitized lymphocytes and possibly other cells that inhibit the migration of macrophages away from the release site. The structure and chemical properties may vary with the species and type of releasing cell.

Macrophage-1 Antigen [M0024694]
An adhesion-promoting leukocyte surface membrane heterodimer. The alpha subunit consists of the CD11b ANTIGEN and the beta subunit the CD18 ANTIGEN. The antigen, which is an integrin, functions both as a receptor for complement 3 and in cell-cell and cell-substrate adhesive interactions.

Macrophage-Granulocyte Inducer [M0004823]

MADS Domain Proteins [M0238874]
A superfamily of proteins that share a highly conserved MADS domain sequence motif. The term MADS refers to the first four members which were MCM1 PROTEIN; AGAMOUS PROTEIN; DEFICIENS PROTEIN; and SERUM RESPONSE FACTOR. Many MADS domain proteins have been found in species from all eukaryotic kingdoms. They play an important role in development, especially in plants where they have an important role in flower development.

Maf Transcription Factors [M0478897]
Maf transcription factors are a family of basic-leucine zipper transcription factors that are closely related to V-MAF ONCOGENE PROTEIN. The C-MAF PROTO-ONCOGENE PROTEIN was the first mammalian Maf transcription factor identified, and now the family is known to include a variety of other Maf proteins such as MAFB TRANSCRIPTION FACTOR; MAFF TRANSCRIPTION FACTOR; MAFG TRANSCRIPTION FACTOR; and MAFK TRANSCRIPTION FACTOR.

Maf Transcription Factors, Large [M0478899]
A family of high molecular weight Maf transcription factors that contain distinct activation domains.

Maf Transcription Factors, Small [M0478898]
A family of Maf Transcription Factors that lack activation domains. Small Maf proteins function as transcriptional repressors or form heterodimeric complexes to serve as transcriptional coactivators. Small Maf proteins include MafF, MafG, and MafK.

MafB Transcription Factor [M0479951]
A large maf protein that regulates HINDBRAIN development, contributes to CELL DIFFERENTIATION of MONOCYTES, and interacts with ETS-1 TRANSCRIPTION FACTOR.

MafF Transcription Factor [M0479953]
A small maf protein that forms dimers with NRF1 PROTEIN; NRF2 PROTEIN; and P45 NF-E2 PROTEIN. MafF complexes bind Maf recognition elements to regulate tissue-specific GENETIC TRANSCRIPTION.

MafG Transcription Factor [M0479952]
MafG is a ubiquitously expressed small maf protein that is involved in CELL DIFFERENTIATION of ERYTHROCYTES. It dimerizes with P45 NF-E2 PROTEIN and activates expression of ALPHA-GLOBIN and BETA-GLOBIN.

MafK Transcription Factor [M0220665]
A small Maf protein involved in differentiation of ERYTHROID CELLS. MafK was originally described as the small subunit of the NF-E2 Transcription Factor, but other small MAF PROTEINS also serve as NF-E2 subunits.

Magnesiocard [M0001844]

Magnesium Pidolate [M0018280]

Magnesium Sarcosylate [M0019444]

Major Core Protein lambda-1 [M0022700]

Major Core Protein sigma-2 [M0022701]

Major Core Proteins, Viral [M0022702]

Malate Dehydrogenase [M0012914]
An enzyme that catalyzes the conversion of (S)-malate and NAD+ to oxaloacetate and NADH. EC 1.1.1.37.

Malate Dehydrogenase (NADP+) [M0154845]
A light-activated enzyme that catalyzes the oxidation of (S)-malate to OXALOACETATE. It is involved in PYRUVATE metabolism and CARBON fixation.

Malate Synthase [M0012915]
An important enzyme in the glyoxylic acid cycle which reversibly catalyzes the synthesis of L-malate from acetyl-CoA and glyoxylate. This enzyme was formerly listed as EC 4.1.3.2.

Malonate-Semialdehyde Dehydrogenase (Acetylating) [M0144942]
An enzyme that catalyzes the oxidation of 3-oxopropanoate (malonate semialdehyde) to acetyl COENZYME A. It plays a role in the metabolism of BETA-ALANINE.

Mannitol Dehydrogenase [M0012997]

Mannose-6-Phosphate Isomerase [M0013002]
An enzyme that catalyzes the reversible isomerization of D-mannose-6-phosphate to form D-fructose-6-phosphate, an important step in glycolysis. EC 5.3.1.8.

Mannose-Binding Lectin [M0412169]
A specific mannose-binding member of the collectin family of lectins. It binds to carbohydrate groups on invading pathogens and plays a key role in the MANNOSE-BINDING LECTIN COMPLEMENT PATHWAY.

Mannose-Binding Lectins [M0114068]
A subclass of lectins that are specific for CARBOHYDRATES that contain MANNOSE.

Mannose-Binding Protein-Associated Serine Proteases [M0233323]
Serum serine proteases which participate in COMPLEMENT ACTIVATION. They are activated when complexed with the MANNOSE-BINDING LECTIN, therefore also known as Mannose-binding protein-Associated Serine Proteases (MASPs). They cleave COMPLEMENT C4 and COMPLEMENT C2 to form C4b2a, the CLASSICAL PATHWAY C3 CONVERTASE.

Mannosidases [M0013004]
Glycoside hydrolases that catalyze the hydrolysis of alpha or beta linked MANNOSE.

Mannosyl-Glycoprotein Endo-beta-N-Acetylglucosaminidase [M0025885]
A group of related enzymes responsible for the endohydrolysis of the di-N-acetylchitobiosyl unit in high-mannose-content glycopeptides and GLYCOPROTEINS.

Mannosyltransferases [M0013007]
Enzymes that catalyze the transfer of mannose from a nucleoside diphosphate mannose to an acceptor molecule which is frequently another carbohydrate. The group includes EC 2.4.1.32, EC 2.4.1.48, EC 2.4.1.54, and EC 2.4.1.57.

MAP Kinase Kinase 1 [M0208001]
An abundant 43-kDa mitogen-activated protein kinase kinase subtype with specificity for MITOGEN-ACTIVATED PROTEIN KINASE 1 and MITOGEN-ACTIVATED PROTEIN KINASE 3.

MAP Kinase Kinase 2 [M0216971]
A 44 kDa mitogen-activated protein kinase kinase with specificity for MITOGEN-ACTIVATED PROTEIN KINASE 1 and MITOGEN-ACTIVATED PROTEIN KINASE 3.

MAP Kinase Kinase 3 [M0242396]
A mitogen-activated protein kinase kinase with specificity for a subset of P38 MITOGEN-ACTIVATED PROTEIN KINASES that includes MITOGEN-ACTIVATED PROTEIN KINASE 12; MITOGEN-ACTIVATED PROTEIN KINASE 13; and MITOGEN-ACTIVATED PROTEIN KINASE 14.

MAP Kinase Kinase 4 [M0240274]
A mitogen-activated protein kinase kinase with specificity for JNK MITOGEN-ACTIVATED PROTEIN KINASES; P38 MITOGEN-ACTIVATED PROTEIN KINASES and the RETINOID X RECEPTORS. It takes part in a SIGNAL TRANSDUCTION pathway that is activated in response to cellular stress.

MAP Kinase Kinase 5 [M0247117]
A mitogen-activated protein kinase kinase with specificity for MITOGEN-ACTIVATED PROTEIN KINASE 7.

MAP Kinase Kinase 6 [M0260706]
A mitogen-activated protein kinase kinase with specificity for P38 MITOGEN-ACTIVATED PROTEIN KINASES.

MAP Kinase Kinase 6b [M0260702]

MAP Kinase Kinase 6c [M0260703]

MAP Kinase Kinase 7 [M0278483]
A mitogen-activated protein kinase kinase with specificity for JNK MITOGEN-ACTIVATED PROTEIN KINASES. It takes part in a SIGNAL TRANSDUCTION pathway that is activated in response to CYTOKINES.

MAP Kinase Kinase Kinase 1 [M0233961]
A 195-kDa MAP kinase kinase kinase with broad specificity for MAP KINASE KINASES. It is found localized in the CYTOSKELETON and can activate a variety of MAP kinase-dependent pathways.

MAP Kinase Kinase Kinase 2 [M0350337]
A 70-kDa MAP kinase kinase kinase with specificity for MAP KINASE KINASE 5. It is activated during the cellular response to GROWTH FACTORS, oxidative stress, and hyperosmotic conditions.

MAP Kinase Kinase Kinase 3 [M0242392]
A 70-kDa MAPK kinase kinase with specificity for MAP KINASE KINASE 5.

MAP Kinase Kinase Kinase 4 [M0281552]
A 180-kDa MAP kinase kinase kinase with specificity for MAP KINASE KINASE 4 and MAP KINASE KINASE 6.

MAP Kinase Kinase Kinase 5 [M0268521]
A 150-kDa MAP kinase kinase kinase that may play a role in the induction of APOPTOSIS. It has specificity for MAP KINASE KINASE 3; MAP KINASE KINASE 4; and MAP KINASE KINASE 6.

MAP Kinase Kinase Kinases [M0328033]
Mitogen-activated protein kinase kinase kinases (MAPKKKs) are serine-threonine protein kinases that initiate protein kinase signaling cascades. They phosphorylate MITOGEN-ACTIVATED PROTEIN KINASE KINASES; (MAPKKs) which in turn phosphorylate MITOGEN-ACTIVATED PROTEIN KINASES; (MAPKs).

MAPK-ERK Kinase Kinases [M0329022]

MAPK-ERK Kinases [M0331456]

Marijuana Receptor [M0443693]

Martricin [M0373259]

MASP-Related Protein [M0361077]

Mast Cell Tryptase [M0496669]

Mating Factor Receptor Ste2 [M0482291]

Mating Factor Receptor Ste3 [M0482290]

Matrix Attachment Region Binding Proteins [M0411489]
Proteins that bind to the MATRIX ATTACHMENT REGIONS of DNA.

Matrix Metalloproteinase 1 [M0188742]
A member of the metalloproteinase family of enzymes that is principally responsible for cleaving FIBRILLAR COLLAGEN. It can degrade interstitial collagens, types I, II and III.

Matrix Metalloproteinase 10 [M0197536]
A secreted matrix metalloproteinase that may play a role in matrix degradation during WOUND HEALING. It is expressed at high levels by KERATINOCYTES, suggesting its role in keratinocyte migration.

Matrix Metalloproteinase 11 [M0208619]
A secreted matrix metalloproteinase that is believed to play a role in EXTRACELLULAR MATRIX remodeling and cell fate determination during normal and pathological processes. Matrix metalloproteinase 11 was originally isolated in primary BREAST NEOPLASMS and may be involved in the process of tumorigenesis.

Matrix Metalloproteinase 12 [M0149080]
A secreted matrix metalloproteinase which is highly expressed by MACROPHAGES where it may play a role in INFLAMMATION and WOUND HEALING.

Matrix Metalloproteinase 13 [M0232202]
A secreted matrix metalloproteinase that plays a physiological role in the degradation of extracellular matrix found in skeletal tissues. It is synthesized as an inactive precursor that is activated by the proteolytic cleavage of its N-terminal propeptide.

Matrix Metalloproteinase 14 [M0286947]
A transmembrane domain-containing matrix metalloproteinase. It is synthesized as an inactive zymogen that is activated by the action of PROPROTEIN CONVERTASES such as FURIN. Matrix metalloproteinase 14 plays a direct role in the cleavage of proteins in the pericellular environment. In addition it can function indirectly by enzymatically activating the proprotein form of MATRIX METALLOPROTEINASE 15.

Matrix Metalloproteinase 15 [M0232699]
A transmembrane domain-containing matrix metalloproteinase that plays a role in the cleavage of proteins in the pericellular environment. It is synthesized as an inactive zymogen that is activated by the action of ENDOPEPTIDASES such as MATRIX METALLOPROTEINASE 14.

Matrix Metalloproteinase 16 [M0284099]
A transmembrane domain-containing matrix metalloproteinase. It is synthesized as an inactive zymogen that is activated by the proteolytic action of PROPROTEIN CONVERTASES. Matrix metalloproteinase 16 plays a direct role in the cleavage of proteins in the pericellular environment. In addition it can function indirectly by enzymatically activating the proprotein form of other MATRIX METALLOPROTEINASES such as the zymogen of MATRIX METALLOPROTEINASE 2.

Matrix Metalloproteinase 17 [M0485717]
A membrane-type metalloproteinase that is associated with the CELL MEMBRANE via a GLYCOSYL-PHOSPHATIDYLINOSITOL linkage. It is synthesized as an inactive zymogen that is activated by the action of PROPROTEIN CONVERTASES such as FURIN.

Matrix Metalloproteinase 2 [M0328128]
A secreted endopeptidase homologous with INTERSTITIAL COLLAGENASE, but which possesses an additional fibronectin-like domain.

Matrix Metalloproteinase 20 [M0271042]
A secreted matrix metalloproteinase that is the predominant proteolytic activity in the enamel matrix. The enzyme has a high specificity for dental enamel matrix protein AMELOGENIN.

Matrix Metalloproteinase 3 [M0028707]
An extracellular endopeptidase of vertebrate tissues similar to MATRIX METALLOPROTEINASE 1. It digests PROTEOGLYCAN; FIBRONECTIN; COLLAGEN types III, IV, V, and IX, and activates procollagenase. (Enzyme Nomenclature, 1992)

Matrix Metalloproteinase 7 [M0198169]
The smallest member of the MATRIX METALLOPROTEINASES. It plays a role in tumor progression.

Matrix Metalloproteinase 8 [M0206959]
A member of the MATRIX METALLOPROTEINASES that cleaves triple-helical COLLAGEN types I, II, and III.

Matrix Metalloproteinase 9 [M0170326]
An endopeptidase that is structurally similar to MATRIX METALLOPROTEINASE 2. It degrades GELATIN types I and V; COLLAGEN TYPE IV; and COLLAGEN TYPE V.

Matrix Metalloproteinases [M0328197]
A family of zinc-dependent metalloendopeptidases that are involved in the degradation of EXTRACELLULAR MATRIX components. EC 3.4.24.-.

Matrix Metalloproteinases, Membrane-Associated [M0232705]
Matrix metalloproteinases that are associated with the CELL MEMBRANE, either through transmembrane domains or GLYCOSYLPHOSPHATIDYLINOSITOL ANCHORS. Membrane-type matrix metalloproteinases may act within the pericellular environment to influence the process of CELL MIGRATION.

Matrix Metalloproteinases, Secreted [M0493993]
A subclass of matrix metalloproteinases that are secreted into the pericellular space.

Maturation-Promoting Factor [M0024733]
Protein kinase that drives both the mitotic and meiotic cycles in all eukaryotic organisms. In meiosis it induces immature oocytes to undergo meiotic maturation. In mitosis it has a role in the G2/M phase transition. Once activated by CYCLINS; MPF directly phosphorylates some of the proteins involved in nuclear envelope breakdown, chromosome condensation, spindle assembly, and the degradation of cyclins. The catalytic subunit of MPF is PROTEIN P34CDC2.

Maxatase [M0020690]

Maxilase [M0477124]

Maxomat [M0475571]

MCM1 Protein [M0195072]
A sequence-specific DNA-binding protein that plays an essential role as a global regulator of yeast cell cycle control. It contains a MADS-box domain within the N-terminal 56 amino acids. It is one of the four founder proteins that structurally define the superfamily of MADS DOMAIN PROTEINS.

MDL-71,782 A [M0000789]

Measles Fusion Protein [M0022726]

Medium-Chain Acyl CoA-Binding Protein [M0377491]

Medphalan [M0013329]

Megacin [M0013291]

Megacin A [M0013289]

Megacins [M0013290]
Bacteriocins elaborated by mutant strains of Bacillus megaterium. They are protein or protein-lipopolysaccharide complexes lethal to other strains of the same species.

M�gamylase [M0477125]

Melanocortins [M0493657]
Peptides derived from pro-opiomelanocortin (POMC) which can stimulate MELANOCYTES or CORTICOTROPHS. Melanocortins include ACTH; ALPHA-MSH; and other peptides such as BETA-MSH and GAMMA-MSH, derived from other fragments of POMC. These peptides act through a variety of MELANOCORTIN RECEPTORS to control different functions including steroidogenesis, energy homeostasis, feeding, and skin pigmentation.

Melanocyte-Stimulating Hormones [M0014155]
Peptides with the ability to stimulate pigmented cells MELANOCYTES in mammals and MELANOPHORES in lower vertebrates. By stimulating the synthesis and distribution of MELANIN in these pigmented cells, they increase coloration of skin and other tissue. MSHs, derived from pro-opiomelanocortin (POMC), are produced by MELANOTROPHS in the INTERMEDIATE LOBE OF PITUITARY; CORTICOTROPHS in the ANTERIOR LOBE OF PITUITARY, and the hypothalamic neurons in the ARCUATE NUCLEUS.

Meldopa [M0474250]

Melitten [M0013325]
Basic polypeptide from the venom of the honey bee (Apis mellifera); it contains 62 amino acids, has cytolytic properties, causes contracture of muscle, releases histamine and disrupts surface tension, probably due to lysis of cell and mitochondrial membranes. Synonyms: melittin; melliten.

Melphalan [M0013330]
An alkylating nitrogen mustard that is used as an antineoplastic in the form of the levo isomer - MELPHALAN, the racemic mixture - MERPHALAN, and the dextro isomer - MEDPHALAN; toxic to bone marrow, but little vesicant action; potential carcinogen.

Membrane Fusion Proteins [M0476481]
Proteins that catalyze MEMBRANE FUSION.

Membrane Glycoproteins [M0013336]
Glycoproteins found on the membrane or surface of cells.

Membrane Proteins [M0013341]
Proteins which are found in membranes including cellular and intracellular membranes. They consist of two types, peripheral and integral proteins. They include most membrane-associated enzymes, antigenic proteins, transport proteins, and drug, hormone, and lectin receptors.

Membrane Transport Proteins [M0379230]
Membrane proteins whose primary function is to facilitate the transport of molecules across a biological membrane. Included in this broad category are proteins involved in active transport (BIOLOGICAL TRANSPORT, ACTIVE), facilitated transport and ION CHANNELS.

Membrane-Associated Guanylate Kinase [M0075052]

Menaquinone Reductases [M0018354]

Menogon [M0473964]

Menotropins [M0013384]
Extracts of urine from menopausal women that contain high concentrations of pituitary gonadotropins, FOLLICLE STIMULATING HORMONE and LUTEINIZING HORMONE. Menotropins are used to treat infertility. The FSH:LH ratio and degree of purity vary in different preparations.

mentopin Acetylcystein [M0447479]

Meprin [M0373100]

Meromyosin Subfragments [M0375373]

Merosin [M0012197]

Merozoite Surface Protein 1 [M0029774]
A surface protein found on Plasmodium species which induces a T-cell response. The antigen is polymorphic, sharing amino acid sequence homology among PLASMODIUM FALCIPARUM; PLASMODIUM CHABAUDI; PLASMODIUM VIVAX; and PLASMODIUM YOELII.

Mesalamine [M0029386]
An anti-inflammatory agent, structurally related to the SALICYLATES, which is active in INFLAMMATORY BOWEL DISEASE. It is considered to be the active moiety of SULPHASALAZINE. (From Martindale, The Extra Pharmacopoeia, 30th ed)

Mesalamine Hydrochloride [M0329125]

Mesalamine Monosodium Salt [M0329124]

Mesasal [M0029392]

Metalcaptase [M0016121]

Metalloendopeptidases [M0013502]
ENDOPEPTIDASES which use a metal such as ZINC in the catalytic mechanism.

Metalloexopeptidases [M0449116]
EXOPEPTIDASES which use a metal such as ZINC in the catalytic mechanism.

Metalloproteases [M0449114]
Proteases which use a metal, normally ZINC, in the catalytic mechanism. This group of enzymes is inactivated by metal CHELATORS.

Metalloproteins [M0013505]
Proteins that have one or more tightly bound metal ions forming part of their structure. (Dorland, 28th ed)

Metallothionein [M0013507]
A low-molecular-weight (approx. 10 kD) protein occurring in the cytoplasm of kidney cortex and liver. It is rich in cysteinyl residues and contains no aromatic amino acids. Metallothionein shows high affinity for bivalent heavy metals.

Metallothionein A [M0013508]

Metallothionein B [M0013509]

Metallothionein I [M0013510]

Metallothionein II [M0013511]

Metallothionein IIA [M0013512]

Metastasis Suppressor Proteins [M0374858]

Methemoglobin [M0013563]

Methemoglobin Reductase [M0013564]
The soluble, erythrocyte form of cytochrome-B(5) reductase. It catalyzes the reduction of methemoglobin (ferrihemoglobin) to hemoglobin (ferrohemoglobin).

Methenyltetrahydrofolate Cyclohydrolase [M0076651]
An aminohydrolase that catalyzes the hydrolysis of 5,10-methenyltetrahydrofolate to 10-formyltetrahydrofolate. In most higher eucaryotic organisms this enzyme also includes METHYLENETETRAHYDROFOLATE DEHYDROGENASE (NADP) and FORMATE-TETRAHYDROFOLATE LIGASE activities.

Methionine [M0013575]
A sulfur containing essential amino acid that is important in many body functions. It is a chelating agent for heavy metals.

Methionine Adenosyltransferase [M0013578]
An enzyme that catalyzes the synthesis of S-adenosylmethionine from methionine and ATP. EC 2.5.1.6.

Methionine Sulfoximine [M0013579]

Methionine, DL-Isomer [M0330130]

Methionine-tRNA Ligase [M0013580]
An enzyme that activates methionine with its specific transfer RNA. EC 6.1.1.10.

Methoxyleucine Aminopeptidase [M0012374]

Methyl-CpG-Binding Protein 2 [M0208047]
A DNA-binding protein that interacts with methylated CPG ISLANDS. It plays a role in repressing GENETIC TRANSCRIPTION and is frequently mutated in RETT SYNDROME.

Methyladenine Receptors [M0018616]

Methyldopa [M0013626]
An alpha-2 adrenergic agonist that has both central and peripheral nervous system effects. Its primary clinical use is as an antihypertensive agent.

Methyldopate [M0013627]

Methylenetetrahydrofolate Dehydrogenase (NAD+) [M0013633]
A NAD-dependent oxidoreductase that catalyzes the conversion of 5,10-methylenetetrahydrofolate to 5,10-methenyl-tetrahdyrofolate. It has been found in a variety of microorganisms.

Methylenetetrahydrofolate Dehydrogenase (NADP) [M0013632]
An NADP-dependent oxidoreductase that catalyses the conversion of 5,10-methyleneterahydrofolate to 5,10-methenyl-tetrahydrofolate. In higher eukaryotes a trifunctional enzyme exists with additional METHENYLTETRAHYDROFOLATE CYCLOHYDROLASE and FORMATE-TETRAHYDROFOLATE LIGASE activity. The enzyme plays an important role in the synthesis of 5-methyltetrahydrofolate, the methyl donor for the VITAMIN B12-dependent remethylation of HOMOCYSTEINE to METHIONINE via METHIONINE SYNTHETASE.

Methylenetetrahydrofolate Reductase (NADPH2) [M0137645]
A flavoprotein amine oxidoreductase that catalyzes the reversible conversion of 5-METHYLTETRAHYDROFOLATE to 5,10-METHYLENETETRAHYDROFOLATE. This enzyme was formerly classified as EC 1.1.1.171.

Methylhistidines [M0013644]
Histidine substituted in any position with one or more methyl groups.

Methylmalonate-Semialdehyde Dehydrogenase (Acylating) [M0144948]
An enzyme that plays a role in the VALINE; LEUCINE; and ISOLEUCINE catabolic pathways by catalyzing the oxidation of 2-methyl-3-oxopropanate to propanoyl-CoA using NAD+ as a coenzyme. Methylmalonate semialdehyde dehydrogenase deficiency is characterized by elevated BETA-ALANINE and 3-HYDROXYPROPIONIC ACID.

Methylmalonyl-CoA Decarboxylase [M0078512]
A carboxy-lyase that catalyzes the decarboxylation of (S)-2-Methyl-3-oxopropanoyl-CoA to propanoyl-CoA. In microorganisms the reaction can be coupled to the vectorial transport of SODIUM ions across the cytoplasmic membrane.

Methylmalonyl-CoA Mutase [M0013647]
An enzyme that catalyzes the conversion of methylmalonyl-CoA to succinyl-CoA by transfer of the carbonyl group. It requires a cobamide coenzyme. A block in this enzymatic conversion leads to the metabolic disease, methylmalonic aciduria. EC 5.4.99.2.

Methylpurine DNA Glycosylase [M0073349]

Methyltransferases [M0013670]
A subclass of enzymes of the transferase class that catalyze the transfer of a methyl group from one compound to another. (Dorland, 28th ed) EC 2.1.1.

Methyltyrosines [M0013671]
A group of compounds that are methyl derivatives of the amino acid TYROSINE.

Metmyoglobin [M0013678]
Myoglobin which is in the oxidized ferric or hemin form. The oxidation causes a change in color from red to brown.

Metrodin [M0013385]

Metyrosine [M0329127]

Mg-5-Longoral [M0001838]

MICRhoGAM [M0373304]

Microbial Collagenase [M0004633]
A metalloproteinase which degrades helical regions of native collagen to small fragments. Preferred cleavage is -Gly in the sequence -Pro-Xaa-Gly-Pro-. Six forms (or 2 classes) have been isolated from Clostridium histolyticum that are immunologically cross-reactive but possess different sequences and different specificities. Other variants have been isolated from Bacillus cereus, Empedobacter collagenolyticum, Pseudomonas marinoglutinosa, and species of Vibrio and Streptomyces. EC 3.4.24.3.

Micrococcal Nuclease [M0013774]
An enzyme that catalyzes the endonucleolytic cleavage to 3'-phosphomononucleotide and 3'-phospholigonucleotide end-products. It can cause hydrolysis of double- or single-stranded DNA or RNA. (From Enzyme Nomenclature, 1992) EC 3.1.31.1.

Microcystins [M0490627]
Cyclic heptapeptides found in MICROCYSTIS and other CYANOBACTERIA. Hepatotoxic and carcinogenic effects have been noted. They are sometimes called cyanotoxins, which should not be confused with chemicals containing a cyano group (CN) which are toxic.

Microfibril Collagen Hemostat [M0004787]
A topical hemostatic agent prepared from collagen.

Microfilament Proteins [M0013781]
Filaments which are composed primarily of actin and found in the cytoplasmic matrix of almost all cells. They are often associated with microtubules and may play a role in cytoskeletal function and/or mediate movement of the cell or the organelles within the cell.

Microphthalmia-Associated Transcription Factor [M0219714]
A basic helix-loop-helix leucine zipper transcription factor that regulates the CELL DIFFERENTIATION and development of a variety of cell types including MELANOCYTES; OSTEOCLASTS; and RETINAL PIGMENT EPITHELIUM. Mutations in MITF protein have been associated with OSTEOPETROSIS and WAARDENBURG'S SYNDROME.

Microsomal Epoxide Hydrolase [M0007611]

Microtubule Proteins [M0013829]
Proteins found in the microtubules.

Microtubule-Associated Protein 1 [M0013832]

Microtubule-Associated Protein 2 [M0013833]

Microtubule-Associated Protein 3 [M0013834]

Microtubule-Associated Proteins [M0013835]
High molecular weight proteins found in the MICROTUBULES of the cytoskeletal system. Under certain conditions they are required for TUBULIN assembly into the microtubules and stabilize the assembled microtubules.

Microvitellogenin [M0022815]
A protein found in HEMOLYMPH and OVA of adult female MANDUCA, tobacco hornworm moth.

Mikamycin [M0375357]
An antibiotic complex originally isolated from Streptomyces mitakaenis. It contains two principle ingredients: STREPTOGRAMIN A (mikamycin A) and STREPTOGRAMIN B (mikamycin B).

mil-raf Protein Kinases [M0461522]

Milid [M0373165]

Milisucre [M0434517]

Milk Proteins [M0013890]
The major protein constituents of milk are CASEINS and whey proteins such as LACTALBUMIN and LACTOGLOBULINS. IMMUNOGLOBULINS occur in high concentrations in COLOSTRUM and in relatively lower concentrations in milk. (Singleton and Sainsbury, Dictionary of Microbiology and Molecular Biology, 2d ed, p554)

Mimosine [M0013894]
3-Hydroxy-4-oxo-1(4H)-pyridinealanine. An antineoplastic alanine-substituted pyridine derivative isolated from Leucena glauca.

Miniparamyosin [M0022047]

Minor Lymphocyte Stimulatory Antigens [M0025504]
Endogenous superantigens responsible for inducing strong proliferative responses in T-cells in mixed lymphocyte reactions (see LYMPHOCYTE CULTURE TEST, MIXED). They are encoded by mouse mammary tumor viruses that have integrated into the germ line as DNA proviruses (MINOR LYMPHOCYTE STIMULATORY LOCI).

Minor Sigma Factor [M0019832]

MIP-1alpha [M0028875]

MIP-1beta [M0028876]

Mitochondrial ADP, ATP Translocases [M0000348]
A class of nucleotide translocases found abundantly in mitochondria that function as integral components of the inner mitochondrial membrane. They facilitate the exchange of ADP and ATP between the cytosol and the mitochondria, thereby linking the subcellular compartments of ATP production to those of ATP utilization.

Mitochondrial Assembly Factor hsp60 [M0028188]

Mitochondrial Electron Transport Chain Complex Proteins [M0449187]

Mitochondrial Electron Transport Complex I [M0449185]

Mitochondrial Electron Transport Complex II [M0449189]

Mitochondrial Electron Transport Complex III [M0449353]

Mitochondrial Electron Transport Complex IV [M0449191]

Mitochondrial Heat Shock Protein 70 [M0264343]

Mitochondrial Initiation Factors [M0419809]
Peptide initiation factors found in MITOCHONDRIA. Although specific factors may closely resemble those found in prokaryotes, they are eukaryotic factors and classed here under eukaryotic initiation factors.

Mitochondrial Membrane Transport Proteins [M0403944]
Proteins involved in the transport of specific substances across the membranes of the MITOCHONDRIA.

Mitochondrial Monocarboxylate Translocator [M0389404]

Mitochondrial Pore Protein [M0479895]

Mitochondrial Proteins [M0369371]
Proteins encoded by the mitochondrial genome or proteins encoded by the nuclear genome that are imported to and resident in the MITOCHONDRIA.

Mitochondrial Proton-Translocating ATPases [M0374090]
Proton-translocating ATPases responsible for ADENOSINE TRIPHOSPHATE synthesis in the MITOCHONDRIA. They derive energy from the respiratory chain-driven reactions that develop high concentrations of protons within the intermembranous space of the mitochondria.

Mitochondrial Telomere-Binding Proteins [M0194753]

Mitogen-Activated Protein Kinase 1 [M0029623]
A proline-directed serine/threonine protein kinase which mediates signal transduction from the cell surface to the nucleus. Activation of the enzyme by phosphorylation leads to its translocation into the nucleus where it acts upon specific transcription factors. p40 MAPK and p41 MAPK are isoforms.

Mitogen-Activated Protein Kinase 10 [M0241808]
A c-jun amino-terminal kinase that is found predominantly within NEURONS of the BRAIN, suggesting a role in stress-induced neuronal APOPTOSIS. Several isoforms of the protein with molecular sizes of 47 kDa and 52 kDa exist due to multiple ALTERNATIVE SPLICING.

Mitogen-Activated Protein Kinase 11 [M0362623]
A 38-kDa mitogen-activated protein kinase that is expressed in a broad variety of cell types. It may play a role in regulating cell proliferation and TRANSCRIPTION FACTOR AP-1 dependent transcription.

Mitogen-Activated Protein Kinase 12 [M0259701]
A 38-kDa mitogen-activated protein kinase found primarily in SKELETAL MUSCLE.

Mitogen-Activated Protein Kinase 13 [M0278800]
A 38-kDa mitogen-activated protein kinase found expressed at high levels in LUNG; KIDNEY; TESTIS; PANCREAS; and SMALL INTESTINE. It may play a role in regulating functions such as CELL DIFFERENTIATION and APOPTOSIS of EPITHELIAL CELLS.

Mitogen-Activated Protein Kinase 14 [M0417034]
A 38-kDa mitogen-activated protein kinase that is abundantly expressed in a broad variety of cell types. It is involved in the regulation of cellular stress responses as well as the control of proliferation and survival of many cell types. The kinase activity of the enzyme is inhibited by the pyridinyl-imidazole compound SB 203580.

Mitogen-Activated Protein Kinase 3 [M0178617]
A 44-kDa extracellular signal-regulated MAP kinase that may play a role the initiation and regulation of MEIOSIS; MITOSIS; and postmitotic functions in differentiated cells. It phosphorylates a number of TRANSCRIPTION FACTORS; and MICROTUBULE-ASSOCIATED PROTEINS.

Mitogen-Activated Protein Kinase 6 [M0188319]
A 97-kDa extracellular signal-regulated MAP kinase. Mitogen-activated protein kinase 6 levels increase during cellular differentiation, while in proliferating cells the enzyme is degraded rapidly via the PROTEASOME ENDOPEPTIDASE COMPLEX.

Mitogen-Activated Protein Kinase 7 [M0250720]
A 110-kDa extracellular signal-regulated MAP kinase that is activated in response to cellular stress and by GROWTH FACTOR RECEPTORS-mediated pathways.

Mitogen-Activated Protein Kinase 7 Isoform 1 [M0460936]

Mitogen-Activated Protein Kinase 7 Isoform 2 [M0460937]

Mitogen-Activated Protein Kinase 8 [M0362611]
A c-jun amino-terminal kinase that is activated by environmental stress and pro-inflammatory cytokines. Several isoforms of the protein with molecular sizes of 43 and 48 KD exist due to multiple ALTERNATIVE SPLICING.

Mitogen-Activated Protein Kinase 9 [M0239058]
A c-jun amino-terminal kinase that is activated by environmental stress and pro-inflammatory cytokines. Several isoforms of the protein with molecular sizes of 48 and 54 KD exist due to multiple ALTERNATIVE SPLICING.

Mitogen-Activated Protein Kinase Kinases [M0328038]
A serine-threonine protein kinase family whose members are components in protein kinase cascades activated by diverse stimuli. These MAPK kinases phosphorylate MITOGEN-ACTIVATED PROTEIN KINASES and are themselves phosphorylated by MAP KINASE KINASE KINASES. JNK kinases (also known as SAPK kinases) are a subfamily.

Mitogen-Activated Protein Kinases [M0328039]
A superfamily of PROTEIN-SERINE-THREONINE KINASES that are activated by diverse stimuli via protein kinase cascades. They are the final components of the cascades, activated by phosphorylation by MITOGEN-ACTIVATED PROTEIN KINASE KINASES which in turn are activated by mitogen-activated protein kinase kinase kinases (MAP KINASE KINASE KINASES).

Mixed Function Oxygenases [M0010768]
Widely distributed enzymes that carry out oxidation-reduction reactions in which one atom of the oxygen molecule is incorporated into the organic substrate; the other oxygen atom is reduced and combined with hydrogen ions to form water. They are also known as monooxygenases or hydroxylases. These reactions require two substrates as reductants for each of the two oxygen atoms. There are different classes of monooxygenases depending on the type of hydrogen-providing cosubstrate (COENZYMES) required in the mixed-function oxidation.

Mixtard [M0011441]

MK-421 [M0007331]

MK-422 [M0363630]

MK-521 [M0373302]

MleI Endonuclease [M0023451]

Mn Catalase [M0003616]

Mn-Superoxide Dismutase [M0020831]

Modified Immune Globulin (Anti-Echovirus Antibody) [M0025525]

Molecular Chaperones [M0028186]
A family of cellular proteins that mediate the correct assembly or disassembly of other polypeptides, and in some cases their assembly into oligomeric structures, but which are not components of those final structures. It is believed that chaperone proteins assist polypeptides to self-assemble by inhibiting alternative assembly pathways that produce nonfunctional structures. Some classes of molecular chaperones are the nucleoplasmins, the CHAPERONINS, the HEAT-SHOCK PROTEINS 70, and the HSP90 HEAT-SHOCK PROTEINS.

Molecular Motor Proteins [M0030059]
Proteins that are involved in or cause CELL MOVEMENT such as the rotary structures (flagellar motor) or the structures whose movement is directed along cytoskeletal filaments (MYOSIN; KINESIN; and DYNEIN motor families).

Molecular Vaccines [M0022455]

Molybdoferredoxin [M0014005]
A non-heme iron-sulfur protein isolated from Clostridium pasteurianum and other bacteria. It is a component of NITROGENASE, which is active in nitrogen fixation, and consists of two subunits with molecular weights of 59.5 kDa and 50.7 kDa, respectively.

Mono(ADP-Ribose) Transferases [M0412050]
Enzymes that catalyze the transfer of one ADP-ribose moiety from NAD+ to an amino acid residue in specific protein substrates. This reaction is catalyzed by prokaryotic and eukaryotic enzymes. Mono-ADP-ribosylation is a mechanism of action common to several bacterial toxins.

Monoacylglycerol Lipases [M0014025]
An enzyme that catalyzes the hydrolysis of glycerol monoesters of long-chain fatty acids EC 3.1.1.23.

Monoamine Oxidase [M0014026]
An enzyme that catalyzes the oxidative deamination of naturally occurring monoamines. It is a flavin-containing enzyme that is localized in mitochondrial membranes, whether in nerve terminals, the liver, or other organs. Monoamine oxidase is important in regulating the metabolic degradation of catecholamines and serotonin in neural or target tissues. Hepatic monoamine oxidase has a crucial defensive role in inactivating circulating monoamines or those, such as tyramine, that originate in the gut and are absorbed into the portal circulation. (From Goodman and Gilman's, The Pharmacological Basis of Therapeutics, 8th ed, p415) EC 1.4.3.4.

Monoamine Oxidase B [M0014028]

Monocarboxylic Acid Transporters [M0076801]
A family of proteins involved in the transport of monocarboxylic acids such as LACTIC ACID and PYRUVIC ACID across cellular membranes.

Monoclate [M0008152]

Monocyte Chemoattractant Proteins [M0028314]
Chemokines that are chemoattractants for monocytes. These CC chemokines (cysteines adjacent) number at least three including CHEMOKINE CCL2.

Monoester Lipase [M0012546]

Monoferric Transferrins [M0021806]

Monoiodotyrosine [M0011670]
A product from the iodination of tyrosine. In the biosynthesis of thyroid hormones (THYROXINE and TRIIODOTHYRONINE), tyrosine is first iodized to monoiodotyrosine.

Monomeric Clathrin Assembly Proteins [M0404566]
A subclass of clathrin assembly proteins that occur as monomers.

Monomeric GTP-Binding Proteins [M0328207]
A class of monomeric, low molecular weight (20-25 kDa) GTP-binding proteins that regulate a variety of intracellular processes. The GTP bound form of the protein is active and limited by its inherent GTPase activity, which is controlled by an array of GTPase activators, GDP dissociation inhibitors, and guanine nucleotide exchange factors. This enzyme was formerly listed as EC 3.6.1.47

Monophenol Monooxygenase [M0022202]
An enzyme of the oxidoreductase class that catalyzes the reaction between L-tyrosine, L-dopa, and oxygen to yield L-dopa, dopaquinone, and water. It is a copper protein that acts also on catechols, catalyzing some of the same reactions as CATECHOL OXIDASE. EC 1.14.18.1.

Monopril [M0352132]

Monosaccharide Transport Proteins [M0014041]
A large group of membrane transport proteins that shuttle MONOSACCHARIDES across CELL MEMBRANES.

Morphine Glucuronyltransferase [M0022221]

Morphine Receptor [M0026476]

Motilin [M0014098]
A peptide of about 22-amino acids isolated from the DUODENUM. At low pH it inhibits gastric motor activity, whereas at high pH it has a stimulating effect.

Motility Proteins [M0493141]

mPPARgamma1 [M0199117]

mPPARgamma2 [M0199118]

mRNA Cleavage and Polyadenylation Factors [M0195409]
Factors that are involved in directing the cleavage and POLYADENYLATION of the of MESSENGER RNA near the site of the RNA 3' POLYADENYLATION SIGNALS.

MSH Release-Inhibiting Hormone [M0014157]
A hypothalamic tripeptide, enzymatic degradation product of OXYTOCIN, that inhibits the release of MELANOCYTE-STIMULATING HORMONES.

MSP1, P. vivax [M0029775]

MSX1 Transcription Factor [M0214648]
A homeodomain protein that interacts with TATA-BOX BINDING PROTEIN. It represses GENETIC TRANSCRIPTION of target GENES and plays a critical role in ODONTOGENESIS.

mu-Conotoxins [M0333358]

Mucins [M0014159]
High molecular weight mucoproteins that form a protective biofilm on the surface of EPITHELIAL CELLS where they provide a barrier to particulate matter and microorganisms. Membrane-anchored mucins may have additional roles concerned with protein interactions at the cell surface.

Muciteran [M0447440]

Mucomyst [M0000174]

Mucoproteins [M0014177]
Conjugated proteins in which mucopolysaccharides are combined with proteins. The mucopolysaccharide moiety is the predominant group with the protein making up only a small percentage of the total weight.

Mucosil [M0447481]

Mucosolvin [M0000175]

Mucozym [M0463078]

Mukodin [M0003350]

Multidrug Resistance-Associated Proteins [M0238823]
A sequence-related subfamily of ATP-BINDING CASSETTE TRANSPORTERS that actively transport organic substrates. Although considered organic anion transporters, a subset of proteins in this family have also been shown to convey drug resistance to neutral organic drugs. Their cellular function may have clinical significance for CHEMOTHERAPY in that they transport a variety of ANTINEOPLASTIC AGENTS. Overexpression of proteins in this class by NEOPLASMS is considered a possible mechanism in the development of multidrug resistance (DRUG RESISTANCE, MULTIPLE). Although similar in function to P-GLYCOPROTEINS, the proteins in this class share little sequence homology to the p-glycoprotein family of proteins.

Multienzyme Complexes [M0014188]
Systems of enzymes which function sequentially by catalyzing consecutive reactions linked by common metabolic intermediates. They may involve simply a transfer of water molecules or hydrogen atoms and may be associated with large supramolecular structures such as MITOCHONDRIA or RIBOSOMES.

Multiprotein Complexes [M0332992]
Macromolecular complexes formed from the association of defined protein subunits.

Mumps Virus Fusion Protein [M0022731]

Munc18 Proteins [M0195810]
A family of proteins involved in intracellular membrane trafficking. They interact with SYNTAXINS and play important roles in vesicular docking and fusion during EXOCYTOSIS. Their name derives from the fact that they are related to Unc-18 protein, C elegans.

Munc18-1 Protein [M0358803]

Munc18-2 Protein [M0284501]

Munc18-3 Protein [M0284500]

Mung Bean Nuclease [M0024107]

Mur-NAc-L-Ala-D-isoGln [M0000192]

Muramidase [M0014214]
A basic enzyme that is present in saliva, tears, egg white, and many animal fluids. It functions as an antibacterial agent. The enzyme catalyzes the hydrolysis of 1,4-beta-linkages between N-acetylmuramic acid and N-acetyl-D-glucosamine residues in peptidoglycan and between N-acetyl-D-glucosamine residues in chitodextrin. EC 3.2.1.17.

Muramoylpentapeptide Carboxypeptidase [M0003410]
Enzyme which catalyzes the peptide cross-linking of nascent CELL WALL; PEPTIDOGLYCAN.

Muromonab-CD3 [M0025653]
Anti-CD3 monoclonal antibody that exerts immunosuppressive effects by inducing peripheral T-cell depletion and modulation of the T-cell receptor complex (CD3/Ti). This biochemically purified IMMUNOGLOBULIN G is obtained through the fusion of mouse myeloma cells to lymphocytes from immunized animals to produce hybridomas that secrete specific antibodies to the T3 (CD3) antigens of human T-lymphocytes. It is often used as an IMMUNOSUPPRESSIVE AGENTS in TRANSPLANTATION.

Muscle Proteins [M0014239]
The protein constituents of muscle, the major ones being ACTINS and MYOSINS. More than a dozen accessory proteins exist including TROPONIN; TROPOMYOSIN; and DYSTROPHIN.

Mutansucrase [M0020720]

Mutant Chimeric Proteins [M0475666]
Proteins produced from GENES that have mutated by the fusing of protein coding regions of more than one gene.

Mutant Proteins [M0475665]
Proteins produced from GENES that have acquired MUTATIONS.

MutS DNA Mismatch-Binding Protein [M0191673]
A methyl-directed mismatch DNA REPAIR protein that has weak ATPASE activity. MutS was originally described in ESCHERICHIA COLI.

MutS Homolog 2 Protein [M0225463]
MutS homolog 2 protein is found throughout eukaryotes and is a homolog of the MUTS DNA MISMATCH-BINDING PROTEIN. It plays an essential role in meiotic RECOMBINATION and DNA REPAIR of mismatched NUCLEOTIDES.

Mycobacillin [M0014280]
A cyclic polypeptide antibiotic isolated from culture filtrates of Bacillus subtilis that acts as an antifungal agent.

Myelin Basic Proteins [M0007363]
A group of 7 proteins produced from a single gene by alternate splicing found in central and peripheral nervous system myelin. The major basic protein (MBP) has long been of interest because it is the antigen, that, when injected into an animal, elicits a cellular immune response that produces the CNS autoimmune disease called experimental allergic encephalomyelitis (ENCEPHALOMYELITIS, ALLERGIC). In the peripheral nervous system, myelin basic protein 18.5-kDa is often referred to as the P1 protein. (From Siegel et al., Basic Neurochemistry, 5th ed, p130, 133)

Myelin P0 Protein [M0028366]
A protein that accounts for more than half of the peripheral nervous system myelin protein. The extracellular domain of this protein is believed to engage in adhesive interactions and thus hold the myelin membrane compact. It can behave as a homophilic adhesion molecule through interactions with its extracellular domains. (From J Cell Biol 1994;126(4):1089-97)

Myelin P2 Protein [M0028370]
A positively charged protein found in peripheral nervous system myelin. Sensitive immunological techniques have demonstrated that P2 is expressed in small amounts of central nervous system myelin sheaths of some species. It is an antigen for experimental allergic neuritis (NEURITIS, EXPERIMENTAL ALLERGIC), the peripheral nervous system counterpart of experimental allergic encephalomyelitis. (From Siegel et al., Basic Neurochemistry, 5th ed, p133)

Myelin Proteins [M0014318]
Proteins found in the myelin sheath. The major proteins of central nervous system myelin include: MYELIN PROTEOLIPID PROTEIN; MYELIN BASIC PROTEINS; and MYELIN-ASSOCIATED GLYCOPROTEIN. The major proteins of peripheral nervous system myelin include: MYELIN BASIC PROTEINS (myelin P1 protein and MYELIN P2 PROTEIN); MYELIN P0 PROTEIN; and MYELIN-ASSOCIATED GLYCOPROTEIN.

Myelin Proteolipid Protein [M0028362]
A myelin protein that is the major component of the organic solvent extractable lipoprotein complexes of whole brain. It has been the subject of much study because of its unusual physical properties. It remains soluble in chloroform even after essentially all of its bound lipids have been removed. (From Siegel et al., Basic Neurochemistry, 4th ed, p122)

Myelin-Associated Glycoprotein [M0028363]
A myelin protein found in the periaxonal membrane of both the central and peripheral nervous systems myelin sheaths. It has a structure that is similar to members of the Ig superfamily that participate in cell adhesion. (From Siegel et al., Basic Neurochemistry, 5th ed, p132)

Myeloblastin [M0161951]
A polymorphonuclear leukocyte-derived serine protease that degrades proteins such as ELASTIN; FIBRONECTIN; LAMININ; VITRONECTIN; and COLLAGEN. It is named for its ability to control myeloid cell growth and differentiation.

Myeloid Differentiation Factor 88 [M0178953]
An intracellular signaling adaptor protein that plays a role in TOLL-LIKE RECEPTOR and INTERLEUKIN 1 RECEPTORS signal transduction. It forms a signaling complex with the activated cell surface receptors and members of the IRAK KINASES.

Myeloid-Lymphoid Leukemia Protein [M0209080]
Myeloid-lymphoid leukemia protein is a transcription factor that maintains high levels of HOMEOTIC GENE expression during development. The GENE for myeloid-lymphoid leukemia protein is commonly disrupted in LEUKEMIA and combines with over 40 partner genes to form FUSION ONCOGENE PROTEINS.

Myeloma Proteins [M0014330]
Abnormal immunoglobulins characteristic of MULTIPLE MYELOMA.

Myo-Inositol-1-Phosphate Synthase [M0011376]
An enzyme that catalyzes the formation of myo-inositol-1-phosphate from glucose-6-phosphate in the presence of NAD. EC 5.5.1.4.

Myocardial Depressant Factor [M0014336]
A low molecular weight peptide of about 800-1000 having a negative inotropic effect. It is released into the circulation during experimental hemorrhagic pancreatitis, severe ischemia, and postoligemic shock.

MyoD Protein [M0026632]
A myogenic regulatory factor that controls myogenesis. Though it is not clear how its function differs from the other myogenic regulatory factors, MyoD appears to be related to fusion and terminal differentiation of the muscle cell.

Myogenic Regulatory Factor 5 [M0166357]
A SKELETAL MUSCLE-specific transcription factor that contains a basic HELIX-LOOP-HELIX MOTIF. It plays an essential role in MUSCLE DEVELOPMENT.

Myogenic Regulatory Factors [M0027189]
A family of muscle-specific transcription factors which bind to DNA in control regions and thus regulate myogenesis. All members of this family contain a conserved helix-loop-helix motif which is homologous to the myc family proteins. These factors are only found in skeletal muscle. Members include the myoD protein (MYOD PROTEIN); MYOGENIN; myf-5, and myf-6 (also called MRF4 or herculin).

Myogenin [M0027190]
A myogenic regulatory factor that controls myogenesis. Myogenin is induced during differentiation of every skeletal muscle cell line that has been investigated, in contrast to the other myogenic regulatory factors that only appear in certain cell types.

Myoglobin [M0014352]
A conjugated protein which is the oxygen-transporting pigment of muscle. It is made up of one globin polypeptide chain and one heme group.

Myosin Essential Light Chains [M0028367]

Myosin Heavy Chains [M0028369]
The larger subunits of MYOSINS. The heavy chains have a molecular weight of about 230 kDa and each heavy chain is usually associated with a dissimilar pair of MYOSIN LIGHT CHAINS.

Myosin IA [M0014363]

Myosin IB [M0014364]

Myosin Light Chains [M0028368]
The smaller subunits of MYOSINS that bind near the head groups of MYOSIN HEAVY CHAINS. The myosin light chains have a molecular weight of about 20 KDa and there are usually one essential and one regulatory pair of light chains associated with each heavy chain. Many myosin light chains that bind calcium are considered "calmodulin-like" proteins.

Myosin Regulatory Light Chain [M0371890]

Myosin Subfragments [M0024319]
Parts of the myosin molecule resulting from cleavage by proteolytic enzymes (PAPAIN; TRYPSIN; or CHYMOTRYPSIN) at well-localized regions. Study of these isolated fragments helps to delineate the functional roles of different parts of myosin. Two of the most common subfragments are myosin S-1 and myosin S-2. S-1 contains the heads of the heavy chains plus the light chains and S-2 contains part of the double-stranded, alpha-helical, heavy chain tail (myosin rod).

Myosin Type I [M0014366]
A subclass of myosins found generally associated with actin-rich membrane structures such as filopodia. Members of the myosin type I family are ubiquitously expressed in eukaryotes. The heavy chains of myosin type I lack coiled-coil forming sequences in their tails and therefore do not dimerize.

Myosin Type II [M0014365]
The subfamily of myosin proteins that are commonly found in muscle fibers. Myosin II is also involved a diverse array of cellular functions including cell division, transport within the GOLGI APPARATUS, and maintaining MICROVILLI structure.

Myosin Type III [M0373693]
A subclass of myosins originally found in the photoreceptor of DROSOPHILA. The heavy chains can occur as two alternatively spliced isoforms of 132 and 174 KDa. The amino terminal of myosin type III is highly unusual in that it contains a protein kinase domain which may be an important component of the visual process.

Myosin Type IV [M0373712]
A subclass of myosin found in ACANTHAMOEBA. It is a non-filamentous myosin containing a single 180-kDa myosin heavy chain.

Myosin Type V [M0211221]
A subclass of myosin involved in organelle transport and membrane targeting. It is abundantly found in nervous tissue and neurosecretory cells. The heavy chains of myosin V contain unusually long neck domains that are believed to aid in translocating molecules over large distances.

Myosin-Light-Chain Kinase [M0014367]
An enzyme that phosphorylates myosin light chains in the presence of ATP to yield myosin-light chain phosphate and ADP, and requires calcium and calmodulin. The 20-kDa light chain is phosphorylated more rapidly than any other acceptor, but light chains from other myosins and myosin itself can act as acceptors. The enzyme plays a central role in the regulation of smooth muscle contraction.

Myosin-Light-Chain Phosphatase [M0079054]
A phosphoprotein phosphatase that is specific for MYOSIN LIGHT CHAINS. It is composed of three subunits, which include a catalytic subunit, a myosin binding subunit, and a third subunit of unknown function.

Myosin-V p190 [M0211222]

Myosins [M0014361]
A diverse superfamily of proteins that function as translocating proteins. They share the common characteristics of being able to bind ACTINS and hydrolyse MgATP. Myosins generally consist of heavy chains which are involved in locomotion, and light chains which are involved in regulation. Within the structure of myosin heavy chain are three domains: the head, the neck and the tail. The head region of the heavy chain contains the actin binding domain and MgATPase domain which provides energy for locomotion. The neck region is involved in binding the light-chains. The tail region provides the anchoring point that maintains the position of the heavy chain. The superfamily of myosins is organized into structural classes based upon the type and arrangement of the subunits they contain.

Myristoyl-ACP [M0000331]

N-Acetylgalactosamine-4-Sulfatase [M0029765]
An arylsulfatase that catalyzes the hydrolysis of the 4-sulfate groups of the N-acetyl-D-galactosamine 4-sulfate units of chondroitin sulfate and dermatan sulfate. A deficiency of this enzyme is responsible for the inherited lysosomal disease, Maroteaux-Lamy syndrome (MUCOPOLYSACCHARIDOSIS VI). EC 3.1.6.12.

N-Acetylgalactosaminyltransferases [M0026343]
Enzymes that catalyze the transfer of N-acetylgalactosamine from a nucleoside diphosphate N-acetylgalactosamine to an acceptor molecule which is frequently another carbohydrate. EC 2.4.1.-.

N-Acetylglucosamine beta-D-Galactosyltransferase [M0014390]

N-Acetylglucosaminyltransferases [M0026344]
Enzymes that catalyze the transfer of N-acetylglucosamine from a nucleoside diphosphate N-acetylglucosamine to an acceptor molecule which is frequently another carbohydrate. EC 2.4.1.-.

N-Acetylgucosamide 1-4 beta Galactosyl Transferase [M0012182]

N-Acetylhexosaminyltransferases [M0026342]
Enzymes that catalyze the transfer of N-acetylhexosaminyl groups to an acceptor molecule which is frequently another carbohydrate. EC 2.4.1.

N-Acetyllactosamine Synthase [M0014389]
The A protein of the lactose synthase complex. In the presence of the B protein (LACTALBUMIN) specificity is changed from N-acetylglucosamine to glucose. EC 2.4.1.90.

N-Acetylmuramoyl-L-alanine Amidase [M0014392]
An autolytic enzyme bound to the surface of bacterial cell walls. It catalyzes the hydrolysis of the link between N-acetylmuramoyl residues and L-amino acid residues in certain cell wall glycopeptides, particularly peptidoglycan. EC 3.5.1.28.

N-Actin [M0456010]

N-Acylneuraminate Cytidylyltransferase [M0000334]
An enzyme that forms CMP-acylneuraminic acids, which donate the N-acylneuraminic acid residues to the terminal sugar residue of a ganglioside or glycoprotein. EC 2.7.7.43.

N-Acylsphingosine Galactosyltransferase [M0080284]
An enzyme that catalyzes the conversion of UDP-galactose and N-acylsphingosine to D-galactosylceramide and UDP.

N-alpha-Benzoyl-DL-arginine-4-nitroanilide [M0002378]

N-Bak Protein [M0478941]
An isoform of Bak protein containing only the N-terminal BH3 domain. N-Bak promotes neuronal apoptosis.

N-Cadherins [M0024236]

N-Ethylmaleimide-Sensitive Proteins [M0166470]
ATPases that are members of the AAA protein superfamily (ATPase family Associated with various cellular Activities). The NSFs functions, acting in conjunction with SOLUBLE NSF ATTACHMENT PROTEINS (i.e. SNAPs, which have no relation to SNAP 25), are to dissociate SNARE complexes.

N-Formylmethionine [M0014395]
Effective in the initiation of protein synthesis. The initiating methionine residue enters the ribosome as N-formylmethionyl tRNA. This process occurs in Escherichia coli and other bacteria as well as in the mitochondria of eucaryotic cells.

N-Formylmethionine Leucyl-Phenylalanine [M0014396]
N-Formylmethionyl-leucyl-phenylalanine. A formylated tripeptide originally isolated from bacterial filtrates that is positively chemotactic to polymorphonuclear leucocytes, and causes them to release lysosomal enzymes and become metabolically activated.

N-Glycosyl Hydrolases [M0403889]
A class of enzymes involved in the hydrolysis of the N-glycosidic bond of nitrogen-linked sugars.

N-Methyl-D-aspartic Acid [M0024737]

N-Methylaspartate [M0024738]
An amino acid that, as the D-isomer, is the defining agonist for the NMDA receptor subtype of glutamate receptors (RECEPTORS, NMDA).

N-myc Proteins [M0024866]

N-substituted Glycines [M0289359]
AMINO ACIDS composed of GLYCINE substituted at the nitrogen rather than the usual carbon position, resulting in the loss of HYDROGEN BONDING donors. Polymers of these compounds are called PEPTOIDS.

N-Terminal Peptide of POMC (NPP) [M0095649]

Na(+)-K(+)-Exchanging ATPase [M0000394]
An enzyme that catalyzes the active transport system of sodium and potassium ions across the cell wall. Sodium and potassium ions are closely coupled with membrane ATPase which undergoes phosphorylation and dephosphorylation, thereby providing energy for transport of these ions against concentration gradients. EC 3.6.1.37.

NAD(P) Nucleosidase [M0077251]

NAD(P)(+)-Arginine ADP-Ribosyltransferase [M0023658]
An enzyme that catalyzes the transfer of the ADP-ribose moiety from NAD+ or NADP+ to specific protein substrates with arginine, arginine-type compounds, agmatine, or guanidine as acceptors. This mono-ADP-ribosylation reaction is the mechanism of action common to several bacterial toxins affecting profound changes in cellular metabolism, such as activation of adenylate cyclase, regulation of protein synthesis at the level of elongation factor 2, and ion transport across biological membranes.

NAD(P)H Dehydrogenase (Quinone) [M0025387]
A flavoprotein that reversibly catalyzes the oxidation of NADH or NADPH by various quinones and oxidation-reduction dyes. The enzyme is inhibited by dicoumarol, capsaicin, and caffeine. EC 1.6.99.2.

NAD(P)H Nitroblue Tetrazolium Reductase [M0014408]

NAD+ ADP-Ribosyltransferase [M0415110]
An enzyme that catalyze the transfer of ADP-RIBOSE from NAD+ to an amino acid residue in a specific protein substrate. This reaction is catalyzed by both mono(ADP-ribose) transferases as well as POLY(ADP-RIBOSE) POLYMERASES. When the term NAD+ ADP-Ribosyltransferase refers to EC 2.4.2.30 it is referring to POLY(ADP-RIBOSE) POLYMERASES.

NAD+ Nucleosidase [M0014405]
An enzyme that catalyzes the hydrolysis of nicotinamide adenine dinucleotide (NAD) to NICOTINAMIDE and ADENOSINE DIPHOSPHATE RIBOSE. Some are extracellular (ectoenzymes).The enzyme from some sources also catalyses the hydrolysis of nicotinamide adenine dinucleotide phosphate (NADP).

NAD-Dependent Protein Deacetylases [M0417189]
Enzymes that deacetylate proteins by catalyzing the formation of O-acetyl-ADP-ribose from the ADP-RIBOSE moiety (of NAD) and the acetyl group that is being removed from the protein.

NADH Dehydrogenase [M0014406]
A flavoprotein and iron sulfur-containing oxidoreductase that catalyzes the oxidation of NADH to NAD. In eukaryotes the enzyme can be found as a component of mitochondrial electron transport complex I. Under experimental conditions the enzyme can use CYTOCHROME C GROUP as the reducing cofactor. The enzyme was formerly listed as EC 1.6.2.1.

NADH Dehydrogenase (Ubiquinone) [M0447491]

NADH Tetrazolium Reductase [M0014409]
Catalyzes the reduction of tetrazolium compounds in the presence of NADH.

NADH, NADPH Oxidoreductases [M0014410]
A group of oxidoreductases that act on NADH or NADPH. In general, enzymes using NADH or NADPH to reduce a substrate are classified according to the reverse reaction, in which NAD+ or NADP+ is formally regarded as an acceptor. This subclass includes only those enzymes in which some other redox carrier is the acceptor. (Enzyme Nomenclature, 1992, p100) EC 1.6.

NADP Transhydrogenase [M0014414]
An enzyme present in the mitochondrial membrane of animals and in microorganisms. In the presence of energy (ATP) it catalyzes reversibly the reduction of NAD by NADPH to yield NADP and NADH. This reaction permits the utilization of the reducing properties of NADPH by the respiratory chain and in the reverse direction it allows the reduction of NADP for biosynthetic purposes. EC 1.6.1.1.

NADPH Dehydrogenase [M0014416]
A flavoprotein that reversibly oxidizes NADPH to NADP and a reduced acceptor. EC 1.6.99.1.

NADPH Oxidase [M0028676]
A flavoprotein enzyme that catalyzes the univalent reduction of OXYGEN using NADPH as an electron donor to create SUPEROXIDE ANION. The enzyme is dependent on a variety of CYTOCHROMES. Defects in the production of superoxide ions by enzymes such as NADPH oxidase result in GRANULOMATOUS DISEASE, CHRONIC.

NADPH-Ferrihemoprotein Reductase [M0014415]
A flavoprotein that catalyzes the reduction of heme-thiolate-dependent monooxygenases and is part of the microsomal hydroxylating system. EC 1.6.2.4.

Nafarelin [M0026219]
A potent synthetic agonist of GONADOTROPIN-RELEASING HORMONE with 3-(2-naphthyl)-D-alanine substitution at residue 6. Nafarelin has been used in the treatments of central PRECOCIOUS PUBERTY and ENDOMETRIOSIS.

Nafarelin Acetate [M0329373]

Nafarelin Monoacetate [M0329372]

Nanotubes, Peptide [M0447787]
NANOTUBES formed from cyclic peptides (PEPTIDES, CYCLIC). Alternating D and L linkages create planar rings that self assemble by stacking into nanotubes. They can form pores through CELL MEMBRANE causing damage to cells.

Naphthol AS D Esterase [M0014461]
Hydrolytic enzyme activity used as a histocytochemical test for the presence of esterases in tissue. Substrate used is 3-hydroxy-4'-nitro-2-naphthanilide chloroacetate (naphthol AS-D).

NasBI Endonuclease [M0023452]

Natrecor [M0446698]

Natriuretic Peptide, Brain [M0029829]
A PEPTIDE that is secreted by the BRAIN and the HEART ATRIA, stored mainly in cardiac ventricular MYOCARDIUM. It can cause NATRIURESIS; DIURESIS; VASODILATION; and inhibits secretion of RENIN and ALDOSTERONE. It improves heart function. It contains 32 AMINO ACIDS.

Natriuretic Peptide, C-Type [M0029831]
A PEPTIDE of 22 amino acids, derived mainly from cells of VASCULAR ENDOTHELIUM. It is also found in the BRAIN, major endocrine glands, and other tissues. It shares structural homology with ATRIAL NATRIURETIC FACTOR. It has vasorelaxant activity thus is important in the regulation of vascular tone and blood flow. Several high molecular weight forms containing the 22 amino acids have been identified.

Natriuretic Peptides [M0447624]
Peptides that regulate the WATER-ELECTROLYTE BALANCE in the body, also known as natriuretic peptide hormones. Several have been sequenced (ATRIAL NATRIURETIC FACTOR; BRAIN NATRIURETIC PEPTIDE; C-TYPE NATRIURETIC PEPTIDE).

nef Protein [M0024070]

Neoglycoproteins [M0009494]

Neomycin Phosphotransferase II [M0029496]

Neoplasm Proteins [M0014578]
Proteins whose abnormal expression (gain or loss) are associated with the development, growth, or progression of NEOPLASMS. Some neoplasm proteins are tumor antigens (ANTIGENS, NEOPLASM), i.e. they induce an immune reaction to their tumor. Many neoplasm proteins have been characterized and are used as tumor markers (TUMOR MARKERS, BIOLOGICAL) when they are detectable in cells and body fluids as monitors for the presence or growth of tumors. Abnormal expression of ONCOGENE PROTEINS is involved in neoplastic transformation, whereas the loss of expression of TUMOR SUPPRESSOR PROTEINS is involved with the loss of growth control and progression of the neoplasm.

Neoral [M0025284]

Neoton [M0016658]

Neprilysin [M0023500]
Enzyme that is a major constituent of kidney brush-border membranes and is also present to a lesser degree in the brain and other tissues. It preferentially catalyzes cleavage at the amino group of hydrophobic residues of the B-chain of insulin as well as opioid peptides and other biologically active peptides. The enzyme is inhibited primarily by EDTA, phosphoramidon, and thiorphan and is reactivated by zinc. Neprilysin is identical to common acute lymphoblastic leukemia antigen (CALLA Antigen), an important marker in the diagnosis of human acute lymphocytic leukemia. There is no relationship with CALLA PLANT.

Nerve Growth Factor [M0328210]
NERVE GROWTH FACTOR is the first of a series of neurotrophic factors that were found to influence the growth and differentiation of sympathetic and sensory neurons. It is comprised of alpha, beta, and gamma subunits. The beta subunit is responsible for its growth stimulating activity.

Nerve Growth Factor 2 [M0014656]

Nerve Growth Factor alpha Subunit [M0331883]

Nerve Growth Factor beta Subunit [M0014654]

Nerve Growth Factor gamma Subunit [M0331885]

Nerve Growth Factors [M0014655]
Factors which enhance the growth potentialities of sensory and sympathetic nerve cells.

Nerve Tissue Proteins [M0014664]

Nervous System-Specific Enolase [M0016710]

Netropsin [M0014675]
A basic polypeptide isolated from Streptomyces netropsis. It is cytotoxic and its strong, specific binding to A-T areas of DNA is useful to genetics research.

Netropsin Hydrochloride [M0329940]

neu Differentiation Factor [M0137305]

Neupogen [M0373311]

Neural Cell Adhesion Molecule L1 [M0122500]
A member of the immunoglobulin superfamily of neuronal cell adhesion molecules that is required for proper nervous system development. Neural cell adhesion molecule L1 consists of six Ig domains, five fibronectin domains, a transmembrane region and an intracellular domain. Two splicing variants are known: a neuronal form that contains a four-amino acid RSLE sequence in the cytoplasmic domain, and a non-neuronal form that lacks the RSLE sequence. Mutations in the L1 gene result in L1 disease. Neural cell adhesion molecule L1 is predominantly expressed during development in neurons and Schwann cells; involved in cell adhesion, neuronal migration, axonal growth and pathfinding, and myelination.

Neural Cell Adhesion Molecules [M0028384]
Cell adhesion molecule involved in a diverse range of contact-mediated interactions among neurons, astrocytes, oligodendrocytes, and myotubes. It is widely but transiently expressed in many tissues early in embryogenesis. Four main isoforms exist, including CD56; (ANTIGENS, CD56); but there are many other variants resulting from alternative splicing and post-translational modifications. (From Pigott & Power, The Adhesion Molecule FactsBook, 1993, pp115-119)

Neuraminidase [M0014689]
An enzyme that catalyzes the hydrolysis of alpha-2,3, alpha-2,6-, and alpha-2,8-glycosidic linkages (at a decreasing rate, respectively) of terminal sialic residues in oligosaccharides, glycoproteins, glycolipids, colominic acid, and synthetic substrate. (From Enzyme Nomenclature, 1992) EC 3.2.1.18.

Neuregulins [M0328213]
A family of peptides originally found as factors that stimulate the phosphorylation of the erbB-2 receptor (RECEPTORS, ERBB-2). Multiple variant forms of NEUREGULINS occur due to alternative splicing of their mRNAs. The NEUREGULINS include products from the three known genes (NGR1; NGR2 and NGR3).

Neurite Outgrowth Factors [M0014652]

Neuritogenic Protein [M0007364]

Neurocalcin [M0201985]
A neuronal calcium sensor protein that is expressed as several isoforms and can interact with ACTIN; TUBULIN; and CLATHRIN.

Neurocalcin alpha [M0453568]

Neurocalcin delta [M0391373]

Neuroendocrine Secretory Protein 7B2 [M0136553]
An acidic protein found in the NEUROENDOCRINE SYSTEM that functions as a molecular chaperone for PROPROTEIN CONVERTASE 2.

Neurofibromin 1 [M0179586]
A protein found most abundantly in the nervous system. Defects or deficiencies in this protein are associated with NEUROFIBROMATOSIS 1, Watson syndrome, and LEOPARD syndrome. Mutations in the gene (GENE, NEUROFIBROMATOSIS 1) affect two known functions: regulation of ras-GTPase and tumor suppression.

Neurofibromin 2 [M0217356]
A membrane protein homologous to the ERM (Ezrin-Radixin-Moesin) family of cytoskeleton-associated proteins which regulate physical properties of membranes. Alterations in neurofibromin 2 are the cause of NEUROFIBROMATOSIS 2.

Neurofilament Proteins [M0025716]
Type III intermediate filament proteins that assemble into neurofilaments, the major cytoskeletal element in nerve axons and dendrites. They consist of three distinct polypeptides, the neurofilament triplet. Types I, II, and IV intermediate filament proteins form other cytoskeletal elements such as keratins and lamins. It appears that the metabolism of neurofilaments is disturbed in Alzheimer's disease, as indicated by the presence of neurofilament epitopes in the neurofibrillary tangles, as well as by the severe reduction of the expression of the gene for the light neurofilament subunit of the neurofilament triplet in brains of Alzheimer's patients. (Can J Neurol Sci 1990 Aug;17(3):302)

Neurofilament Triplet Proteins [M0025718]

Neurogranin [M0183239]
A BRAIN-specific substrate for PROTEIN KINASE C that binds CALMODULIN and is involved in regulation of CALCIUM SIGNALING.

Neurokinin A [M0023535]
A mammalian neuropeptide of 10 amino acids that belongs to the tachykinin family. It is similar in structure and action to SUBSTANCE P and NEUROKININ B with the ability to excite neurons, dilate blood vessels, and contract smooth muscles, such as those in the BRONCHI.

Neurokinin B [M0023534]
A mammalian neuropeptide of 10 amino acids that belongs to the tachykinin family. It is similar in structure and action to SUBSTANCE P and NEUROKININ A with the ability to excite neurons, dilate blood vessels, and contract smooth muscles, such as those in the URINARY BLADDER and UTERUS.

Neuroleukin [M0024175]
Neuronal growth factor and lymphokine product of lectin-stimulated T-cells which induces immunoglobulin secretion. Its amino acid sequence is partially homologous to the HIV envelope glycoprotein gp120, which may explain, in part, the pathogenesis of AIDS DEMENTIA COMPLEX. Closely related to PHOSPHOHEXOSE ISOMERASE; AUTOCRINE MOTILITY FACTOR and maturation factor.

Neurolin [M0030061]

Neuromodulator Receptor [M0027155]

Neuron-Specific Enolase [M0016711]

Neuronal Apoptosis-Inhibitory Protein [M0241452]
An inhibitor of apoptosis protein that was initially identified during analysis of CHROMOSOME DELETIONS associated with SPINAL MUSCULAR ATROPHY. Naip contains a nucleotide binding oligomerization domain and a carboxy-terminal LEUCINE rich repeat.

Neuronal Calcium-Sensor Proteins [M0481045]
A family of intracellular calcium-sensing proteins found predominately in NEURONS and PHOTORECEPTORS. They contain EF HAND MOTIFS and undergo conformational changes upon calcium-binding. Neuronal calcium-sensor proteins interact with other regulatory proteins to mediate physiological responses to a change in intracellular calcium concentration.

Neuronal Differentiation Factor, Cholinergic [M0137315]

Neuropeptide Y [M0014746]
A 36-amino acid peptide present in many organs and in many sympathetic noradrenergic neurons. It has vasoconstrictor and natriuretic activity and regulates local blood flow, glandular secretion, and smooth muscle activity. The peptide also stimulates feeding and drinking behavior and influences secretion of pituitary hormones.

Neuropeptide Y Like Immunoreactive Peptide [M0014747]

Neuropeptides [M0014748]
Peptides released by NEURONS as intercellular messengers. Many neuropeptides are also hormones released by non-neuronal cells.

Neurophilins [M0057218]
Immunophilins found in the brain.

Neurophysin I [M0014750]

Neurophysin II [M0014751]

Neurophysin III [M0014752]

Neurophysins [M0014753]
Carrier proteins for OXYTOCIN and VASOPRESSIN. They are polypeptides of about 10-kDa, synthesized in the HYPOTHALAMUS. Neurophysin I is associated with oxytocin and neurophysin II is associated with vasopressin in their respective precursors and during transportation down the axons to the neurohypophysis (PITUITARY GLAND, POSTERIOR).

Neuropilin-1 [M0191842]
Dimeric cell surface receptor involved in angiogenesis (NEOVASCULARIZATION, PHYSIOLOGICAL) and axonal guidance. Neuropilin-1 is a 140-kDa transmembrane protein that binds CLASS 3 SEMAPHORINS, and several other growth factors. Neuropilin-1 forms complexes with plexins or VEGF RECEPTORS, and binding affinity and specificity are determined by the composition of the neuropilin dimer and the identity of other receptors complexed with it. Neuropilin-1 is expressed in distinct patterns during neural development, complementary to those described for NEUROPILIN-2.

Neuropilin-2 [M0377884]
Transmembrane receptor for CLASS 3 SEMAPHORINS and several vascular endothelial growth factor isoforms. Neuropilin-2 functions either as a homodimer or as a heterodimer with NEUROPILIN-1. The binding affinity of neuropilin-2 varies for different class 3 semaphorin isoforms and is dependent on the composition of the dimer. The protein also forms receptor complexes with plexins and with VEGF RECEPTORS, which alters the binding characteristics of the receptor.

Neuropilins [M0191838]
Neuropilins are 140-kDa vertebrate cell surface receptors that bind neuronal guidance molecules during neural development and axonal outgrowth, and modulate VEGF-mediated angiogenesis. NEUROPILIN-1 and NEUROPILIN-2 differ in their binding specificities, and are distributed complementarily in regions of the developing nervous system. Neuropilins are receptors for secreted CLASS 3 SEMAPHORINS as well as for vascular endothelial growth factors, and may form hetero- or homodimers. They may also interact synergistically with plexins and with VEGF RECEPTORS to form receptor complexes with distinct affinities and specificities. Neuropilin binding specificity is determined by CUB and coagulation-factor-like domains in the extracellular portion of the molecule, while a MAM domain is essential for SIGNAL TRANSDUCTION.

Neurospora Endonuclease [M0024102]

Neurospora Nuclease [M0024103]

Neurotensin [M0014773]
A biologically active tridecapeptide isolated from the hypothalamus. It has been shown to induce hypotension in the rat, to stimulate contraction of guinea pig ileum and rat uterus, and to cause relaxation of rat duodenum. There is also evidence that it acts as both a peripheral and a central nervous system neurotransmitter.

Neurotransmitter Transport Proteins [M0475593]
Membrane transport proteins found predominately in NEURONS and neuroendocrine cells that facilitate neurotransmitter transport. They include two distinct families of proteins that transport NEUROTRANSMITTERS across the PLASMA MEMBRANE and that transport NEUROTRANSMITTERS into SECRETORY VESICLES.

Neurotrophin 3 [M0328215]
A neurotrophic factor involved in regulating the survival of visceral and proprioceptive sensory neurons. It is closely homologous to nerve growth factor beta and BRAIN-DERIVED NEUROTROPHIC FACTOR.

Neurturin [M0268299]
A glial cell line-derived neurotrophic factor ligand that is specific for the GFRA2 RECEPTOR. Neurturin is essential for the development of specific postganglionic parasympathetic NEURONS.

Neutral alpha-Glucosidase [M0000795]

Neutral Thiol Proteinase [M0005544]

Neutrophil Elastase Inhibitors [M0485530]

NF-E2 Transcription Factor [M0166789]
A basic-leucine zipper transcription factor that regulates GLOBIN gene expression and is related to TRANSCRIPTION FACTOR AP-1. NF-E2 consists of a small MAF protein subunit and a tissue-restricted 45 kDa subunit.

NF-E2 Transcription Factor, p45 Subunit [M0478886]
A tissue-specific subunit of NF-E2 transcription factor that interacts with small MAF PROTEINS to regulate gene expression. P45 NF-E2 protein is expressed primarily in MEGAKARYOCYTES; ERYTHROID CELLS; and MAST CELLS.

NF-E2-Related Factor 1 [M0224528]
A basic-leucine zipper transcription factor that is involved in regulating inflammatory responses, MORPHOGENESIS, and HEME biosynthesis.

NF-E2-Related Factor 2 [M0237441]
A basic-leucine zipper transcription factor that was originally described as a transcriptional regulator controlling expression of the BETA-GLOBIN gene. It may regulate the expression of a wide variety of genes that play a role in protecting cells from oxidative damage.

NF-kappa B [M0024955]
Ubiquitous, inducible, nuclear transcriptional activator that binds to enhancer elements in many different cell types and is activated by pathogenic stimuli. The NF-kappa B complex is a heterodimer composed of two DNA-binding subunits: NF-kappa B1 and relA.

NF-kappa B p100 Precursor Protein [M0212377]
NF-kappa B p100 precursor protein helps retain TRANSCRIPTION FACTOR RELB in the CYTOPLASM and its full-length form inhibits NF-kappa B signaling. It is processed by the PROTEASOME to produce NF-kappa B p52 subunit.

NF-kappa B p105 Precursor Protein [M0198807]
NF-kappa B p105 precursor protein is constitutively processed by the PROTEASOME to produce NF-kappa B p50 subunit. It helps regulate map kinase signaling through its association with Map3k8 protein.

NF-kappa B p50 Subunit [M0195386]
A component of NF-kappa B transcription factor. It is proteolytically processed from NF-kappa B p105 precursor protein and is capable of forming dimeric complexes with itself or with TRANSCRIPTION FACTOR RELA. It regulates expression of GENES involved in immune and inflammatory responses.

NF-kappa B p52 Subunit [M0350347]
A component of NF-kappa B transcription factor. It is proteolytically processed from NF-kappa B p100 precursor protein and is important for maturation of B-LYMPHOCYTES and adaptive HUMORAL IMMUNITY.

NFAT Transcription Factor 1 [M0212776]

NFAT Transcription Factor 2 [M0328766]

NFAT Transcription Factor 3 [M0212771]

NFAT Transcription Factor 4 [M0212772]

NFAT Transcription Factor 5 [M0361472]
A signal-dependent transcription factor that controls cellular response to osmotic stress. NFAT5 is closely related to NFATC PROTEINS but resides constitutively in the CELL NUCLEUS and operates independently of CALCINEURIN and TRANSCRIPTION FACTOR AP-1.

NFATC Transcription Factors [M0212783]
A family of transcription factors characterized by the presence of highly conserved calcineurin- and DNA-binding domains. NFAT proteins are activated in the CYTOPLASM by the calcium-dependent phosphatase CALCINEURIN. They transduce calcium signals to the nucleus where they can interact with TRANSCRIPTION FACTOR AP-1 or NF-KAPPA B and initiate GENETIC TRANSCRIPTION of GENES involved in CELL DIFFERENTIATION and development. NFAT proteins stimulate T-CELL activation through the induction of IMMEDIATE-EARLY GENES such as INTERLEUKIN-2.

NFI Transcription Factors [M0124266]
Transcription factors that were originally identified as site-specific DNA-binding proteins essential for DNA REPLICATION by ADENOVIRUSES. They play important roles in MAMMARY GLAND function and development.

NG-Nitroarginine Methyl Ester [M0028779]
A non-selective inhibitor of nitric oxide synthase. It has been used experimentally to induce hypertension.

NG-Nitroarginine Methyl Ester, D-Orn-Isomer [M0329191]

NG-Nitroarginine Methyl Ester, L-Orn-Isomer, Monohydrochloride [M0329192]

Ni(II)-Aspartate Transcarbamoylase [M0001829]

Nickase [M0006010]

Nicotinamidase [M0014832]
An enzyme that catalyzes the hydrolysis of nicotinamide to nicotinate and ammonia. EC 3.5.1.19.

Nicotinamide N-Methyltransferase [M0111649]
An enzyme found primarily in the LIVER that catalyzes the N-methylation of NICOTINAMIDE and other structurally related compounds.

Nicotinamide Riboside Phosphorylase [M0018165]

Nicotinamide-Nucleotide Adenylyltransferase [M0014930]
An enzyme that catalyzes reversibly the transfer of the adenylyl moiety of ATP to the phosphoryl group of NMN to form NAD+ and pyrophosphate. The enzyme is found predominantly in the nuclei and catalyzes the final reaction in the major pathway for the biosynthesis of NAD in mammals. EC 2.7.7.1.

Niddamycin Polyketide Synthase [M0171387]

Nisin [M0014869]
A 34-amino acid polypeptide antibiotic produced by Streptococcus lactis. It has been used as a food preservative in canned fruits and vegetables, and cheese.

Nitrate Reductase [M0127716]
An enzyme that catalyzes the oxidation of nitrite to nitrate. It is a cytochrome protein that contains IRON and MOLYBDENUM.

Nitrate Reductase (NAD(P)H) [M0094704]
An iron-sulfur and MOLYBDENUM containing FLAVOPROTEIN that catalyzes the oxidation of nitrite to nitrate. This enzyme can use either NAD or NADP as cofactors. It is a key enzyme that is involved in the first step of nitrate assimilation in PLANTS; FUNGI; and BACTERIA. This enzyme was formerly classified as EC 1.6.6.2.

Nitrate Reductase (NADH) [M0101457]
An NAD-dependent enzyme that catalyzes the oxidation of nitrite to nitrate. It is a FLAVOPROTEIN that contains IRON and MOLYBDENUM and is involved in the first step of nitrate assimilation in PLANTS; FUNGI; and BACTERIA. It was formerly classified as EC 1.6.6.1.

Nitrate Reductase (NADPH) [M0122118]
An enzyme that catalyzes the oxidation of nitrite to nitrate in the presence of NADP+. It is a FLAVOPROTEIN that contains IRON and MOLYBDENUM. This enzyme was formerly classified as EC 1.6.6.3 and should not be confused with the enzyme NITRATE REDUCTASE (NAD(P)H).

Nitrate Reductases [M0014873]
Oxidoreductases that are specific for the reduction of NITRATES.

Nitric Oxide Synthase [M0028375]
An NADPH-dependent enzyme that catalyzes the conversion of L-ARGININE and OXYGEN to produce CITRULLINE and NITRIC OXIDE.

Nitric Oxide Synthase Type I [M0284729]
A CALCIUM-dependent, constitutively-expressed form of nitric acid synthase found primarily in NERVE TISSUE.

Nitric Oxide Synthase Type II [M0284733]
A CALCIUM-independent subtype of nitric oxide synthase that may play a role in immune function. It is an inducible enzyme whose expression is transcriptionally regulated by a variety of CYTOKINES.

Nitric Oxide Synthase Type III [M0284725]
A CALCIUM-dependent, constitutively-expressed form of nitric acid synthase found primarily in ENDOTHELIAL CELLS.

Nitrite Reductase (NAD(P)H) [M0100880]
An enzyme found primarily in BACTERIA and FUNGI that catalyzes the oxidation of AMMONIUM HYDROXIDE to nitrite. It is an iron-sulfur HEME; FLAVOPROTEIN containing SIROHEME and can utilize both NAD and NADP as cofactors. This enzyme was formerly classified as EC 1.6.6.4.

Nitrite Reductases [M0014883]
A group of enzymes that oxidize diverse nitrogenous substances to yield nitrite. (Enzyme Nomenclature, 1992) EC 1.

Nitroanisole O-Demethylase [M0014886]
Oxidative enzyme which transforms p-nitroanisole into p-nitrophenol.

Nitrogenase [M0014904]
An enzyme system that catalyzes the fixing of nitrogen in soil bacteria and blue-green algae (CYANOBACTERIA). EC 1.18.6.1.

Nitrogenous Group Transferases [M0029525]
Enzymes that catalyze the transfer of nitrogenous groups, primarily amino groups, from a donor, generally an amino acid, to an acceptor, usually a 2-oxoacid. EC 2.6.

Nitrophenyl Phosphatase [M0014914]

Nitroreductases [M0014919]
Enzymes which reduce nitro groups (NITRO COMPOUNDS) and other nitrogenous compounds.

NK-631 [M0357323]

Nocutil [M0492526]

NOD Leucine-Rich Repeat Proteins [M0493384]
Nod signaling adaptor proteins that contain leucine-rich repeat domains.

Nod Signaling Adaptor Proteins [M0493381]
Cytosolic signaling adaptor proteins that were initially discovered by their role in the innate immunity (IMMUNITY, INNATE) response of organisms that lack an adaptive immune system. This class of proteins contains three domains, a C-terminal ligand recognition domain, an N-terminal effector-binding domain, and a centrally located nuclear-binding oligomerization domain. Many members of this class contain a C-terminal leucine rich domain which binds to PEPTIDOGLYCAN on the surface of BACTERIA and plays a role in pathogen resistance.

Nod1 Signaling Adaptor Protein [M0493409]
A NOD-signaling adaptor protein that contains a C-terminal leucine-rich domain which recognizes bacterial PEPTIDOGLYCAN. It signals via an N-terminal caspase recruitment domain that interacts with other CARD SIGNALING ADAPTOR PROTEINS such as RIP SERINE-THEONINE KINASES. It plays a role in the host defense response by signaling the activation of CASPASES and the MAP KINASE SIGNALING SYSTEM.

Nod2 Signaling Adaptor Protein [M0493385]
A NOD signaling adaptor protein that contains two C-terminal leucine-rich domains which recognize bacterial PEPTIDOGLYCAN. It signals via an N-terminal capase recruitment domain that interacts with other CARD SIGNALING ADAPTOR PROTEINS such as RIP SERINE-THEONINE KINASES. The protein plays a role in the host defense response by signaling the activation of CASPASES and the MAP KINASE SIGNALING SYSTEM. Mutations of the gene encoding the nucleotide oligomerization domain 2 protein have been associated with increased susceptibility to CROHN DISEASE.

Non-Fibrillar Collagens [M0369291]
A family of structurally-related short-chain collagens that do not form large fibril bundles.

Non-Histone Chromosomal Phosphoproteins [M0004404]

Non-Neuronal Enolase [M0016712]

Nonheme Iron Proteins [M0028564]
Proteins, usually acting in oxidation-reduction reactions, containing iron but no porphyrin groups. (Lehninger, Principles of Biochemistry, 1993, pG-10)

Nonmuscle Myosin Type IIA [M0370599]
A nonmuscle isoform of myosin type II found predominantly in platelets, lymphocytes, neutrophils and brush border enterocytes.

Nonmuscle Myosin Type IIB [M0014362]
A nonmuscle isoform of myosin type II found predominantly in neuronal tissue.

Nonspecific Phospholipid Transfer proteins [M0069077]

Nonsuppressible Insulin-Like Activity [M0014953]
A blood protein (NSILA) which mimics the biological activity of insulin in serum, but is not suppressed by insulin antibodies. During acid-ethanol extraction of Cohn fraction III, 10% of the activity is found in the supernatant (NSILA-S) and the remaining activity in the precipitate (NSILA-P). The latter is a large molecular compound, much less stable than the soluble fraction. NSILA-S is a more potent growth factor than insulin and exhibits sulfation activity.

Norditropin [M0028845]

Norepinephrine Plasma Membrane Transport Proteins [M0475612]
Sodium chloride-dependent neurotransmitter symporters located primarily on the PLASMA MEMBRANE of noradrenergic neurons. They remove NOREPINEPHRINE from the EXTRACELLULAR SPACE by high affinity reuptake into PRESYNAPTIC TERMINALS. It regulates signal amplitude and duration at noradrenergic synapses and is the target of ADRENERGIC UPTAKE INHIBITORS.

Norepinephrine Receptors [M0018553]

Norisen [M0116088]

Norleucine [M0014987]
An unnatural amino acid that is used experimentally to study protein structure and function. It is structurally similar to METHIONINE, however it does not contain SULFUR.

Norleucine, L-Isomer [M0329988]

Normegon [M0333588]
FSH:LH = 3:1

Nourseothricin [M0370670]

Novo-5 ASA [M0474828]

Novolin [M0011420]

Novothyrox [M0463513]

Nozucar [M0434516]

NSC 1026 [M0351826]

NSC-526417 [M0373523]

NSF ATPase [M0483548]

NSILA-P [M0014954]

NSILA-S [M0014955]

NspSAIV Endonuclease [M0023453]

Nu-Baclo [M0454547]

Nu-Medopa [M0474251]

NUC1 PPAR [M0199107]

Nuclear ADP Ribose Transferases [M0410069]
Nuclear poly(ADP-ribose) polymerases. EC 2.4.2.30

Nuclear Cap Binding Protein Subunit 1, 80-kDa [M0093744]
A 80kD protein that is a compent of the nuclear cap binding protein complex it forms a heterodimer with nuclear cap binding protein subunit 2, 20 kD

Nuclear Cap Binding Protein Subunit 2, 20-kDa [M0093743]
A 20kD protein that is a component of the nuclear cap binding protein complex it forms a heterodimer with nuclear cap binding protein subunit 2, 80 kD

Nuclear Cap-Binding Protein Complex [M0419050]
A heterodimeric protein complex of RNA cap-binding proteins, which binds with high affinity to the 5' MRNA CAP STRUCTURE in the CELL NUCLEUS. The complex contains two subunits, one of 80-kDa molecular weight and another of 20-kDa molecular weight.

Nuclear Factor 45 Protein [M0212780]
A protein subunit that takes part in forming nuclear factor 90 protein complexes.

Nuclear Factor 90 Protein [M0212781]

Nuclear Factor 90 Protein Complex [M0482122]

Nuclear Factor 90 Proteins [M0477737]
A family of double-stranded RNA-binding proteins that are related to NFATC TRANSCRIPTION FACTORS. In addition to binding to RNA, nuclear factor 90 proteins form heterodimeric complexes that regulate GENETIC TRANSCRIPTION and may play a role in T-CELL activation.

Nuclear Factor I-A [M0481955]

Nuclear Factor I-B [M0481956]

Nuclear Factor I-C [M0481957]

Nuclear Factor I-X [M0481958]

Nuclear Matrix Binding Proteins [M0406411]

Nuclear Matrix-Associated Proteins [M0096991]
A broad category of nuclear proteins that are components of or participate in the formation of the NUCLEAR MATRIX.

Nuclear Pore Complex Proteins [M0383353]
Proteins that form the structure of the NUCLEAR PORE. They are involved in active, facilitated and passive transport of molecules in and out of the CELL NUCLEUS.

Nuclear Protein [M0015044]

Nuclear Protein Phosphatase [M0016693]

Nuclear Proteins [M0015042]
Proteins found in the nucleus of a cell. Do not confuse with NUCLEOPROTEINS which are proteins conjugated with nucleic acids, that are not necessarily present in the nucleus.

Nuclear Receptor Coactivator 2 [M0264546]
A transcription factor that partners with ligand bound GLUCOCORTICOID RECEPTORS and ESTROGEN RECEPTORS to stimulate GENETIC TRANSCRIPTION. It plays an important role in FERTILITY as well as in METABOLISM of LIPIDS.

Nuclear Respiratory Factor 1 [M0479967]
A transcription factor that controls the expression of variety of proteins including CYTOCHROME C and 5-AMINOLEVULINATE SYNTHETASE. It plays an important role in maintenance of the RESPIRATORY CHAIN of MITOCHONDRIA.

Nuclear Respiratory Factors [M0224530]
A family of transcription factors that control expression of a variety of nuclear GENES encoding proteins that function in the RESPIRATORY CHAIN of the MITOCHONDRIA.

Nuclear Trans-Acting Factor [M0023899]

Nuclease P1 [M0024104]

Nucleobase Transport Proteins [M0404022]
Proteins involved in the transport of nucleobases such as PYRIMIDINES and PURINES across membranes.

Nucleobase, Nucleoside, Nucleotide, and Nucleic Acid Transport Proteins [M0404021]
A broad class of proteins involved in the transport of nucleobases, NUCLEOSIDES; NUCLEOTIDES; and NUCLEIC ACIDS; across membranes.

Nucleocapsid [M0028665]
A protein-nucleic acid complex which forms part or all of a virion. It consists of a CAPSID plus enclosed nucleic acid. Depending on the virus, the nucleocapsid may correspond to a naked core or be surrounded by a membranous envelope.

Nucleocapsid Proteins [M0029092]
Viral proteins found in either the NUCLEOCAPSID or the viral core (VIRAL CORE PROTEINS).

Nucleocytoplasmic Transport Proteins [M0384917]
Proteins involved in the process of transporting molecules in and out the cell nucleus. Included here are: NUCLEOPORINS, which are membrane proteins that form the NUCLEAR PORE COMPLEX; KARYOPHERINS, which carry molecules through the nuclear pore complex; and proteins that play a direct role in the transport of karyopherin complexes through the nuclear pore complex.

Nucleolar Proteins [M0015043]

Nucleoproteins [M0015058]
Proteins conjugated with nucleic acids.

Nucleosidases [M0015059]
N-GLYCOSYL HYDROLASES that catalyze the hydrolysis of the N-glycosidic bond of nucleoside-linked sugars.

Nucleoside Deaminases [M0015060]
Catalyze the hydrolysis of nucleosides with the elimination of ammonia.

Nucleoside Transport Proteins [M0404023]
Proteins involved in the transport of NUCLEOSIDES across cellular membranes.

Nucleoside Triphosphate Phosphohydrolase I [M0077324]

Nucleoside Triphosphate Phosphohydrolase II [M0358043]

Nucleoside-Diphosphate Kinase [M0015062]
An enzyme that is found in mitochondria and in the soluble cytoplasm of cells. It catalyzes reversible reactions of a nucleoside triphosphate, e.g., ATP, with a nucleoside diphosphate, e.g., UDP, to form ADP and UTP. Many nucleoside diphosphates can act as acceptor, while many ribo- and deoxyribonucleoside triphosphates can act as donor. EC 2.7.4.6.

Nucleoside-Phosphate Kinase [M0015064]
An enzyme that catalyzes reversible reactions of a nucleoside triphosphate, e.g., ATP, with a nucleoside monophosphate, e.g., UMP, to form ADP and UDP. Many nucleoside monophosphates can act as acceptor while many ribo- and deoxyribonucleoside triphosphates can act as donor. EC 2.7.4.4.

Nucleoside-Triphosphatase [M0077332]
An enzyme which catalyzes the hydrolysis of nucleoside triphosphates to nucleoside diphosphates. It may also catalyze the hydrolysis of nucleotide triphosphates, diphosphates, thiamine diphosphates and FAD. The nucleoside triphosphate phosphohydrolases I and II are subtypes of the enzyme which are found mostly in viruses.

Nucleosomes [M0015068]
The repeating structural units of chromatin, each consisting of approximately 200 base pairs of DNA wound around a protein core. This core is composed of the histones H2A, H2B, H3, and H4.

Nucleotidases [M0015071]
A class of enzymes that catalyze the conversion of a nucleotide and water to a nucleoside and orthophosphate. EC 3.1.3.-.

Nucleotide Deaminases [M0015072]
Catalyze the hydrolysis of nucleotides with the elimination of ammonia.

Nucleotide Transport Proteins [M0404024]
Proteins involved in the transport of NUCLEOTIDES across cellular membranes.

Nucleotidyltransferases [M0015077]
A class of enzymes that transfers nucleotidyl residues. EC 2.7.7.

NutraSweet [M0357396]

Nutropin [M0028847]

O(6)-Methylguanine-DNA Methyltransferase [M0029471]
An enzyme that transfers methyl groups from O(6)-methylguanine, and other methylated moieties of DNA, to a cysteine residue in itself, thus repairing alkylated DNA in a single-step reaction. EC 2.1.1.63.

Octamer Transcription Factor-1 [M0142678]
A ubiquitously expressed octamer transcription factor that regulates GENETIC TRANSCRIPTION of SMALL NUCLEAR RNA; IMMUNOGLOBULIN GENES; and HISTONE H2B genes.

Octamer Transcription Factor-2 [M0478029]
An octamer transcription factor expressed primarily in B-LYMPHOCYTES and the developing CENTRAL NERVOUS SYSTEM that regulates GENETIC TRANSCRIPTION of IMMUNOGLOBULIN GENES.

Octamer Transcription Factor-3 [M0175331]
An octamer transcription factor that is expressed primarily in totipotent embryonic STEM CELLS and GERM CELLS and is down-regulated during CELL DIFFERENTIATION.

Octamer Transcription Factor-6 [M0180567]
An octamer transcription factor that plays an important role in the MYELIN SHEATH development by SCHWANN CELLS.

Octamer Transcription Factors [M0478021]
A family of POU domain factors that bind the octamer motif ATTTGCAT in PROMOTER and ENHANCER regions to regulate GENE EXPRESSION.

Octreotide [M0023526]
A potent, long-acting synthetic SOMATOSTATIN octapeptide analog that inhibits secretion of GROWTH HORMONE and is used to treat hormone-secreting tumors; DIABETES MELLITUS; HYPOTENSION, ORTHOSTATIC; HYPERINSULINISM; hypergastrinemia; and small bowel fistula.

Octreotide Acetate [M0329524]

Ocu-Tracin [M0454534]

OL 27-400 [M0378530]

Olfactory Marker Protein [M0107384]
A ubiquitous, cytoplasmic protein found in mature OLFACTORY RECEPTOR NEURONS of all VERTEBRATES. It is a modulator of the olfactory SIGNAL TRANSDUCTION PATHWAY.

Oligo-1,6-Glucosidase [M0015261]
An enzyme that catalyzes the endohydrolysis of 1,6-alpha-glucosidic linkages in isomaltose and dextrins produced from starch and glycogen by alpha-amylase. EC 3.2.1.10.

Oligopeptides [M0015279]
Peptides composed of between two and twelve amino acids.

omega-Agatoxin IVA [M0328342]
A neuropeptide toxin from the venom of the funnel web spider, Agelenopsis aperta. It inhibits CALCIUM CHANNELS, P-TYPE by altering the voltage-dependent gating so that very large depolarizations are needed for channel opening. It also inhibits CALCIUM CHANNELS, Q-TYPE.

omega-Conotoxin GVIA [M0328343]
A neurotoxic peptide, which is a cleavage product (VIa) of the omega-Conotoxin precursor protein contained in venom from the marine snail, CONUS geographus. It is an antagonist of CALCIUM CHANNELS, N-TYPE.

omega-Conotoxins [M0328344]
A family of structurally related neurotoxic peptides from mollusk venom that inhibit voltage-activated entry of calcium into the presynaptic membrane. They selectively inhibit N-, P-, and Q-type calcium channels.

omega-Crystallins [M0005402]
A type of crystallin that has been found in the lens (LENS, CRYSTALLINE) of certain species of MOLLUSCA such as SQUID and OCTOPUS. It is an inactivated form of aldehyde dehydrogenase.

omega-N-Methylarginine [M0028771]
A competitive inhibitor of nitric oxide synthetase.

Oncogene Protein gp140(v-fms) [M0024883]
Transforming glycoprotein coded by the fms oncogene from the Susan McDonough strain of feline sarcoma virus (SM-FeSV). The oncogene protein v-fms lacks sequences, which, in the highly homologous proto-oncogene protein c-fms (CSF-1 receptor), normally serve to regulate its tyrosine kinase activity. The missing sequences in v-fms mimic the effect of ligand and lead to constitutive cell growth. The protein gp120(v-fms) is post-translationally modified to generate gp140(v-fms).

Oncogene Protein p190(bcr-abl) [M0024528]

Oncogene Protein p21(ras) [M0024065]
Transforming protein encoded by ras oncogenes. Point mutations in the cellular ras gene (c-ras) can also result in a mutant p21 protein that can transform mammalian cells. Oncogene protein p21(ras) has been directly implicated in human neoplasms, perhaps accounting for as much as 15-20% of all human tumors. This enzyme was formerly listed as EC 3.6.1.47.

Oncogene Protein p210(bcr-abl) [M0024529]

Oncogene Protein p37(v-mos) [M0026147]

Oncogene Protein p55(v-myc) [M0024873]
Transforming protein coded by myc oncogenes. The v-myc protein has been found in several replication-defective avian retrovirus isolates which induce a broad spectrum of malignancies.

Oncogene Protein p65(gag-jun) [M0025541]
Transforming protein coded by jun oncogenes (GENES, JUN). This is a gag-onc fusion protein of about 65 kDa derived from avian sarcoma virus. v-jun lacks a negative regulatory domain that regulates transcription in c-jun.

Oncogene Protein pp60(v-src) [M0024064]
A tyrosine-specific protein kinase encoded by the v-src oncogene of Rous sarcoma virus. The transforming activity of pp60(v-src) depends on both the lack of a critical carboxy-terminal tyrosine phosphorylation site at position 527, and the attachment of pp60(v-src) to the plasma membrane which is accomplished by myristylation of its N-terminal glycine.

Oncogene Protein tpr-met [M0023874]
The GENETIC TRANSLATION product from a GENE FUSION between a sequence from the tpr protein gene on the human CHROMOSOME 1 and the gene for PROTO-ONCOGENE PROTEINS C-MET.

Oncogene Protein v-akt [M0150731]
A viral oncoprotein originally isolated from a murine T CELL LYMPHOMA infected with the acutely transforming retrovirus AKT8. v-akt protein is the viral homologue of PROTO-ONCOGENE PROTEINS C-AKT.

Oncogene Protein v-cbl [M0163413]
An oncoprotein from the Cas NS-1 murine retrovirus that induces pre- B-CELL LYMPHOMA and MYELOID LEUKEMIAS. v-cbl protein is a tyrosine-phosphorylated, truncated form of its cellular homologue, PROTO-ONCOGENE PROTEIN C-CBL.

Oncogene Protein v-crk [M0171182]
A signal transducing adaptor protein that is encoded by the crk ONCOGENE from TYPE C AVIAN RETROVIRUSES. It contains SRC HOMOLOGY DOMAINS and is closely related to its cellular homolog, PROTO-ONCOGENE PROTEIN C-CRK.

Oncogene Protein v-fes [M0024044]

Oncogene Protein v-maf [M0478895]
An oncogene protein that was originally isolated from a spontaneous musculo-aponeurotic FIBROSARCOMA in CHICKEN and shown to be the transforming gene of the avian retrovirus AS42. It is a basic leucine zipper TRANSCRIPTION FACTOR and the founding member of the MAF TRANSCRIPTION FACTORS.

Oncogene Proteins [M0023873]
Proteins coded by oncogenes. They include proteins resulting from the fusion of an oncogene and another gene (ONCOGENE PROTEINS, FUSION).

Oncogene Proteins v-abl [M0025052]
Transforming proteins encoded by the abl oncogenes. Oncogenic transformation of c-abl to v-abl occurs by insertional activation that results in deletions of specific N-terminal amino acids.

Oncogene Proteins v-erbA [M0028105]
Transforming proteins encoded by erbA oncogenes from the avian erythroblastosis virus. They are truncated versions of c-erbA, the thyroid hormone receptor (RECEPTORS, THYROID HORMONE) that have retained both the DNA-binding and hormone-binding domains. Mutations in the hormone-binding domains abolish the transcriptional activation function. v-erbA acts as a dominant repressor of c-erbA, inducing transformation by disinhibiting proliferation.

Oncogene Proteins v-erbB [M0028074]
Transforming proteins encoded by erbB oncogenes from the avian erythroblastosis virus. The protein is a truncated form of the EGF receptor (RECEPTOR, EPIDERMAL GROWTH FACTOR) whose kinase domain is constitutively activated by deletion of the ligand-binding domain.

Oncogene Proteins v-fos [M0025545]
Transforming proteins coded by fos oncogenes. These proteins have been found in the Finkel-Biskis-Jinkins (FBJ-MSV) and Finkel-Biskis-Reilly (FBR-MSV) murine sarcoma viruses which induce osteogenic sarcomas in mice. The FBJ-MSV v-fos gene encodes a p55-kDa protein and the FBR-MSV v-fos gene encodes a p75-kDa fusion protein.

Oncogene Proteins v-mil [M0380023]

Oncogene Proteins v-mos [M0026145]
Transforming proteins coded by mos oncogenes. The v-mos proteins were originally isolated from the Moloney murine sarcoma virus (Mo-MSV).

Oncogene Proteins v-myb [M0328549]
Transforming proteins coded by myb oncogenes. Transformation of cells by v-myb in conjunction with v-ets is seen in the avian E26 leukemia virus.

Oncogene Proteins v-raf [M0143881]
A family of transforming proteins isolated from retroviruses such as MOUSE SARCOMA VIRUSES. They are viral-derived members of the raf-kinase family of serine-theonine kinases.

Oncogene Proteins v-rel [M0328551]
Transforming proteins coded by rel oncogenes. The v-rel protein competes with rel-related proteins and probably transforms cells by acting as a dominant negative version of c-rel. This results in the induction of a broad range of leukemias and lymphomas.

Oncogene Proteins v-sis [M0328552]
Transforming proteins coded by sis oncogenes. Transformation of cells by v-sis is related to its interaction with the PDGF receptor and also its ability to alter other transcription factors.

Oncogene Proteins, Fusion [M0023875]
The GENETIC TRANSLATION products of the fusion between an ONCOGENE and another gene. The latter may be of viral or cellular origin.

Oncogene Proteins, Viral [M0015296]
Products of viral oncogenes, most commonly retroviral oncogenes. They usually have transforming and often protein kinase activities.

Oncostatin M [M0145692]
A cytokine with both pro- and anti-inflammatory actions that depend upon the cellular microenvironment. Oncostatin M is a 28 kDa monomeric glycoprotein that is similar in structure to LEUKEMIA INHIBITORY FACTOR. Its name derives from the the observation that it inhibited the growth of tumor cells and augmented the growth of normal fibroblasts.

Oncostatin M Receptor beta Subunit [M0444722]
An ONCOSTATIN M-specific receptor subunit that combines with CYTOKINE RECEPTOR GP130 to form the ONCOSTATIN M TYPE II RECEPTOR.

One-Carbon Group Transferases [M0029511]
A subclass of transferases that transfer chemical groups containing a single carbon. These include the METHYLTRANSFERASES, the HYDROXYMETHYL AND FORMYL TRANSFERASES, the CARBOXYL AND CARBAMOYL TRANSFERASES, and the AMIDINOTRANSFERASES. EC 2.1.

Onecut Transcription Factors [M0481012]
A family of transcription factors that contain a single cut domain and a divergent homeodomain. They regulate gene networks by controlling the expression of other transcription factors and they play an important role in CELL DIFFERENTIATION and METABOLISM.

Opioid Peptides [M0028201]
The endogenous peptides with opiate-like activity. The three major classes currently recognized are the ENKEPHALINS, the DYNORPHINS, and the ENDORPHINS. Each of these families derives from different precursors, proenkephalin, prodynorphin, and PRO-OPIOMELANOCORTIN, respectively. There are also at least three classes of OPIOID RECEPTORS, but the peptide families do not map to the receptors in a simple way.

Opsin [M0026259]
A visual pigment protein found in the retinal rods. It combines with retinaldehyde to form RHODOPSIN.

Opsonin Proteins [M0484835]
Proteins that bind to particles and cells to increase susceptibility to PHAGOCYTOSIS, especially ANTIBODIES bound to EPITOPES that attach to FC RECEPTORS. COMPLEMENT C3B may also participate.

Optimax [M0485379]

Org 32489 [M0211977]

ORG-31338 [M0013387]

Organic Anion Transport Polypeptide C [M0369303]
An organic anion transporter found in human liver. It is capable of transporting a variety organic anions and mediates sodium-independent uptake of bile in the liver.

Organic Anion Transport Polypeptides [M0384534]
A sub-family of sequence-related ORGANIC ANION TRANSPORTERS.

Organic Anion Transport Protein 1 [M0363716]
A polyspecific transporter for organic cations found primarily in the kidney. It mediates the coupled exchange of alpha-ketoglutarate with organic ions such as P-AMINOHIPPURIC ACID.

Organic Anion Transport Proteins [M0384499]
A sub-family of sequence-related ORGANIC ANION TRANSPORTERS.

Organic Anion Transporters [M0076804]
Proteins involved in the transport of organic anions. They play an important role in the elimination of a variety of endogenous substances, xenobiotics and their metabolites from the body.

Organic Anion Transporters, ATP-Dependent [M0384551]
A subclass of ORGANIC ANION TRANSPORTERS whose transport of organic anions is linked directly to the hydrolysis of ATP. The subclass includes those ATP-BINDING CASSETTE TRANSPORTERS that transport organic ions.

Organic Anion Transporters, Sodium-Dependent [M0384546]
A subclass of ORGANIC ANION TRANSPORTERS whose transport of organic anions is driven either directly or indirectly by a gradient of sodium ions.

Organic Anion Transporters, Sodium-Independent [M0384540]
A subclass of ORGANIC ANION TRANSPORTERS that do not rely directly or indirectly upon sodium ion gradients for the transport of organic ions.

Organic Cation Transport Proteins [M0380850]
A family of proteins involved in the transport of organic cations. They play an important role in the elimination of a variety of endogenous substances, xenobiotics, and their metabolites from the body.

Organic Cation Transporter 1 [M0240044]
An organic cation transporter found in kidney. It is localized to the basal lateral membrane and is likely to be involved in the renal secretion of organic cations.

Origin Recognition Complex [M0223226]
The origin recognition complex is a multi-subunit DNA-binding protein that initiates DNA REPLICATION in eukaryotes.

Origin Recognition Complex Proteins [M0483546]

Origin Recognition Complex, Subunit 1 [M0223215]

Origin Recognition Complex, Subunit 2 [M0223216]

Origin Recognition Complex, Subunit 3 [M0223217]

Origin Recognition Complex, Subunit 4 [M0223218]

Origin Recognition Complex, Subunit 5 [M0223219]

Origin Recognition Complex, Subunit 6 [M0223222]

Ornipressin [M0015429]
A synthetic analog of vasopressin with ORNITHINE substitution at residue 8 of the cyclic nonapeptide. It is used as a local vasoconstrictor and hemostatic.

Ornithine [M0015430]
An amino acid produced in the urea cycle by the splitting off of urea from arginine.

Ornithine Carbamoyltransferase [M0015432]
A urea cycle enzyme that catalyzes the formation of orthophosphate and L-citrulline (CITRULLINE) from CARBAMOYL PHOSPHATE and L-ornithine (ORNITHINE). Deficiency of this enzyme may be transmitted as an X-linked trait. EC 2.1.3.3.

Ornithine Decarboxylase [M0015433]
A pyridoxal-phosphate protein, believed to be the rate-limiting compound in the biosynthesis of polyamines. It catalyzes the decarboxylation of ornithine to form putrescine, which is then linked to a propylamine moiety of decarboxylated S-adenosylmethionine to form spermidine. EC 4.1.1.17.

Ornithine Dihydrochloride, (L)-Isomer [M0330005]

Ornithine Hydrochloride, (D)-Isomer [M0329871]

Ornithine Hydrochloride, (DL)-Isomer [M0330000]

Ornithine Hydrochloride, (L)-Isomer [M0329999]

Ornithine Monoacetate, (L)-Isomer [M0330003]

Ornithine Monohydrobromide, (L)-Isomer [M0330002]

Ornithine Monohydrochloride, (D)-Isomer [M0329998]

Ornithine Monohydrochloride, (DL)-Isomer [M0329997]

Ornithine Phosphate (1:1), (L)-Isomer [M0330007]

Ornithine Sulfate (1:1), (L)-Isomer [M0329939]

Ornithine, (D)-Isomer [M0330001]

Ornithine, (DL)-Isomer [M0330004]

Ornithine, (L)-Isomer [M0330006]

Ornithine-Oxo-Acid Transaminase [M0015431]
A pyridoxal phosphate enzyme that catalyzes the formation of glutamate gamma-semialdehyde and an L-amino acid from L-ornithine and a 2-keto-acid. EC 2.6.1.13.

Orosomucoid [M0015443]

Orotate Phosphoribosyltransferase [M0015445]
The enzyme catalyzing the formation of orotidine-5'-phosphoric acid (orotidylic acid) from orotic acid and 5-phosphoribosyl-1-pyrophosphate in the course of pyrimidine nucleotide biosynthesis. EC 2.4.2.10.

Orotidine-5'-Phosphate Decarboxylase [M0015450]
Orotidine-5'-phosphate carboxy-lyase. Catalyzes the decarboxylation of orotidylic acid to yield uridylic acid in the final step of the pyrimidine nucleotide biosynthesis pathway. EC 4.1.1.23.

Oroxine [M0463515]

Orthoclone OKT3 [M0373290]

Oryzacystatin [M0024323]

Osteocalcin [M0024030]
Vitamin K-dependent calcium-binding protein synthesized by OSTEOBLASTS and found primarily in BONES. Serum osteocalcin measurements provide a noninvasive specific marker of bone metabolism. The protein contains three residues of the amino acid gamma-carboxyglutamic acid (Gla), which, in the presence of CALCIUM, promotes binding to HYDROXYAPATITE and subsequent accumulation in BONE MATRIX.

Osteonectin [M0024031]
Non-collagenous, calcium-binding glycoprotein of developing bone. It links collagen to mineral in the bone matrix. In the synonym SPARC glycoprotein, the acronym stands for Secreted Protein, Acidic and Rich in Cysteine.

Osteopontin [M0144031]
A negatively-charged extracellular matrix protein that plays a role in the regulation of BONE metabolism and a variety of other biological functions. Cell signaling by osteopontin may occur through a cell adhesion sequence that recognizes INTEGRIN ALPHA-V BETA-3.

Osteoprotegerin [M0275318]
A secreted member of the TNF receptor superfamily that negatively regulates osteoclastogenesis. It is a soluble decoy receptor of RANK LIGAND that inhibits both CELL DIFFERENTIATION and function of OSTEOCLASTS by inhibiting the interaction between RANK LIGAND and RECEPTOR ACTIVATOR OF NUCLEAR FACTOR-KAPPA B.

Otx Transcription Factors [M0364810]
A family of VERTEBRATE homeodomain proteins that share homology with orthodenticle protein, Drosophila. They regulate GENETIC TRANSCRIPTION and play an important role in EMBRYONIC DEVELOPMENT of the BRAIN.

Otx1 Transcription Factor [M0481976]

Otx2 Transcription Factor [M0219147]

Outer Membrane Lipoproteins, Bacterial [M0002128]

Ovalbumin [M0015587]
An albumin obtained from the white of eggs. It is a member of the serpin superfamily.

Ovomucin [M0015601]
A heterogeneous mixture of glycoproteins responsible for the gel structure of egg white. It has trypsin-inhibiting activity.

Ovoperoxidase [M0016375]

OX40 Ligand [M0492257]
A membrane-bound tumor necrosis family member that is expressed on activated antigen-presenting cells such as B-LYMPHOCYTES and MACROPHAGES. It signals T-LYMPHOCYTES by binding the OX40 RECEPTOR.

Oxamic Acid [M0015633]
Amino-substituted glyoxylic acid derivative.

Oxidase [M0015650]

Oxidative Phosphorylation Coupling Factors [M0015647]

Oxidoreductases [M0015649]
The class of all enzymes catalyzing oxidoreduction reactions. The substrate that is oxidized is regarded as a hydrogen donor. The systematic name is based on donor:acceptor oxidoreductase. The recommended name will be dehydrogenase, wherever this is possible; as an alternative, reductase can be used. Oxidase is only used in cases where O2 is the acceptor. (Enzyme Nomenclature, 1992, p9)

Oxidoreductases Acting on Aldehyde or Oxo Group Donors [M0478221]
A broad category of oxidoreductases that either reduce double bonds or oxidize single bonds between OXYGEN and CARBON in organic compounds.

Oxidoreductases Acting on CH-CH Group Donors [M0446687]
A subclass of enzymes which includes all dehydrogenases acting on carbon-carbon bonds. This enzyme group includes all the enzymes that introduce double bonds into substrates by direct dehydrogenation of carbon-carbon single bonds.

Oxidoreductases Acting on CH-NH Group Donors [M0000912]
Enzymes catalyzing the dehydrogenation of secondary amines, introducing a C=N double bond as the primary reaction. In some cases this is later hydrolyzed.

Oxidoreductases Acting on CH-NH2 Group Donors [M0478476]
Enzymes catalyzing the dehydrogenation of or oxidation of compounds containing primary amines.

Oxidoreductases Acting on Sulfur Group Donors [M0478367]
Oxidoreductases with specificity for oxidation or reduction of SULFUR COMPOUNDS.

Oxidoreductases, N-Demethylating [M0015651]

Oxidoreductases, O-Demethylating [M0015652]
Drug metabolizing enzymes which oxidize methyl ethers. Usually found in liver microsomes.

Oxo-Acid-Lyases [M0011985]
Enzymes that catalyze the cleavage of a carbon-carbon bond of a 3-hydroxy acid. (Dorland, 28th ed) EC 4.1.3.

Oxycobalthemoglobin [M0015679]

Oxygenases [M0015676]
Oxidases that specifically introduce DIOXYGEN-derived oxygen atoms into a variety of organic molecules.

Oxyhemoglobins [M0015680]
A compound formed by the combination of hemoglobin and oxygen. It is a complex in which the oxygen is bound directly to the iron without causing a change from the ferrous to the ferric state.

Oxyntomodulin [M0483763]
A 37-amino acid peptide derived from the C-terminal of GLICENTIN. It is mainly produced by the INTESTINAL L CELLS. Oxyntomodulin can reduce digestive secretions, delay gastric emptying, and reduced food intake.

Oxytocin [M0015703]
A nonapeptide hormone released from the neurohypophysis (PITUITARY GLAND, POSTERIOR). It differs from VASOPRESSIN by two amino acids at residues 3 and 8. Oxytocin acts on smooth muscle cells, such as causing UTERINE CONTRACTIONS and MILK EJECTION.

P-113 [M0372432]

P-113 Acetate [M0372431]

P-Cadherins [M0024237]

p-Fluorophenylalanine [M0015727]
3-(p-Fluorophenyl)-alanine.

P-Glycoprotein [M0029890]
A 170-kDa transmembrane glycoprotein from the superfamily of ATP-BINDING CASSETTE TRANSPORTERS. It serves as an ATP-dependent efflux pump for a variety of chemicals, including many ANTINEOPLASTIC AGENTS. Overexpression of this glycoprotein is associated with multidrug resistance (see DRUG RESISTANCE, MULTIPLE).

P-Glycoproteins [M0027659]
A subfamily of transmembrane proteins from the superfamily of ATP-BINDING CASSETTE TRANSPORTERS that are closely related in sequence to P-GLYCOPROTEIN. When overexpressed, they function as ATP-dependent efflux pumps able to extrude lipophilic drugs, especially ANTINEOPLASTIC AGENTS, from cells causing multidrug resistance (DRUG RESISTANCE, MULTIPLE). Although P-Glycoproteins share functional similarities to MULTIDRUG RESISTANCE-ASSOCIATED PROTEINS they are two distinct subclasses of ATP-BINDING CASSETTE TRANSPORTERS, and have little sequence homology.

p-Nitrophenyl UDP-Glucuronosyltransferase [M0022222]

P-Selectin [M0028385]
Cell adhesion molecule and CD antigen that mediates the adhesion of neutrophils and monocytes to activated platelets and endothelial cells.

p100-GAP Protein [M0156259]

p102 Protein (Golgi) [M0219149]

p105-Rb Protein [M0024672]

p120 GTPase Activating Protein [M0328218]
A 120-kDa RAS GTPase-activating protein that binds to tyrosine phosphoproteins through its SH2 domains. The 100-kDa RNA-splicing variant (p100 GAP protein) is expressed in placenta.

p120(cbl) [M0477401]

p140 gag-fes [M0024045]

p140 gag-fps [M0024046]

p200 gag-pol-myc [M0024047]

P30 Core Proteins [M0022704]

p300-CBP Transcription Factors [M0232680]
A family of histone acetyltransferases that is structurally-related to CREB-BINDING PROTEIN and to E1A-ASSOCIATED P300 PROTEIN. They function as transcriptional coactivators by bridging between DNA-binding TRANSCRIPTION FACTORS and the basal transcription machinery. They also modify transcription factors and CHROMATIN through ACETYLATION.

p34cdc2 Protein [M0442232]

p34cdc28 Kinase, S cerevisiae [M0194886]

p38 Mitogen-Activated Protein Kinases [M0234432]
A mitogen-activated protein kinase subfamily that regulates a variety of cellular processes including CELL GROWTH PROCESSES; CELL DIFFERENTIATION; APOPTOSIS; and cellular responses to INFLAMMATION. The P38 MAP kinases are regulated by CYTOKINE RECEPTORS and can be activated in response to bacterial pathogens.

p40 Mitogen-Activated Protein Kinase [M0230239]

p41 Mitogen-Activated Protein Kinase [M0333265]

p55(v-fos) [M0025547]

p67 Serum Response Factor [M0160470]

p75 gag-fos [M0025549]

p75(gag-fos-fox) [M0025548]

p85(gag-mos) [M0026144]

Padutin [M0332548]

Paired Box Transcription Factors [M0481735]
A family of transcription factors that control EMBRYONIC DEVELOPMENT within a variety of cell lineages. They are characterized by a highly conserved paired DNA-binding domain that was first identified in DROSOPHILA segmentation genes.

Palmitoyl-CoA Hydrolase [M0015779]
Enzyme catalyzing reversibly the hydrolysis of palmitoyl-CoA or other long-chain acyl coenzyme A compounds to yield CoA and palmitate or other acyl esters. The enzyme is involved in the esterification of fatty acids to form triglycerides. EC 3.1.2.2.

Palmitoylcarnitine [M0015783]
A long-chain fatty acid ester of carnitine which facilitates the transfer of long-chain fatty acids from cytoplasm into mitochondria during the oxidation of fatty acids.

PAMP(1-20)NH2 [M0459452]

Panangin [M0017382]

Pancrease [M0045746]

Pancreatic Elastase [M0015812]
A protease of broad specificity, obtained from dried pancreas. Molecular weight is approximately 25,000. The enzyme breaks down elastin, the specific protein of elastic fibers, and digests other proteins such as fibrin, hemoglobin, and albumin. EC 3.4.21.36.

Pancreatic Hormones [M0015800]
Peptide hormones secreted into the blood by cells in the ISLETS OF LANGERHANS of the pancreas. The alpha cells secrete glucagon; the beta cells secrete insulin; the delta cells secrete somatostatin; and the PP cells secrete pancreatic polypeptide.

Pancreatic Polypeptide [M0015804]
A 36-amino acid pancreatic hormone that is secreted mainly by endocrine cells found at the periphery of the ISLETS OF LANGERHANS and adjacent to cells containing SOMATOSTATIN and GLUCAGON. Pancreatic polypeptide (PP), when administered peripherally, can suppress gastric secretion, gastric emptying, pancreatic enzyme secretion, and appetite. A lack of pancreatic polypeptide (PP) has been associated with OBESITY in rats and mice.

Pancreatic Prohormone [M0496467]
A secreted polypeptide of about 100 amino acids, depending on the species, from the PANCREASE. It is the precursor of pancreatic polypeptide (PP) and a pancreatic C-terminal peptide or pancreatic icosapeptide.

Pancreatin [M0015807]
A mammalian pancreatic extract composed of enzymes with protease, amylase and lipase activities. It is used as a digestant in pancreatic malfunction.

Pancrecarb [M0474982]

Pancrelipase [M0045748]
A preparation of hog pancreatic enzymes standardized for lipase content.

Pancron [M0474983]

Pangen [M0369418]

Panokase [M0474984]

Panteric [M0333687]

Pantothenic Acid [M0015824]
A butyryl-beta-alanine that can also be viewed as pantoic acid complexed with BETA ALANINE. It is incorporated into COENZYME A and protects cells against peroxidative damage by increasing the level of GLUTATHIONE.

Panzytrat [M0333686]

Papain [M0015826]
A proteolytic enzyme obtained from Carica papaya. It is also the name used for a purified mixture of papain and CHYMOPAPAIN that is used as a topical enzymatic debriding agent. EC 3.4.22.2.

Papillomavirus E7 Proteins [M0477407]
ONCOGENE PROTEINS from papillomavirus that deregulate the CELL CYCLE of infected cells and lead to NEOPLASTIC CELL TRANSFORMATION. Papillomavirus E7 proteins have been shown to interact with various regulators of the cell cycle including RETINOBLASTOMA PROTEIN and certain cyclin-dependent kinase inhibitors.

Paracrine Peptide Factors [M0409593]

Paracrine Protein Factors [M0409592]

Paramyosin [M0022044]

Paramyxovirus Fusion Protein [M0022727]

Paraoxonase-1 [M0444855]

Paraoxonase-2 [M0444856]

Paraproteins [M0015906]
Abnormal immunoglobulins synthesized by atypical cells of the RETICULOENDOTHELIAL SYSTEM. Paraproteins containing only light chains lead to Bence Jones paraproteinemia, while the presence of only atypical heavy chains leads to heavy chain disease. Most of the paraproteins show themselves as an M-component (monoclonal gammopathy) in electrophoresis. Diclonal and polyclonal paraproteins are much less frequently encountered.

Parathar [M0028837]

Parathyroid Calcium-Sensing Receptor [M0225061]

Parathyroid Hormone [M0015931]
A polypeptide hormone (84 amino acid residues) secreted by the PARATHYROID GLANDS which performs the essential role of maintaining intracellular CALCIUM levels in the body. Parathyroid hormone increases intracellular calcium by promoting the release of CALCIUM from BONE, increases the intestinal absorption of calcium, increases the renal tubular reabsorption of calcium, and increases the renal excretion of phosphates.

Parathyroid Hormone-Related Protein [M0150746]
A ubiquitously expressed, secreted protein with bone resorption and renal calcium reabsorption activities that are similar to PARATHYROID HORMONE. It does not circulate in appreciable amounts in normal subjects, but rather exerts its biological actions locally. Overexpression of parathyroid hormone-related protein by tumor cells results in humoral calcemia of malignancy.

Parathyroid Secretory Protein [M0492859]

parC Protein [M0379539]
One of the two subunits in DNA topoisomerase IV.

parE Protein [M0210672]
One of the two subunits in DNA topoisomerase IV.

Paronal [M0434512]

Parvalbumin B [M0015993]

Parvalbumins [M0015994]
Low molecular weight, calcium binding muscle proteins. Their physiological function is possibly related to the contractile process.

Paul-Bunnell Antibodies [M0465765]

PAX2 Transcription Factor [M0197410]
A paired box transcription factor that is essential for ORGANOGENESIS of the CENTRAL NERVOUS SYSTEM and KIDNEY.

Pax5A Transcription Factor [M0394835]
Pax5A transcription factor is the major isoform of B-cell-specific activator protein.

PAX7 Transcription Factor [M0221795]
A paired box transcription factor that is involved in EMBRYONIC DEVELOPMENT of the CENTRAL NERVOUS SYSTEM and SKELETAL MUSCLE.

PAX9 Transcription Factor [M0220627]
A paired box transcription factor that is involved in ODONTOGENESIS.

Paxillin [M0193207]
Paxillin is a signal transducing adaptor protein for CELL MIGRATION that localizes primarily to FOCAL ADHESIONS. It undergoes PHOSPHORYLATION in response to integrin-mediated CELL ADHESION, and interacts with a variety of proteins including VINCULIN; FOCAL ADHESION KINASE; PROTO-ONCOGENE PROTEIN PP60(C-SRC); and PROTO-ONCOGENE PROTEIN C-CRK.

PC5A Proprotein Convertase [M0447573]

PC5B Preprotein Convertase [M0447574]

PC6A Proprotein Convertase [M0449071]

Peanut Agglutinin [M0029528]
Lectin purified from peanuts (ARACHIS HYPOGAEA). It binds to poorly differentiated cells and terminally differentiated cells and is used in cell separation techniques.

Pedameth [M0013576]

Penicillamine [M0016122]
3-Mercapto-D-valine. The most characteristic degradation product of the penicillin antibiotics. It is used as an antirheumatic and as a chelating agent in Wilson's disease.

Penicillin Amidase [M0016130]
An enzyme catalyzing the hydrolysis of penicillin to penicin and a carboxylic acid anion. EC 3.5.1.11.

Penicillin G Acylase [M0016131]

Penicillin V Acylase [M0016132]

Penicillin-Binding Protein 1 [M0068519]

Penicillin-Binding Protein 1A [M0107496]

Penicillin-Binding Protein 1b [M0107498]

Penicillin-Binding Protein 2 [M0107499]

Penicillin-Binding Protein 2a [M0068523]

Penicillin-Binding Protein 2b [M0454417]

Penicillin-Binding Protein 3 [M0107500]

Penicillin-Binding Protein 4 [M0068524]

Penicillin-Binding Protein 5 [M0068521]

Penicillin-Binding Protein 6 [M0068518]

Penicillin-Binding Protein 7 [M0068522]

Penicillin-Binding Proteins [M0068526]
Bacterial proteins that share the property of binding irreversibly to PENICILLINS and other ANTIBACTERIAL AGENTS derived from LACTAMS. The penicillin-binding proteins are primarily enzymes involved in CELL WALL biosynthesis including MURAMOYLPENTAPEPTIDE CARBOXYPEPTIDASE; PEPTIDE SYNTHASES; TRANSPEPTIDASES; and HEXOSYLTRANSFERASES.

Penicillinase [M0016151]
A beta-lactamase preferentially cleaving penicillins. (Dorland, 28th ed) EC 3.5.2.-.

Penicillium Citrium Nuclease P1 [M0024105]

Pentagastrin [M0016168]
A synthetic pentapeptide that has effects like gastrin when given parenterally. It stimulates the secretion of gastric acid, pepsin, and intrinsic factor, and has been used as a diagnostic aid.

Pentasa [M0029388]

Pentosyltransferases [M0016197]
Enzymes of the transferase class that catalyze the transfer of a pentose group from one compound to another. (Dorland, 28th ed) EC 2.4.2.

Peplomycin [M0026717]
An antineoplastic agent derived from BLEOMYCIN.

Peplomycin Sulfate [M0329228]

Peplomycin Sulfate (1:1) [M0329227]

Pepsin 1 [M0016205]

Pepsin 3 [M0016206]

Pepsin A [M0016204]
Formed from pig pepsinogen by cleavage of one peptide bond. The enzyme is a single polypeptide chain and is inhibited by methyl 2-diaazoacetamidohexanoate. It cleaves peptides preferentially at the carbonyl linkages of phenylalanine or leucine and acts as the principal digestive enzyme of gastric juice.

Pepsinogen 3, Group I [M0029856]

Pepsinogen 5, Group I [M0029857]

Pepsinogen A [M0029855]
This is one of 2 related pepsinogen systems in humans and is also known as pepsinogen. (The other is PEPSINOGEN C.) This includes isozymogens Pg1-Pg5 (pepsinogens 1-5, group I or products of PGA1-PGA5 genes). This is the main pepsinogen found in urine.

Pepsinogen B [M0016208]

Pepsinogen C [M0029854]
This is one of the 2 related pepsinogen systems in humans. It is found in prostate and seminal fluid whereas PEPSINOGEN A is not.

Pepsinogens [M0016207]
Proenzymes secreted by chief cells, mucous neck cells, and pyloric gland cells, which are converted into pepsin in the presence of gastric acid or pepsin itself. (Dorland, 28th ed) In humans there are 2 related pepsinogen systems: PEPSINOGEN A (formerly pepsinogen I or pepsinogen) and PEPSINOGEN C (formerly pepsinogen II or progastricsin). Pepsinogen B is the name of a pepsinogen from pigs.

Pepstatins [M0016209]
N-acylated oligopeptides isolated from culture filtrates of Actinomycetes, which act specifically to inhibit acid proteases such as pepsin and renin.

Peptavlon [M0373136]

Peptichemio [M0016214]
A mixture of six synthetic oligopeptides, each containing MELPHALAN. It is used as a broad-spectrum antineoplastic due to its alkylating and antimetabolic actions but, is toxic to bone marrow, gastrointestinal system and vasculature.

Peptide Elongation Factor 1 [M0328220]
Peptide elongation factor 1 is a multisubunit protein that is responsible for the GTP-dependent binding of aminoacyl-tRNAs to eukaryotic ribosomes. The alpha subunit (EF-1alpha) binds aminoacyl-tRNA and transfers it to the ribosome in a process linked to GTP hydrolysis. The beta and delta subunits (EF-1beta, EF-1delta) are involved in exchanging GDP for GTP. The gamma subunit (EF-1gamma) is a structural component.

Peptide Elongation Factor 2 [M0328223]
Peptide Elongation Factor 2 catalyzes the translocation of peptidyl-tRNA from the A site to the P site of eukaryotic ribosomes by a process linked to the hydrolysis of GTP to GDP.

Peptide Elongation Factor G [M0328225]
Peptide Elongation Factor G catalyzes the translocation of peptidyl-tRNA from the A to the P site of bacterial ribosomes by a process linked to hydrolysis of GTP to GDP.

Peptide Elongation Factor Tu [M0016221]
A protein found in bacteria and eukaryotic mitochondria which delivers aminoacyl-tRNA's to the A site of the ribosome. The aminoacyl-tRNA is first bound to a complex of elongation factor Tu containing a molecule of bound GTP. The resulting complex is then bound to the 70S initiation complex. Simultaneously the GTP is hydrolyzed and a Tu-GDP complex is released from the 70S ribosome. The Tu-GTP complex is regenerated from the Tu-GDP complex by the Ts elongation factor and GTP. EC 3.6.1.-.

Peptide Elongation Factors [M0016222]
Protein factors uniquely required during the elongation phase of protein synthesis.

Peptide Fragments [M0016224]
Partial proteins formed by partial hydrolysis of complete proteins.

Peptide Hormone Receptors [M0027183]

Peptide Hormones [M0409611]
Hormones synthesized from amino acids. They are distinguished from INTERCELLULAR SIGNALING PEPTIDES AND PROTEINS in that their actions are systemic.

Peptide Hydrolases [M0016225]
Hydrolases that specifically cleave the peptide bonds found in PROTEINS and PEPTIDES. Examples of sub-subclasses for this group include EXOPEPTIDASES and ENDOPEPTIDASES.

Peptide Initiation Factors [M0016226]
Protein factors uniquely required during the initiation phase of protein synthesis in GENETIC TRANSLATION.

Peptide Library [M0028555]
A collection of cloned peptides, or chemically synthesized peptides, frequently consisting of all possible combinations of amino acids making up an n-amino acid peptide.

Peptide PHI [M0016232]
A 27-amino acid peptide with histidine at the N-terminal and isoleucine amide at the C-terminal. The exact amino acid composition of the peptide is species dependent. The peptide is secreted in the intestine, but is found in the nervous system, many organs, and in the majority of peripheral tissues. It has a wide range of biological actions, affecting the cardiovascular, gastrointestinal, respiratory, and central nervous systems.

Peptide Synthases [M0016235]
Ligases that catalyze the joining of adjacent AMINO ACIDS by the formation of carbon-nitrogen bonds between their carboxylic acid groups and amine groups.

Peptide T [M0024099]
N-(N-(N(2)-(N-(N-(N-(N-D-Alanyl L-seryl)-L-threonyl)-L-threonyl) L-threonyl)-L-asparaginyl)-L-tyrosyl) L-threonine. Octapeptide sharing sequence homology with HIV envelope protein gp120. It is potentially useful as antiviral agent in AIDS therapy. The core pentapeptide sequence, TTNYT, consisting of amino acids 4-8 in peptide T, is the HIV envelope sequence required for attachment to the CD4 receptor.

Peptide Termination Factors [M0016236]
Proteins that are involved in the peptide chain termination reaction (PEPTIDE CHAIN TERMINATION, TRANSLATIONAL) on RIBOSOMES. They include codon-specific class-I release factors, which recognize stop signals (TERMINATOR CODON) in the MESSENGER RNA; and codon-nonspecific class-II release factors.

Peptide YY [M0029538]
A 36-amino acid peptide produced by the L cells of the distal small intestine and colon. Peptide YY inhibits gastric and pancreatic secretion.

Peptide-N4-(N-acetyl-beta-glucosaminyl) Asparagine Amidase [M0075003]
An amidohydrolase that removes intact asparagine-linked oligosaccharide chains from glycoproteins. It requires the presence of more than two amino-acid residues in the substrate for activity. This enzyme was previously listed as EC 3.2.2.18.

Peptides [M0016238]
Members of the class of compounds composed of AMINO ACIDS joined together by peptide bonds between adjacent amino acids into linear, branched or cyclical structures. OLIGOPEPTIDES are composed of approximately 2-12 amino acids. Polypeptides are composed of approximately 13 or more amino acids. PROTEINS are linear polypeptides that are normally synthesized on RIBOSOMES.

Peptides, Cyclic [M0016239]

Peptidoglycan Glycosyltransferase [M0091146]
A hexosyltransferase involved in the transfer of disaccharide molecules to the peptidoglycan structure of the CELL WALL SKELETON. It plays an important role in the genesis of the bacterial CELL WALL.

Peptidoglycan Synthetase [M0107502]
A complex of enzymes that synthesize the peptidoglycan cell wall structure.

Peptidyl Transferases [M0016242]
Acyltransferases that use AMINO ACYL TRNA as the amino acid donor in formation of a peptide bond. There are ribosomal and non-ribosomal peptidyltransferases.

Peptidyl-Dipeptidase A [M0012049]
A peptidyl-dipeptidase that catalyzes the release of a C-terminal dipeptide, -Xaa-*-Xbb-Xcc, when neither Xaa nor Xbb is Pro. It is a Cl(-)-dependent, zinc glycoprotein that is generally membrane-bound and active at neutral pH. It may also have endopeptidase activity on some substrates. (From Enzyme Nomenclature, 1992) EC 3.4.15.1.

Peptidylprolyl Isomerase [M0029248]
An enzyme that catalyzes the isomerization of proline residues within proteins. EC 5.2.1.8.

Peptoids [M0405653]
Polymers of N-SUBSTITUTED GLYCINES containing chiral centers at the a-position of their side chains. These oligomers lack HYDROGEN BONDING donors, preventing formation of the usual intrachain hydrogen bonds but can form helices driven by the steric influence of chiral side chains.

Peptones [M0016245]
Derived proteins or mixtures of cleavage products produced by the partial hydrolysis of a native protein either by an acid or by an enzyme. Peptones are readily soluble in water, and are not precipitable by heat, by alkalis, or by saturation with ammonium sulfate. (Dorland, 28th ed)

Pergonal [M0013390]

Pergonal-500 [M0013386]

Periplasmic Binding Proteins [M0003560]
Periplasmic proteins that scavenge or sense diverse nutrients. In the bacterial environment they usually couple to transporters or chemotaxis receptors on the inner bacterial membrane.

Periplasmic Proteins [M0404294]
Proteins found in the PERIPLASM of organisms with cell walls.

Permeases [M0016369]
Any of a group of enzymes which mediate the phenomenon of active transport (McGraw-Hill Dictionary of Scientific and Technical Terms, 5th ed). Although proteins in this class are sometimes referred to an enzymes they have not been accepted as an enzyme class by the Enzyme Commission.

Peroxidase [M0014331]
A hemeprotein from leukocytes. Deficiency of this enzyme leads to a hereditary disorder coupled with disseminated moniliasis. It catalyzes the conversion of a donor and peroxide to an oxidized donor and water. EC 1.11.1.7.

Peroxidases [M0016376]

Peroxisome Proliferator-Activated Receptors [M0199123]
TRANSCRIPTION FACTORS that are activated by ligands and heterodimerize with RETINOID X RECEPTORS and bind to peroxisome proliferator response elements in the promoter regions of target genes.

Pertussis Toxin [M0412510]
One of the virulence factors produced by BORDETELLA PERTUSSIS. It is a multimeric protein composed of five subunits S1 - S5. S1 contains mono ADPribose transferase activity.

Phage Display Peptide Library [M0335875]

Phage Receptors [M0018637]

Phalloidine [M0016455]
Very toxic polypeptide isolated mainly from AMANITA phalloides (Agaricaceae) or death cup; causes fatal liver, kidney and CNS damage in mushroom poisoning; used in the study of liver damage.

Pharmalgen [M0116085]

Phenol Sulfotransferase M [M0023425]

Phenoloxidase A [M0022200]

Phenoloxidase B [M0022201]

Phenolsulfotransferase P [M0023426]

Phenylalanine [M0016544]
An essential aromatic amino acid that is a precursor of MELANIN; DOPAMINE; noradrenalin (NOREPINEPHRINE), and THYROXINE.

Phenylalanine Ammonia-Lyase [M0016545]
An enzyme that catalyzes the deamination of L-phenylalanine to form trans-cinnamate and ammonia. It may also act on L-tyrosine. Since the enzyme deprives neoplastic tissue of phenylalanine, it has been used experimentally in the treatment of acute lymphoblastic leukemia. The enzyme is obtained from many plants. EC 4.3.1.5.

Phenylalanine Hydroxylase [M0016546]
An enzyme of the oxidoreductase class that catalyzes the formation of L-TYROSINE, dihydrobiopterin, and water from L-PHENYLALANINE, tetrahydrobiopterin, and oxygen. Deficiency of this enzyme may cause PHENYLKETONURIAS and PHENYLKETONURIA, MATERNAL. EC 1.14.16.1.

Phenylalanine-tRNA Ligase [M0016547]
An enzyme that activates phenylalanine with its specific transfer RNA. EC 6.1.1.20.

Phenylethanolamine N-Methyltransferase [M0016504]
A methyltransferase that catalyzes the reaction of S-adenosyl-L-methionine and phenylethanolamine to yield S-adenosyl-L-homocysteine and N-methylphenylethanolamine. It can act on various phenylethanolamines and converts norepinephrine into epinephrine. (From Enzyme Nomenclature, 1992) EC 2.1.1.28.

PHEX Phosphate Regulating Neutral Endopeptidase [M0252450]
A membrane-bound metalloendopeptidase that may play a role in the degradation or activation of a variety of PEPTIDE HORMONES and INTERCELLULAR SIGNALING PEPTIDES AND PROTEINS. Genetic mutations that result in loss of function of this protein are a cause of HYPOPHOSPHATEMIC RICKETS, X-LINKED DOMINANT.

Phleomycins [M0016611]
Water-soluble, copper-containing low molecular weight polypeptides obtained from the culture medium of Streptomyces verticillus. They are specific inhibitors of DNA synthesis in bacteria and have been found to act as antitumor agents. They have also been used against rust fungi of plants.

Phosphate Acetyltransferase [M0016635]
An enzyme that catalyzes the synthesis of acetylphosphate from acetyl-CoA and inorganic phosphate. Acetylphosphate serves as a high-energy phosphate compound. EC 2.3.1.8.

Phosphate Carriers [M0386865]

Phosphate Transport Proteins [M0364120]
Membrane proteins that are involved in the active transport of phosphate.

Phosphate-Activated Glutaminase [M0009381]

Phosphate-Binding Proteins [M0075849]
Proteins that bind to and are involved in the metabolism of phosphate ions.

Phosphatidate Phosphatase [M0016638]
A phosphomonoesterase involved in the synthesis of triacylglycerols. It catalyzes the hydrolysis of phosphatidates with the formation of diacylglycerols and orthophosphate. EC 3.1.3.4.

Phosphatidyl-N-Methylethanolamine N-Methyltransferase [M0085809]
An enzyme that catalyzes the METHYLATION of PHOSPHATIDYL-N-METHYLETHANOLAMINE to produce phosphatidyl-N-dimethylethanolamine. This enzyme can also methylate phosphatidyl-N-dimethylethanolamine to produce phosphatidyl-N-trimethylethanolamine (PHOSPHATIDYLCHOLINE).

Phosphatidylcholine Transfer Proteins [M0464770]

Phosphatidylcholine-Sterol O-Acyltransferase [M0012276]
An enzyme secreted from the liver into the plasma of many mammalian species. It catalyzes the esterification of the hydroxyl group of lipoprotein cholesterol by the transfer of a fatty acid from the C-2 position of lecithin. In familial lecithin:cholesterol acyltransferase deficiency disease, the absence of the enzyme results in an excess of unesterified cholesterol in plasma. EC 2.3.1.43.

Phosphatidylethanolamine Binding Protein [M0074920]
A ubiquitously found basic protein that binds to phosphatidylethanolamine and NUCLEOTIDES. It is an endogenous inhibitor of RAF KINASES and may play a role in regulating SIGNAL TRANSDUCTION. Phosphatidylethanolamine-binding protein is the precursor of hippocampal cholinergic neurostimulating peptide, which is cleaved from the N-terminal region of the protein.

Phosphatidylethanolamine N-Methyltransferase [M0078237]
An enzyme that catalyses three sequential METHYLATION reactions for conversion of PHOSPHATIDYLETHANOLAMINE to PHOSPHATIDYLCHOLINE.

Phosphatidylethanolamine N-Methyltransferase-2 [M0078232]

Phosphatidylinositol Diacylglycerol-Lyase [M0077159]
A phosphorus-oxygen lyase found primarily in BACTERIA. The enzyme catalyzes the cleavage of a phosphoester linkage in 1-phosphatidyl-1D-myo-inositol to form 1D-myo-inositol 1,2-cyclic phosphate and diacylglycerol. The enzyme was formerly classified as a phosphoric diester hydrolase (EC 3.1.4.10) and is often referred to as a PHOSPHOLIPASE C. However it is now known that a cyclic phosphate is the final product of this enzyme and that water does not enter into the reaction.

Phosphatidylinositol Transfer Protein alpha [M0424970]

Phosphatidylinositol Transfer Protein beta [M0424969]

Phosphatidylinositol Transfer Proteins [M0464771]

Phosphatidylinositol-Glycan-Specific Phospholipase C [M0439834]

Phosphatidylserine Translocase [M0069069]

Phosphoamino Acids [M0029105]
Amino acids that contain phosphorus as an integral part of the molecule.

Phosphocreatine [M0016657]
An endogenous substance found mainly in skeletal muscle of vertebrates. It has been tried in the treatment of cardiac disorders and has been added to cardioplegic solutions. (Reynolds JEF(Ed): Martindale: The Extra Pharmacopoeia (electronic version). Micromedex, Inc, Englewood, CO, 1996)

Phosphocreatine, Disodium Salt [M0329845]

Phosphodiesterase I [M0078260]
A phosphoric diester hydrolase that removes 5'-nucleotides from the 3'-hydroxy termini of 3'-hydroxy-terminated OLIGONUCLEOTIDES. It has low activity towards POLYNUCLEOTIDES and the presence of 3'-phosphate terminus on the substrate may inhibit hydrolysis.

Phosphoenolpyruvate Carboxykinase (ATP) [M0029325]
An enzyme of the lyase class that catalyzes the conversion of ATP and oxaloacetate to ADP, phosphoenolpyruvate, and carbon dioxide. The enzyme is found in some bacteria, yeast, and Trypanosoma, and is important for the photosynthetic assimilation of carbon dioxide in some plants. EC 4.1.1.49.

Phosphoenolpyruvate Carboxykinase (GTP) [M0016662]
An enzyme of the lyase class that catalyzes the conversion of GTP and oxaloacetate to GDP, phosphoenolpyruvate, and carbon dioxide. This reaction is part of gluconeogenesis in the liver. The enzyme occurs in both the mitochondria and cytosol of mammalian liver. (From Dorland, 27th ed) EC 4.1.1.32.

Phosphoenolpyruvate Carboxylase [M0016663]
An enzyme with high affinity for carbon dioxide. It catalyzes irreversibly the formation of oxaloacetate from phosphoenolpyruvate and carbon dioxide. This fixation of carbon dioxide in several bacteria and some plants is the first step in the biosynthesis of glucose. EC 4.1.1.31.

Phosphoenolpyruvate Hexose Phosphotransferases [M0016666]

Phosphoenolpyruvate Sugar Phosphotransferase System [M0016664]
The bacterial sugar phosphotransferase system (PTS) that catalyzes the transfer of the phosphoryl group from phosphoenolpyruvate to its sugar substrates (the PTS sugars) concomitant with the translocation of these sugars across the bacterial membrane. The phosphorylation of a given sugar requires four proteins, two general proteins, Enzyme I and HPr and a pair of sugar-specific proteins designated as the Enzyme II complex. The PTS has also been implicated in the induction of synthesis of some catabolic enzyme systems required for the utilization of sugars that are not substrates of the PTS as well as the regulation of the activity of adenylate cyclase. EC 2.7.1.-.

Phosphoenolpyruvate-Glycose Phosphotransferase System [M0016665]

Phosphofructokinase-1 [M0016667]
An allosteric enzyme that regulates glycolysis by catalyzing the transfer of a phosphate group from ATP to fructose-6-phosphate to yield fructose-1,6-bisphosphate. D-tagatose- 6-phosphate and sedoheptulose-7-phosphate also are acceptors. UTP, CTP, and ITP also are donors. In human phosphofructokinase-1, three types of subunits have been identified. They are PHOSPHOFRUCTOKINASE-1, MUSCLE TYPE; PHOSPHOFRUCTOKINASE-1, LIVER TYPE; and PHOSPHOFRUCTOKINASE-1, C TYPE; found in platelets, brain, and other tissues.

Phosphofructokinase-1, Liver Type [M0374830]
An allosteric enzyme that regulates glycolysis by catalyzing the transfer of a phosphate group from ATP to fructose-6-phosphate to yield fructose-1,6-bisphosphate. In human liver, the 6-phosphofructose-1-kinase exists as the homotetramer of L subunits.

Phosphofructokinase-1, Muscle Type [M0373928]
An allosteric enzyme that regulates glycolysis by catalyzing the transfer of a phosphate group from ATP to fructose-6-phosphate to yield fructose-1,6-bisphosphate. In humans, PHOSPHOFRUCTOKINASE-1 in muscle exists as the homotetramer of M subunits. Defects in this muscle enzyme cause GLYCOGEN STORAGE DISEASE TYPE VII, also known as Tarui's disease.

Phosphofructokinase-1, Type C [M0374833]
An allosteric enzyme that regulates glycolysis by catalyzing the transfer of a phosphate group from ATP to fructose-6-phosphate to yield fructose-1,6-bisphosphate. In the humans, 6-phosphofructose-1-kinase isozyme C is found in platelets, brain, heart, kidney, colon and testis. This isozyme C can exist as the homotetramer of C subunits (P subunits), or heterotetramer of C type and L type subunits.

Phosphofructokinase-2 [M0374774]
An allosteric enzyme that regulates glycolysis and gluconeogenesis by catalyzing the transfer of a phosphate group from ATP to fructose-6-phosphate to yield fructose-2,6-bisphosphate, an allosteric effector for the other 6-phosphofructokinase, PHOSPHOFRUCTOKINASE-1. Phosphofructokinase-2 is bifunctional: the dephosphorylated form is a kinase and the phosphorylated form is a phosphatase that breaks down fructose-2,6-bisphosphate to yield fructose-6-phosphate.

Phosphofructokinases [M0016668]
Allosteric enzymes that regulate glycolysis and gluconeogenesis. These enzymes catalyze phosphorylation of fructose-6-phosphate to either fructose-1,6-bisphosphate (PHOSPHOFRUCTOKINASE-1 reaction), or to fructose-2,6-bisphosphate (PHOSPHOFRUCTOKINASE-2 reaction).

Phosphoglucomutase [M0016669]
An enzyme that catalyzes the conversion of alpha D-glucose 1-phosphate to alpha D-glucose 6-phosphate. EC 5.4.2.2.

Phosphogluconate Dehydrogenase [M0016670]
An enzyme of the oxidoreductase class that catalyzes the reaction 6-phospho-D-gluconate and NADP+ to yield D-ribulose 5-phosphate, carbon dioxide, and NADPH. The reaction is a step in the pentose phosphate pathway of glucose metabolism. (From Dorland, 27th ed) EC 1.1.1.43.

Phosphoglycerate Dehydrogenase [M0262861]
An enzyme that catalyzes the oxidation of 3-phosphoglycerate to 3-phosphohydroxypyruvate. It takes part in the L-SERINE biosynthesis pathway.

Phosphoglycerate Kinase [M0016671]
An enzyme catalyzing the transfer of a phosphate group from 3-phospho-D-glycerate in the presence of ATP to yield 3-phospho-D-glyceroyl phosphate and ADP. EC 2.7.2.3.

Phosphoglycerate Mutase [M0016672]
An enzyme that catalyzes the conversion of 2-phospho-D-glycerate to 3-phospho-D-glycerate. EC 5.4.2.1.

Phosphohistone Phosphatase [M0016694]

Phospholipase A1 [M0016677]
A phospholipase that hydrolyzes the acyl group attached to the 1-position of PHOSPHOGLYCERIDES.

Phospholipase A2 [M0016678]
A phospholipase that hydrolyzes the acyl group attached to the 2-position of PHOSPHOGLYCERIDES.

Phospholipase C [M0016673]
An enzyme found in the alpha-toxin of Clostridium welchii and other strains of clostridia and bacilli. It hydrolyzes glycerophosphatidates with the formation of 1,2-diacylglycerol and a phosphorylated nitrogenous base such as choline. EC 3.1.4.3.

Phospholipase C gamma [M0225971]
A phospholipase C that is activated in response to growth factor stimulation and TYROSINE phosphorylation. Isoforms of this enzyme are critical for the generation of CALCIUM signals in HEMATOPOIETIC SYSTEMS in response to the stimulation of immune receptors.

Phospholipase C gamma 1 [M0225967]

Phospholipase C gamma 2 [M0225969]

Phospholipase C gamma D [M0225970]

Phospholipase D [M0016675]
An enzyme found mostly in plant tissue. It hydrolyzes glycerophosphatidates with the formation of a phosphatidic acid and a nitrogenous base such as choline. This enzyme also catalyzes transphosphatidylation reactions. EC 3.1.4.4.

Phospholipases [M0016676]
A class of enzymes that catalyze the hydrolysis of phosphoglycerides or glycerophosphatidates. EC 3.1.-.

Phospholipases A [M0016679]
Phospholipases that hydrolyze one of the acyl groups of phosphoglycerides or glycerophosphatidates. Phospholipase A1(EC 3.1.1.32) hydrolyzes the acyl group attached to the 1-position and phospholipase A2 (EC 3.1.1.4) hydrolyzes the acyl group attached to the 2-position.

Phospholipid Scramblase [M0476528]

Phospholipid Transfer Proteins [M0074935]
A ubiquitous family of proteins that transport PHOSPHOLIPIDS such as PHOSPHATIDYLINOSITOL and PHOSPHATIDYLCHOLINE between membranes. They play an important role in phospholipid metabolism during vesicular transport and SIGNAL TRANSDUCTION.

Phosphopeptides [M0016689]

Phosphoprotein Phosphatase [M0016695]
A group of enzymes removing the serine- or threonine-bound phosphate groups from a wide range of phosphoproteins, including a number of enzymes which have been phosphorylated under the action of a kinase. (Enzyme Nomenclature, 1992) EC 3.1.3.16.

Phosphoprotein Phosphatase-1 delta [M0016701]

Phosphoprotein Phosphatase-1 gamma 1 [M0016702]

Phosphoproteins [M0016705]

Phosphopyruvate Hydratase [M0016713]
An enzyme of the lyase class that catalyzes the dehydration of 2-phosphoglycerate to form phosphoenolpyruvate. (Dorland, 28th ed) EC 4.2.1.11.

Phosphoribosylaminoimidazolecarboxamide Formyltransferase [M0078323]
An enzyme that catalyzes the conversion of aminoimidazole-4-carboxamide ribonucleotide to 5-formyl-aminoimidazole-4-carboxamide ribonucleotide in the PURINE de novo synthesis pathway. It requires the cofactor N(10)-FORMYLTETRAHYDROFOLATE as the formyl donor.

Phosphoribosylglycinamide Formyltransferase [M0078358]
An enzyme that catalyzes the transfer of a formyl group from N10-formyltetrahydrofolate to N1-(5-phospho-D-ribosyl)glycinamide to yield N2-formyl-N1-(5-phospho-D-ribosyl)glycinamide and TETRAHYDROFOLATE. It plays a role in the de novo PURINE biosynthetic pathway.

Phosphoric Diester Hydrolases [M0016660]
A class of enzymes that catalyze the hydrolysis of one of the two ester bonds in a phosphodiester compound. EC 3.1.4.

Phosphoric Monoester Hydrolases [M0016683]
A group of hydrolases which catalyze the hydrolysis of monophosphoric esters with the production of one mole of orthophosphate. EC 3.1.3.

Phosphoric Triester Hydrolases [M0444858]
A class of enzymes that catalyze the hydrolysis of one of the three ester bonds in a phosphotriester-containing compound.

Phosphorus-Oxygen Lyases [M0029323]
Enzymes that catalyze the cleavage of a phosphorus-oxygen bond by means other than hydrolysis or oxidation. EC 4.6.

Phosphorylase a [M0016727]
The active form of GLYCOGEN PHOSPHORYLASE that is derived from the phosphorylation of PHOSPHORYLASE B. Phosphorylase a is deactivated via hydrolysis of phosphoserine by PHOSPHORYLASE PHOSPHATASE to form PHOSPHORYLASE B.

Phosphorylase b [M0016728]
The inactive form of GLYCOGEN PHOSPHORYLASE that is converted to the active form PHOSPHORYLASE A via phosphorylation by PHOSPHORYLASE KINASE and ATP.

Phosphorylase Kinase [M0016729]
An enzyme that catalyzes the conversion of ATP and phosphorylase b to ADP and phosphorylase a. EC 2.7.1.38.

Phosphorylase Phosphatase [M0016731]
An enzyme that deactivates glycogen phosphorylase a by releasing inorganic phosphate and phosphorylase b, the inactive form. EC 3.1.3.17.

Phosphorylases [M0009462]
A class of glucosyltransferases that catalyzes the degradation of storage polysaccharides, such as glucose polymers, by phosphorolysis in animals (GLYCOGEN PHOSPHORYLASE) and in plants (STARCH PHOSPHORYLASE).

Phosphoserine [M0016735]
The phosphoric acid ester of serine.

Phosphoseryl-Protein Phosphatase [M0016696]

Phosphothreonine [M0016736]
The phosphoric acid ester of threonine. Used as an identifier in the analysis of peptides, proteins, and enzymes.

Phosphotransferases [M0016737]
A rather large group of enzymes comprising not only those transferring phosphate but also diphosphate, nucleotidyl residues, and others. These have also been subdivided according to the acceptor group. (From Enzyme Nomenclature, 1992) EC 2.7.

Phosphotransferases (Alcohol Group Acceptor) [M0026976]
A group of enzymes that transfers a phosphate group onto an alcohol group acceptor. EC 2.7.1.

Phosphotransferases (Carboxyl Group Acceptor) [M0026974]
A class of enzymes that transfers phosphate groups and has a carboxyl group as an acceptor. EC 2.7.2.

Phosphotransferases (Nitrogenous Group Acceptor) [M0026975]
A group of enzymes that catalyzes the transfer of a phosphate group onto a nitrogenous group acceptor. EC 2.7.3.

Phosphotransferases (Paired Acceptors) [M0026995]
A group of enzymes that transfers two phosphate groups from a donor such as ATP to two different acceptors. (From Enzyme Nomenclature, 1992) EC 2.7.9.

Phosphotransferases (Phosphate Group Acceptor) [M0026979]
A group of enzymes that catalyzes the transfer of a phosphate group onto a phosphate group acceptor. EC 2.7.4.

Phosphotransferases (Phosphomutases) [M0027007]
A group of enzymes that catalyze an intramolecular transfer of a phosphate group. It has been shown in some cases that the enzyme has a functional phosphate group, which can act as the donor. These were previously listed under PHOSPHOTRANSFERASES (EC 2.7.-). (From Enzyme Nomenclature, 1992) EC 5.4.2.

Phosphotransferases, ATP [M0016738]

Phosphotyrosine [M0028374]
An amino acid that occurs in endogenous proteins. Tyrosine phosphorylation and dephosphorylation plays a role in cellular signal transduction and possibly in cell growth control and carcinogenesis.

Phosphotyrosyl Histone Phosphatase [M0025869]

Phosvitin [M0016741]
An egg yolk phosphoglycoprotein which contains about 90% of the yolk protein phosphorus. It is synthesized in the liver of the hen and transferred to the developing oocyte, where it is bound to lipoproteins within the yolk granules.

Photoreceptors, Microbial [M0029933]
Light absorbing proteins and protein prosthetic groups found in certain microorganisms. Some microbial photoreceptors initiate specific chemical reactions which signal a change in the environment, while others generate energy by pumping specific ions across a cellular membrane.

Photosynthetic Reaction Center Complex Proteins [M0447746]
Protein complexes that take part in the process of PHOTOSYNTHESIS. They are found in the THYLAKOID MEMBRANES of PLANTS and other photosynthetic organisms. There are two major complexes involved in the photosynthetic process called PHOTOSYSTEM I and PHOTOSYSTEM II.

Photosynthetic Reaction Center, Bacterial [M0024729]
A system consisting of proteins and cofactors which acts as a light-driven electron pump across the photosynthetic membrane of photosynthetic bacteria.

Photosynthetic Reaction Center, Plant [M0024721]
A system consisting of proteins and cofactors which facilitates light energy and electron transfer in plants.

Photosynthetic Reaction Centers [M0447902]

Photosystem I [M0447784]

Photosystem I Protein Complex [M0024722]
A large multisubunit protein complex that is found in the THYLAKOID MEMBRANE. It uses light energy derived from LIGHT-HARVESTING PROTEIN COMPLEXES to drive electron transfer reactions that result in either the reduction of NADP to NADPH or the transport of PROTONS across the membrane.

Photosystem II [M0447786]

Photosystem II Protein Complex [M0024723]
A large multisubunit protein complex found in the THYLAKOID MEMBRANE. It uses light energy derived from LIGHT-HARVESTING PROTEIN COMPLEXES to catalyze the splitting of WATER into DIOXYGEN and of reducing equivalents of HYDROGEN.

Photosystem II Reaction Center Complex D1 Protein [M0170005]

Photosystem II Reaction Center Complex D2 Protein [M0207896]

Phycobiliproteins [M0065798]
Light harvesting proteins found in phycobilisomes.

Phycocyanin [M0016771]
The metal-free blue phycobilin pigment in a conjugated chromoprotein of blue-green algae. It functions as light-absorbing substance together with chlorophylls.

Phycoerythrin [M0016773]
The metal-free red phycobilin pigment in a conjugated chromoprotein of red algae. It functions as a light-absorbing substance together with chlorophylls.

Physalaemin [M0016776]
An oligopeptide isolated from the skin of Physalaemus fuscumaculatus, a South American frog. It is a typical kinin, resembling SUBSTANCE P in structure and action and has been proposed as a sialagogue, antihypertensive, and vasodilator.

Phytochrome [M0016823]
A blue-green biliprotein widely distributed in the plant kingdom.

Phytochrome A [M0226198]
The primary plant photoreceptor responsible for perceiving and mediating responses to far-red light. It is a PROTEIN-SERINE-THREONINE KINASE that is translocated to the CELL NUCLEUS in response to light signals.

Phytochrome A3 [M0226195]

Phytochrome A4 [M0226197]

Phytochrome B [M0185924]
A plant photo regulatory protein that exists in two forms that are reversibly interconvertible by LIGHT. In response to light it moves to the CELL NUCLEUS and regulates transcription of target genes. Phytochrome B plays an important role in shade avoidance and mediates plant de-etiolation in red light.

Phytohemagglutinins [M0016824]
Mucoproteins isolated from the kidney bean (Phaseolus vulgaris); some of them are mitogenic to lymphocytes, others agglutinate all or certain types of erythrocytes or lymphocytes. They are used mainly in the study of immune mechanisms and in cell culture.

Phytomitogens [M0012279]

Phytourease [M0022317]

PI-3K Isotype p110 gamma [M0029502]

PIAS1 Protein Inhibitor of Activated STAT [M0479986]

PIAS2 Protein Inhibitor of Activated STAT [M0479990]

PIAS3 Protein Inhibitor of Activated STAT [M0479991]

PIAS4 Protein Inhibitor of Activated STAT [M0479993]

PII Nitrogen Regulatory Proteins [M0160770]
A family of signal transducing adaptor proteins that control the METABOLISM of NITROGEN. They are primarily found in prokaryotes.

PIN2 Protein [M0407292]
An alternatively spliced form of telomeric repeat binding protein 1. In human it lacks 20 amino acids.

Pit1 Sodium-Dependent Phosphate Symporter [M0466347]

Pit2 Sodium-Dependent Phosphate Symporter [M0225998]

Pitocin [M0373120]

Pitressin [M0022563]

Pituitary Adenylate Cyclase Activating Polypeptide 27 [M0456496]

Pituitary Adenylate Cyclase Activating Polypeptide 38 [M0456497]

Pituitary Adenylate Cyclase-Activating Polypeptide [M0173008]
A multi-function neuropeptide that acts throughout the body by elevating intracellular cyclic AMP level via its interaction with PACAP RECEPTORS. Although first isolated from hypothalamic extracts and named for its action on the pituitary, it is widely distributed in the central and peripheral nervous systems. PACAP is important in the control of endocrine and homeostatic processes, such as secretion of pituitary and gut hormones and food intake.

Pituitary Hormone Release Inhibiting Hormones [M0016913]
Polypeptide hormones produced in the hypothalamus which inhibit the release of pituitary hormones. Used for PHRIH in general or for which there is no specific heading.

Pituitary Hormone-Releasing Hormones [M0016916]
Peptides, natural or synthetic, that stimulate the release of PITUITARY HORMONES. They were first isolated from the extracts of the HYPOTHALAMUS; MEDIAN EMINENCE; PITUITARY STALK; and NEUROHYPOPHYSIS. In addition, some hypophysiotropic hormones control pituitary cell differentiation, cell proliferation, and hormone synthesis. Some can act on more than one pituitary hormone.

Pituitary Hormones, Anterior [M0016918]
Hormones secreted by the adenohypophysis (PITUITARY GLAND, ANTERIOR). Structurally, they include polypeptide, protein, and glycoprotein molecules.

Pituitary Hormones, Posterior [M0016919]
Hormones released from the neurohypophysis (PITUITARY GLAND, POSTERIOR). They include a number of peptides which are formed in the NEURONS in the HYPOTHALAMUS, bound to NEUROPHYSINS, and stored in the nerve terminals in the posterior pituitary. Upon stimulation, these peptides are released into the hypophysial portal vessel blood.

Placental Hormones [M0016941]
Hormones produced by the placenta include CHORIONIC GONADOTROPIN, and PLACENTAL LACTOGEN as well as steroids (ESTROGENS; PROGESTERONE), and neuropeptide hormones similar to those found in the hypothalamus (HYPOTHALAMIC HORMONES).

Placental Lactogen [M0016943]
A polypeptide hormone of approximately 25 kDa that is produced by the SYNCYTIOTROPHOBLASTS of the PLACENTA, also known as chorionic somatomammotropin. It has both GROWTH HORMONE and PROLACTIN activities on growth, lactation, and luteal steroid production. In women, placental lactogen secretion begins soon after implantation and increases to 1 g or more a day in late pregnancy. Placental lactogen is also an insulin antagonist.

Plakins [M0479544]
A family of related proteins that associate with cytoskeletal elements and junctional complexes at INTERCELLULAR JUNCTIONS. Plakins share a common plakin domain or a plakin repeat domain.

Plakophilin 1 [M0479610]

Plakophilin 2 [M0239807]

Plakophilin 2a [M0239808]

Plakophilin 2b [M0239809]

Plakophilin 3 [M0334927]

Plakophilins [M0239811]
Members of the armadillo family of proteins that are found in DESMOSOMES and interact with various proteins including desmocadherins; DESMOPLAKIN; ACTIN FILAMENTS; and KERATINS.

Plant Lectins [M0412051]
Protein or glycoprotein substances of plant origin that bind to sugar moieties in cell walls or membranes. Some carbohydrate-metabolizing proteins (ENZYMES) from PLANTS also bind to carbohydrates, however they are not considered lectins. Many plant lectins change the physiology of the membrane of BLOOD CELLS to cause agglutination, mitosis, or other biochemical changes. They may play a role in plant defense mechanisms.

Plant Proteins [M0016962]
Proteins found in plants (flowers, herbs, shrubs, trees, etc.). The concept does not include proteins found in vegetables for which VEGETABLE PROTEINS is available.

Plant Viral Movement Proteins [M0187871]
Viral proteins that facilitate the movement of viruses between plant cells by means of PLASMODESMATA, channels that traverse the plant cell walls.

Plasma Albumin [M0447123]

Plasma Factor VIII Complex [M0022849]

Plasma Kallikrein [M0328347]
A peptidohydrolytic enzyme that is formed from PREKALLIKREIN by FACTOR XIIA. It activates FACTOR XII; FACTOR VII; and PLASMINOGEN. It is selective for both ARGININE and to a lesser extent LYSINE bonds. EC 3.4.21.34.

Plasma Membrane Calcium-Transporting ATPase 1 [M0493889]

Plasma Membrane Calcium-Transporting ATPase 2 [M0249900]

Plasma Membrane Calcium-Transporting ATPase 3 [M0249901]

Plasma Membrane Calcium-Transporting ATPase 4 [M0249902]

Plasma Membrane Calcium-Transporting ATPases [M0249905]
Calcium-transporting ATPases found on the PLASMA MEMBRANE that catalyze the active transport of CALCIUM from the CYTOPLASM into the extracellular space. They play a role in maintaining a CALCIUM gradient across plasma membrane.

Plasma Membrane Neurotransmitter Transport Proteins [M0475594]
A family of neurotransmitter transporter proteins that facilitate NEUROTRANSMITTER reuptake into PRESYNAPTIC TERMINALS. They may play a role in regulating the intensity and duration of neurotransmission.

Plasma Prokallikrein A [M0017529]

Plasma Proteins [M0002711]

Plasma Transglutaminase [M0384136]
Despite the non-specific name it generally refers to Factor XIIIa. A few citations use the term nonspecif to state of activation.

Plasmin [M0008432]
A product of the lysis of plasminogen (profibrinolysin) by PLASMINOGEN activators. It is composed of two polypeptide chains, light (B) and heavy (A), with a molecular weight of 75,000. It is the major proteolytic enzyme involved in blood clot retraction or the lysis of fibrin and quickly inactivated by antiplasmins.

Plasminogen [M0016989]
Precursor of fibrinolysin (plasmin). It is a single-chain beta-globulin of molecular weight 80-90,000 found mostly in association with fibrinogen in plasma; plasminogen activators change it to fibrinolysin. It is used in wound debriding and has been investigated as a thrombolytic agent.

Plasminogen Activator Inhibitor 1 [M0026409]
A member of the serpin family of proteins. It inhibits both the tissue-type and urokinase-type plasminogen activators.

Plasminogen Activator Inhibitor 2 [M0026410]
Member of the serpin family of proteins. It inhibits both the tissue-type and urokinase-type plasminogen activators.

Plasminogen Activator Inhibitors, Endothelial [M0024269]

Plasminogen Activator Inhibitors, Placental [M0024270]

Plasminogen Activators [M0016994]
A heterogeneous group of proteolytic enzymes that convert PLASMINOGEN to PLASMIN. They are concentrated in the lysosomes of most cells and in the vascular endothelium, particularly in the vessels of the microcirculation.

Plasminogen Inactivators [M0024271]
Important modulators of the activity of plasminogen activators. Four inhibitors, all belonging to the serpin family of proteins, have been implicated in plasminogen activation inhibition. They are PAI-1; PAI-2; protease-nexin; and PROTEIN C INHIBITOR; (PAI-3). All inhibit both the tissue-type and urokinase-type plasminogen activators.

Plastocyanin [M0017005]
A copper-containing plant protein that is a fundamental link in the electron transport chain of green plants during the photosynthetic conversion of light energy by photophosphorylation into the potential energy of chemical bonds.

Plastoquinol-Plastocyanin Reductase [M0100020]
A component of the CYTOCHROME B6F COMPLEX, this enzyme catalyzes the oxidation of plastoquinol-1 to PLASTOQUINONE.

Platelet Factor 4 [M0017019]
A high-molecular-weight proteoglycan-platelet factor complex which is released from blood platelets by thrombin. It acts as a mediator in the heparin-neutralizing capacity of the blood and plays a role in platelet aggregation. At high ionic strength (I=0.75), the complex dissociates into the active component (molecular weight 29,000) and the proteoglycan carrier (chondroitin 4-sulfate, molecular weight 350,000). The molecule exists in the form of a dimer consisting of 8 moles of platelet factor 4 and 2 moles of proteoglycan.

Platelet Glycoprotein GPIb-IX Complex [M0028417]
Platelet membrane glycoprotein complex essential for normal platelet adhesion and clot formation at sites of vascular injury. It is composed of three polypeptides, GPIb alpha, GPIb beta, and GPIX. Glycoprotein Ib functions as a receptor for von Willebrand factor and for thrombin. Congenital deficiency of the GPIb-IX complex results in Bernard-Soulier syndrome. The platelet glycoprotein GPV associates with GPIb-IX and is also absent in Bernard-Soulier syndrome.

Platelet Glycoprotein GPIIb-IIIa Complex [M0028424]
Platelet membrane glycoprotein complex important for platelet adhesion and aggregation. It is an integrin complex containing INTEGRIN ALPHAIIB and INTEGRIN BETA3 which recognizes the arginine-glycine-aspartic acid (RGD) sequence present on several adhesive proteins. As such, it is a receptor for FIBRINOGEN; VON WILLEBRAND FACTOR; FIBRONECTIN; VITRONECTIN; and THROMBOSPONDINS. A deficiency of GPIIb-IIIa results in GLANZMANN THROMBASTHENIA.

Platelet Glycoproteins [M0017022]

Platelet Membrane Glycoprotein Ib [M0028418]

Platelet Membrane Glycoprotein IIb [M0028425]
Platelet membrane glycoprotein IIb is an integrin alpha subunit that heterodimerizes with INTEGRIN BETA3 to form PLATELET GLYCOPROTEIN GPIIB-IIIA COMPLEX. It is synthesized as a single polypeptide chain which is then postranslationally cleaved and processed into two disulfide-linked subunits of approximately 18 and 110 kDa in size.

Platelet Membrane Glycoprotein IX [M0028419]

Platelet Membrane Glycoprotein V [M0028420]

Platelet Membrane Glycoproteins [M0017021]
Surface glycoproteins on platelets which have a key role in hemostasis and thrombosis such as platelet adhesion and aggregation. Many of these are receptors.

Platelet Protein p235 [M0025327]

Platelet-activating Factor Acetylhydrolase IB [M0118403]

Platelet-Derived Growth Factor [M0017024]
Mitogenic peptide growth hormone carried in the alpha-granules of platelets. It is released when platelets adhere to traumatized tissues. Connective tissue cells near the traumatized region respond by initiating the process of replication.

Plectin [M0105731]
A cytoskeletal linker protein with a molecular weight of greater than 500 kDa. It binds INTERMEDIATE FILAMENTS; MICROTUBULES; and MICROFILAMENTS and plays a central role in the organization and stability of the CYTOSKELETON. Plectin is phosphorylated by CALMODULIN KINASE; PROTEIN KINASE A; and PROTEIN KINASE C.

PMS-Baclofen [M0454548]

PMS-Tryptophan [M0477044]

Pol1 Transcription Initiation Complex Proteins [M0407612]
Factors that form a preinitiation complex at promoters that are specifically transcribed by RNA POLYMERASE I.

Poly(A)-Binding Protein I [M0103429]
A poly(A) binding protein that has a variety of functions such as mRNA stabilization and protection of RNA from nuclease activity. Although poly(A) binding protein I is considered a major cytoplasmic RNA-binding protein it is also found in the CELL NUCLEUS and may be involved in transport of mRNP particles.

Poly(A)-Binding Protein II [M0103425]
A poly(A) binding protein that is involved in promoting the extension of the poly A tails of MRNA. The protein requires a minimum of ten ADENOSINE nucleotides in order for binding to mRNA. Once bound it works in conjunction with CLEAVAGE AND POLYADENYLATION SPECIFICITY FACTOR to stimulate the rate of poly A synthesis by POLY A POLYMERASE. Once poly-A tails reach around 250 nucleotides in length poly(A) binding protein II no longer stimulates POLYADENYLATION. Mutations within a GCG repeat region in the gene for poly(A) binding protein II have been shown to cause the disease MUSCULAR DYSTROPHY, OCULOPHARYNGEAL.

Poly(A)-Binding Proteins [M0103438]
Proteins that bind to the 3' polyadenylated region of MRNA. When complexed with RNA the proteins serve an array of functions such as stabilizing the 3' end of RNA, promoting poly(A) synthesis and stimulating mRNA translation.

Poly(ADP-ribose) Polymerases [M0017141]
Enzymes that catalyze the transfer of multiple ADP-RIBOSE groups from nicotinamide-adenine dinucleotide (NAD) onto protein targets, thus building up a linear or branched homopolymer of repeating ADP-ribose units i.e., POLY ADENOSINE DIPHOSPHATE RIBOSE.

Poly-(Alpha-L-Lysine) [M0017206]

Polyadenylation Factors [M0195407]

Polygalacturonase [M0017189]
A cell wall-degrading enzyme found in microorganisms and higher plants. It catalyzes the random hydrolysis of 1,4-alpha-D-galactosiduronic linkages in pectate and other galacturonans. EC 3.2.1.15.

Polygeline [M0017190]
A 3.5 per cent colloidal solution containing urea-cross-linked polymerized peptides. It has a molecular weight of approximately 35,000 and is prepared from gelatin and electrolytes. The polymeric solution is used as a plasma expander.

Polyglobin [M0011018]

Polyglutamate [M0017194]

Polyglutamic Acid [M0017193]
A peptide that is a homopolymer of glutamic acid.

Polyketide Synthase L1 [M0171390]

Polyketide Synthase WA [M0392968]

Polyketide Synthases [M0171396]
Large enzyme complexes composed of a number of component enzymes that are found in STREPTOMYCES which biosynthesize MACROLIDES and other polyketides.

Polylysine [M0017207]
A peptide which is a homopolymer of lysine.

Polymyxin B [M0017214]
A mixture of polymyxins B1 and B2, obtained from Bacillus polymyxa strains. They are basic polypeptides of about eight amino acids and have cationic detergent action on cell membranes. Polymyxin B is used for infections with gram-negative organisms, but may be neurotoxic and nephrotoxic.

Polymyxin B Sulfate [M0017213]

Polymyxin M [M0017216]

Polymyxins [M0017217]
Basic polypeptide antibiotic group obtained from Bacillus polymyxa. They affect the cell membrane by detergent action and may cause neuromuscular and kidney damage. At least eleven different members of the polymyxin group have been identified, each designated by a letter.

Polynucleosomes [M0015070]

Polynucleotide 5'-Hydroxyl-Kinase [M0017229]
An enzyme that catalyzes the transfer of a phosphate group to the 5'-terminal hydroxyl groups of DNA and RNA. EC 2.7.1.78.

Polynucleotide Adenylyltransferase [M0017138]
An enzyme that catalyzes the synthesis of polyadenylic acid from ATP. May be due to the action of RNA polymerase (EC 2.7.7.6) or polynucleotide adenylyltransferase (EC 2.7.7.19). EC 2.7.7.19.

Polynucleotide Ligases [M0017231]
Catalyze the joining of preformed ribonucleotides or deoxyribonucleotides in phosphodiester linkage during genetic processes. EC 6.5.1.

Polyomavirus T Proteins [M0001443]

Polypeptide Hormones [M0409649]

Polypeptide VP1, Structural [M0024032]

Polypeptides [M0456187]

Polyproteins [M0017889]
Proteins which are synthesized as a single polymer and then cleaved into several distinct proteins.

Polypyrimidine Tract-Binding Protein [M0190270]
A RNA-binding protein that binds to polypyriminidine rich regions in the INTRONS of messenger RNAs. Polypyrimidine tract-binding protein may be involved in regulating the ALTERNATIVE SPLICING of mRNAs since its presence on an intronic RNA region that is upstream of an EXON inhibits the splicing of the exon into the final mRNA product.

Polyribonucleotide Nucleotidyltransferase [M0017230]
An enzyme of the transferase class that catalyzes the reaction RNA(n+1) and orthophosphate to yield RNA(n) and a nucleoside diphosphate, or the reverse reaction. ADP, IDP, GDP, UDP, and CDP can act as donors in the latter case. (From Dorland, 27th ed) EC 2.7.7.8.

Polysaccharide-Lyases [M0017248]
A group of carbon-oxygen lyases. These enzymes catalyze the breakage of a carbon-oxygen bond in polysaccharides leading to an unsaturated product and the elimination of an alcohol. EC 4.2.2.

Polysialoglycoproteins [M0019813]

Polyubiquitin [M0184920]
An oligomer formed from the repetitive linking of the C-terminal glycine of one UBIQUITIN molecule via an isopeptide bond to a lysine residue on a second ubiquitin molecule. It is structurally distinct from UBIQUITIN C, which is a single protein containing a tandemly arrayed ubiquitin peptide sequence.

POR-8 [M0373870]

Porcine Intestinal Heptacosapeptide [M0016233]

Pore Forming Cytotoxic Proteins [M0490137]
Proteins secreted from an organism which form membrane-spanning pores in target cells to destroy them. This is in contrast to PORINS and MEMBRANE TRANSPORT PROTEINS that function within the synthesizing organism and COMPLEMENT immune proteins. These pore forming cytotoxic proteins are a form of primitive cellular defense which are also found in human LYMPHOCYTES.

Pore Proteins [M0027503]

Porins [M0027502]
Porins are protein molecules that were originally found in the outer membrane of GRAM-NEGATIVE BACTERIA and that form multi-meric channels for the passive DIFFUSION of WATER; IONS; or other small molecules. Porins are present in bacterial CELL WALLS, as well as in plant, fungal, mammalian and other vertebrate CELL MEMBRANES and MITOCHONDRIAL MEMBRANES.

Porphobilinogen Synthase [M0000953]
An enzyme that catalyzes the formation of porphobilinogen from two molecules of 5-aminolevulinic acid. EC 4.2.1.24.

Positive Transcriptional Elongation Factor B [M0265832]
A transcriptional elongation factor complex that is comprised of a heterodimer of CYCLIN-DEPENDENT KINASE 9 and one of several CYCLINS including cyclin T1, T2 and K. It functions by phosphorylating the carboxy-terminal domain (CTD) of RNA POLYMERASE II, which results in more processive transcription complexes.

Postacton [M0373044]

Potassium Channels [M0023384]
Cell membrane glycoproteins that are selectively permeable to potassium ions. At least eight major groups of K channels exist and they are made up of dozens of different subunits.

Potassium Channels, Calcium-Activated [M0371394]
Potassium channels whose activation is dependent on intracellular calcium concentrations.

Potassium Channels, Inwardly Rectifying [M0371374]
Potassium channels where the flow of K+ ions into the cell is greater than the outward flow.

Potassium Channels, Tandem Pore Domain [M0371430]
Potassium channels that contain two pores in tandem. They are responsible for baseline or leak currents and may be the most numerous of all K channels.

Potassium Channels, Voltage-Gated [M0371348]
Potassium channel whose permeability to ions is extremely sensitive to the transmembrane potential difference. The opening of these channels is induced by the membrane depolarization of the ACTION POTENTIAL.

Potassium Glutamate [M0009377]

Potassium Magnesium Asparaginate [M0017383]

Potassium Magnesium Aspartate [M0017384]
An intra-extracellular electrolyte exchange agent with a variety of effects.

Potassium-Hydrogen Antiporters [M0110471]
Membrane proteins that allow the exchange of hydrogen ions for potassium ions across the cellular membrane. The action of these antiporters influences intracellular pH and potassium ion homeostasis.

POU Domain Factors [M0208075]
A family of transcription factors characterized by the presence of a bipartite DNA-binding domain known as the POU domain. The POU domain contains two subdomains, a POU-specific domain and a POU-homeodomain. The POU domain was originally identified as a region of approximately 150 amino acids shared between the Pit-1, Oct-1, Oct-2, and Unc-86 transcription factors.

pp85 gag-fes [M0024048]

PPAR alpha [M0199111]
A nuclear transcription factor. Heterodimerization with RETINOID X RECEPTOR GAMMA is important to metabolism of LIPIDS. It is the target of FIBRATES to control HYPERLIPIDEMIAS.

PPAR delta [M0199113]
A nuclear transcription factor. It is activated by PROSTACYCLIN.

PPAR gamma [M0199114]
A nuclear transcription factor. Heterodimerization with RETINOID X RECEPTOR ALPHA is important in regulation of GLUCOSE metabolism and CELL GROWTH PROCESSES. It is a target of THIAZOLIDINEDIONES for control of DIABETES MELLITUS.

PPAR-beta [M0199109]
One of the PPAR nuclear transcription factors.

PPARgamma2 [M0457738]

PPARgamma3 [M0199116]

Prealbumin [M0017446]
A tetrameric protein, molecular weight between 50,000 and 70,000, consisting of 4 equal chains, and migrating on electrophoresis in 3 fractions more mobile than serum albumin. Its concentration ranges from 7 to 33 per cent in the serum, but levels decrease in liver disease.

Precipitins [M0017455]
Antibodies which elicit IMMUNOPRECIPITATION when combined with antigen.

Precolicin E1 [M0004761]

Pregnancy Proteins [M0017484]
Proteins produced by organs of the mother or the PLACENTA during PREGNANCY. These proteins may be pregnancy-specific (present only during pregnancy) or pregnancy-associated (present during pregnancy or under other conditions such as hormone therapy or certain malignancies.)

Pregnancy-Associated alpha 2-Macroglobulins [M0447960]
Large (>160 kDa) glycoproteins with electrophoretic mobility of ALPHA-GLOBULINS, found in high concentration in the plasma of pregnant women but also in a number of species including mouse, rat, and others (ALPHA-MACROGLOBULINS). In humans, they are always present in the circulation and are nonspecific inhibitors of PROTEINASES, similar to COMPLEMENT PROTEINS (C3; C4; C5).

Pregnancy-Associated Plasma Protein B [M0461394]

Pregnancy-Associated Plasma Protein C [M0461396]

Pregnancy-Associated Plasma Protein-A [M0017493]
A product of the PLACENTA, and DECIDUA, secreted into the maternal circulation during PREGNANCY. It has been identified as an IGF binding protein (IGFBP)-4 protease that proteolyzes IGFBP-4 and thus increases IGF bioavailability. It is found also in human FIBROBLASTS, ovarian FOLLICULAR FLUID, and GRANULOSA CELLS. The enzyme is a heterotetramer of about 500-kDa.

Pregnancy-Specific beta 1-Glycoproteins [M0017495]
Glycoproteins with the electrophoretic mobility of BETA-GLOBULINS, secreted by the placental TROPHOBLASTS into the maternal bloodstream during PREGNANCY. They can be detected 18 days after OVULATION and reach 200 mg/ml at the end of pregnancy. They are associated with fetal well-being.

Pregnant Mare Serum Gonadotropins [M0417712]

Pregnyl [M0009546]

Prekallikrein [M0017530]
A plasma protein which is the precursor of kallikrein. Plasma that is deficient in prekallikrein has been found to be abnormal in thromboplastin formation, kinin generation, evolution of a permeability globulin, and plasmin formation. The absence of prekallikrein in plasma leads to Fletcher factor deficiency, a congenital disease.

Prephenate Dehydratase [M0017552]
An enzyme that catalyzes the conversion of prephenate to phenylpyruvate with the elimination of water and carbon dioxide. In the enteric bacteria this enzyme also possesses chorismate mutase activity, thereby catalyzing the first two steps in the biosynthesis of phenylalanine. EC 4.2.1.51.

Prephenate Dehydrogenase [M0017554]
An enzyme that catalyzes the conversion of prephenate to p-hydroxyphenylpyruvate in the presence of NAD. In the enteric bacteria, this enzyme also possesses chorismate mutase activity, thereby catalyzing the first two steps in the biosynthesis of tyrosine. EC 1.3.1.12.

Preproendothelin-1 [M0167677]

Preproglucagon [M0097238]

Preprorenin [M0082816]

Pres iv [M0485301]

Presenilin-1 [M0248671]
Integral membrane protein of Golgi and endoplasmic reticulum. Its homodimer is an essential component of the gamma-secretase complex that catalyzes the cleavage of membrane proteins such as NOTCH RECEPTORS and AMYLOID BETA-PROTEIN precursors. PSEN1 mutations cause early-onset ALZHEIMER DISEASE type 3 that may occur as early as 30 years of age in humans.

Presenilin-2 [M0257716]
Integral membrane protein of Golgi and endoplasmic reticulum. Its homodimer is an essential component of the gamma-secretase complex that catalyzes the cleavage of membrane proteins such as NOTCH RECEPTORS and AMYLOID BETA-PROTEIN precursors. PSEN2 mutations cause ALZHEIMER DISEASE type 4.

Presenilins [M0496221]
Integral membrane proteins and essential components of the gamma-secretase complex that catalyzes the cleavage of membrane proteins such as NOTCH RECEPTORS and AMYLOID BETA-PROTEIN precursors. Mutations of presenilins lead to presenile ALZHEIMER DISEASE with onset before age 65 years.

Pressimmune [M0001468]

Prinivil [M0373301]

Prions [M0017586]
Small proteinaceous infectious particles which resist inactivation by procedures that modify NUCLEIC ACIDS and contain an abnormal isoform of a cellular protein which is a major and necessary component. The abnormal (scrapie) isoform is PrPSc (PRPSC PROTEINS) and the cellular isoform PrPC (PRPC PROTEINS). The primary amino acid sequence of the two isoforms is identical. Human diseases caused by prions include CREUTZFELDT-JAKOB SYNDROME; GERSTMANN-STRAUSSLER SYNDROME; and INSOMNIA, FATAL FAMILIAL.

Pristinamycin [M0375364]
An antibiotic mixture originally isolated from Streptomyces pristinaspiralis. It is a mixture of compounds from STREPTOGRAMIN GROUP A: pristinamycin IIA and IIB and from STREPTOGRAMIN GROUP B: pristinamycin IA, pristinamycin IB, pristinamycin IC.

Pristinamycin IIB [M0374411]
Pristinamycin IIB is identical to Streptogramin A except that it lacks a double bond at the 2,3-position of the pyrroline moiety of the compound.

Pro alpha 1 Collagen [M0017622]

Pro alpha 2 Collagen [M0017623]

Pro-Apolipoprotein A-I [M0117573]

Pro-Apolipoprotein A-II [M0140943]

Pro-Matrix Metalloproteinase-1 [M0251545]

Pro-Opiomelanocortin [M0017593]
A 30-kDa protein synthesized primarily in the ANTERIOR PITUITARY GLAND and the HYPOTHALAMUS. It is also found in the skin and other peripheral tissues. Depending on species and tissues, POMC is cleaved by PROHORMONE CONVERTASES yielding various active peptides including ACTH; BETA-LIPOTROPIN; ENDORPHINS; MELANOCYTE-STIMULATING HORMONES; and others (GAMMA-LPH; CORTICOTROPIN-LIKE INTERMEDIATE LOBE PEPTIDE; N-terminal peptide of POMC or NPP).

Pro-Opiomelanocortin Converting Enzyme [M0103951]

Procarboxypeptidase A [M0092192]

Procarboxypeptidase A1 [M0289902]

Procarboxypeptidase A2 [M0285035]

Procarboxypeptidase B [M0129225]

Procarboxypeptidase U [M0368256]

Procaspase 7 [M0377554]

Procaspase-1 [M0295647]

Procaspase-2 [M0386488]

Procaspase-3 [M0296643]

Procaspase-8 [M0360985]

Procaspase-9 [M0296645]

Procholeragenoid [M0004250]
Detoxified aggregate of cholera toxin formed by heat treatment of purified cholera toxin.

Procollagen [M0017624]
A biosynthetic precursor of collagen containing additional amino acid sequences at the amino-terminal and carboxyl-terminal ends of the polypeptide chains.

Procollagen N-Endopeptidase [M0017631]
An extracellular endopeptidase which excises a block of peptides at the amino terminal, nonhelical region of the procollagen molecule with the formation of collagen. Absence or deficiency of the enzyme causes accumulation of procollagen which results in the inherited connective tissue disorder--dermatosparaxis. EC 3.4.24.14.

Procollagen Type I [M0017630]

Procollagen Type II [M0017625]

Procollagen Type IV [M0017627]

Procollagen Type IX [M0372058]

Procollagen Type M [M0017628]

Procollagen Type V [M0017629]

Procollagen Type VI [M0372056]

Procollagen Type VII [M0372055]

Procollagen Type X [M0372059]

Procollagen Type XI [M0372060]

Procollagen Type XII [M0372061]

Procollagen Type XIII [M0372062]

Procollagen Type XVIII [M0442532]

Procollagen-Lysine, 2-Oxoglutarate 5-Dioxygenase [M0012838]
A mixed-function oxygenase that catalyzes the hydroxylation of peptidyllysine, usually in protocollagen, to peptidylhydroxylysine. The enzyme utilizes molecular oxygen with concomitant oxidative decarboxylation of the cosubstrate 2-oxoglutarate to succinate. EC 1.14.11.4.

Procollagen-Proline Dioxygenase [M0017694]
A mixed-function oxygenase that catalyzes the hydroxylation of a prolyl-glycyl-containing-peptide, usually in protocollagen, to a hydroxyprolylglycyl-containing-peptide. The enzyme utilizes molecular oxygen with a concomitant oxidative decarboxylation of 2-oxoglutarate to succinate. EC 1.14.11.2.

Proendothelin (1-38) [M0174536]
A 38 amino acid form of endothelin-1 that results from alternative processing of proendothelin-1.

Profezim [M0020691]

Profilin 1 [M0366972]

Profilin 2 [M0063581]

Profilin 3 [M0398501]

Profilin 4 [M0480099]

Profilins [M0063582]
A family of low molecular weight proteins that bind ACTIN and control actin polymerization. They are found in eukaryotes and are ubiquitously expressed.

Progesterone Reductase [M0017673]
An enzyme that catalyzes the reduction of a 3 beta-hydroxy-delta(5)-steroid to 3-oxo-delta(4)-steroid in the presence of NAD. It converts pregnenolone to progesterone and dehydroepiandrosterone to androstenedione. EC 1.1.1.145.

Progesterone-Binding Globulin [M0017674]
A glycoprotein migrating as alpha 1-globulin, molecular weight 70,000 to 120,000. The protein, which is present in increased amounts in the plasma during pregnancy, binds mainly progesterone, with other steroids including testosterone competing weakly.

Proglucagon [M0086289]
The common precursor polypeptide of pancreatic GLUCAGON and intestinal GLUCAGON-LIKE PEPTIDES. Proglucagon is the 158-amino acid segment of preproglucagon without the N-terminal signal sequence. Proglucagon is expressed in the PANCREAS; INTESTINES; and the CENTRAL NERVOUS SYSTEM. Posttranslational processing of proglucagon is tissue-specific yielding numerous bioactive peptides.

Proglumide [M0017675]
A drug that exerts an inhibitory effect on gastric secretion and reduces gastrointestinal motility. It is used clinically in the drug therapy of gastrointestinal ulcers.

Prohormone Convertases [M0449281]

Proinsulin [M0017685]
A pancreatic polypeptide of about 110 amino acids, depending on the species, that is the precursor of insulin. Proinsulin, produced by the PANCREATIC BETA CELLS, is comprised sequentially of the N-terminal B-chain, the proteolytically removable connecting C-peptide, and the C-terminal A-chain. It also contains three disulfide bonds, two between A-chain and B-chain. After cleavage at two locations, insulin and C-peptide are the secreted products. Intact proinsulin with low bioactivity also is secreted in small amounts.

Prokaryotic Initiation Factor-1 [M0419356]
The smallest of the three prokaryotic initiation factors with a molecular size of approximately 8 kD. It binds near the A-site of the 30S subunit of RIBOSOMES and may play a role in preventing premature addition of aminoacyl-tRNA-linked PEPTIDE ELONGATION FACTOR TU to the ribosome during the initiation of a peptide chain (PEPTIDE CHAIN INITIATION, TRANSLATIONAL).

Prokaryotic Initiation Factor-2 [M0176255]
The largest of the three prokaryotic initiation factors with a molecular size of approximately 80 kD. It functions in the transcription initiation process by promoting the binding of formylmethionine-tRNA to the P-site of the 30S ribosome and by preventing the incorrect binding of elongator tRNA to the translation initiation site.

Prokaryotic Initiation Factor-3 [M0078903]
A prokaryotic initiation factor that plays a role in recycling of ribosomal subunits for a new round of translational initiation. It binds to 16S RIBOSOMAL RNA and stimulates the dissociation of vacant 70S ribosomes. It may also be involved in the preferential binding of initiator tRNA to the 30S initiation complex.

Prokaryotic Initiation Factors [M0419376]
Peptide initiation factors from prokaryotic organisms. Only three factors are needed for translation initiation in prokaryotic organisms, which occurs by a far simpler process than in PEPTIDE CHAIN INITIATION, TRANSLATIONAL of eukaryotic organisms.

Prolactin [M0017689]
A lactogenic hormone secreted by the adenohypophysis (PITUITARY GLAND, ANTERIOR). It is a polypeptide of approximately 23 kD. Besides its major action on lactation, in some species prolactin exerts effects on reproduction, maternal behavior, fat metabolism, immunomodulation and osmoregulation. Prolactin receptors are present in the mammary gland, hypothalamus, liver, ovary, testis, and prostate.

Prolactin Release-Inhibiting Factors [M0017690]
A number of peptides with inhibitory activities on PROLACTIN release have been isolated from the HYPOTHALAMUS, the peripheral nervous system, and the gut. These include SOMATOSTATIN, and peptides derived from POMC and precursor for VASOPRESSIN-ASSOCIATED NEUROPHYSIN. Biogenic amine DOPAMINE is also a potent PIF.

Prolastin [M0372282]

Proliferating Cell Nuclear Antigen [M0028162]
Nuclear antigen with a role in DNA synthesis, DNA repair, and cell cycle progression. PCNA is required for the coordinated synthesis of both leading and lagging strands at the replication fork during DNA replication. PCNA expression correlates with the proliferation activity of several malignant and non-malignant cell types.

Proline [M0017693]
A non-essential amino acid that is synthesized from GLUTAMIC ACID. It is an essential component of COLLAGEN and is important for proper functioning of joints and tendons.

Proline Oxidase [M0017695]
The first enzyme of the proline degradative pathway. It catalyzes the oxidation of proline to pyrroline-5-carboxylic acid in the presence of oxygen and water. The action is not reversible. The specific activity of proline oxidase increases with age. EC 1.5.3.-.

Proline-Directed Protein Kinases [M0175907]
A subclass of protein serine-threonine kinases that phosphorylate proteins on a SERINE or THREONINE residue that is immediately preceding a PROLINE residue.

Pronase [M0017731]
A proteolytic enzyme obtained from Streptomyces griseus.

Pronase E [M0017732]

Pronase P [M0017733]

Propanediol Dehydratase [M0017741]
An enzyme that catalyzes the dehydration of 1,2-propanediol to propionaldehyde. EC 4.2.1.28.

Properdin [M0017748]
A 53-kDa protein that is a positive regulator of the alternate pathway of complement activation (COMPLEMENT ACTIVATION PATHWAY, ALTERNATIVE). It stabilizes the ALTERNATIVE PATHWAY C3 CONVERTASE (C3bBb) and protects it from rapid inactivation, thus facilitating the cascade of COMPLEMENT ACTIVATION and the formation of MEMBRANE ATTACK COMPLEX. Individuals with mutation in the PFC gene exhibit properdin deficiency and have a high susceptibility to infections.

Properdin Factor Bf [M0017751]

Properdin Factor Bf F1 [M0017752]

Proprotein Convertase 1 [M0103931]
A CALCIUM-dependent endopeptidase that has specificity for cleavage at ARGININE that is near paired basic residues. It cleaves a variety of prohormones including PRO-OPIOMELANOCORTIN; PRORENIN; proenkephalins; prodynorphin; prosomatostatin; and PROINSULIN.

Proprotein Convertase 2 [M0183722]
A serine endopeptidase that has specificity for cleavage at ARGININE. It cleaves a variety of prohormones including PRO-OPIOMELANOCORTIN, proluteinizing-hormone-releasing hormone, proenkephalins, prodynorphin, and PROINSULIN.

Proprotein Convertase 5 [M0219516]
A serine endopeptidase found primarily in the EXTRACELLULAR MATRIX. It has specificity for cleavage of a variety of substrates including PRORENIN, pro-membrane type-1 matrix metalloproteinase, and NEURAL CELL ADHESION MOLECULE L1.

Proprotein Convertases [M0449043]
Proteolytic enzymes that are involved in the conversion of protein precursors such as peptide prohormones into PEPTIDE HORMONES. Some are ENDOPEPTIDASES, some are EXOPEPTIDASES.

Prorenin [M0061608]

Prostaglandin-Endoperoxide Synthases [M0017803]
Enzyme complexes that catalyze the formation of PROSTAGLANDINS from the appropriate unsaturated FATTY ACIDS, molecular OXYGEN, and a reduced acceptor.

Prostate-Specific Antigen [M0026444]
A glycoprotein that is a kallikrein-like serine proteinase and an esterase, produced by epithelial cells of both normal and malignant prostate tissue. It is an important marker for the diagnosis of prostate cancer.

Prostatic Secretory Proteins [M0384976]
Proteins secreted by the prostate gland. The major secretory proteins from the human prostate gland include PROSTATE-SPECIFIC ANTIGEN, prostate-specific acid phosphatase, prostate-specific membrane antigen, and prostate-specific protein-94.

Protamine Chloride [M0017842]

Protamine Kinase [M0010421]
An aspect of protein kinase (EC 2.7.1.37) in which serine residues in protamines and histones are phosphorylated in the presence of ATP. EC 2.7.1.70.

Protamine Sulfate [M0017843]

Protamines [M0017844]
A group of simple proteins that yield basic amino acids on hydrolysis and that occur combined with nucleic acid in the sperm of fish. Protamines contain very few kinds of amino acids. Protamine sulfate combines with heparin to form a stable inactive complex; it is used to neutralize the anticoagulant action of heparin in the treatment of heparin overdose. (From Merck Index, 11th ed; Martindale, The Extra Pharmacopoeia, 30th ed, p692)

Protease La [M0095049]
A prokaryotic ATP-dependent protease that plays a role in the degradation of many abnormal proteins. It is a tetramer of 87-kDa subunits, each of which contains a proteolytic site and a ATP-binding site.

Protease VII [M0020692]

Proteasome Endopeptidase Complex [M0140424]
A large multisubunit complex that plays an important role in the degradation of most of the cytosolic and nuclear proteins in eukaryotic cells. It contains a 700-kDa catalytic sub-complex and two 700-kDa regulatory sub-complexes. The complex digests ubiquitinated proteins and protein activated via ornithine decarboxylase antizyme.

Protein C [M0017852]
A vitamin-K dependent zymogen present in the blood, which, upon activation by thrombin and thrombomodulin exerts anticoagulant properties by inactivating factors Va and VIIIa at the rate-limiting steps of thrombin formation.

Protein C Inhibitor [M0027231]
A member of the serpin family of proteins that is found in plasma and urine. It is dependent on heparin and able to inhibit activated protein C, thrombin, kallikrein, and other SERINE ENDOPEPTIDASES.

Protein D-Aspartate-L-Isoaspartate Methyltransferase [M0122971]
A PROTEIN O-METHYLTRANSFERASE that recognizes and catalyzes the methyl esterification of ISOASPARTIC ACID and D-ASPARTIC ACID residues in peptides and proteins. It initiates the repair of proteins damaged by the spontaneous decomposition of normal L-aspartic acid and L-asparagine residues.

Protein Disulfide Reductase (Glutathione) [M0017857]
An enzyme that catalyzes the reduction of a protein-disulfide in the presence of glutathione, forming a protein-dithiol. Insulin is one of its substrates. EC 1.8.4.2.

Protein Disulfide-Isomerase [M0029260]
An enzyme that catalyzes the rearrangement of disulfide bonds within proteins during folding. It is a monomer identical to one of the subunits of PROCOLLAGEN-PROLINE DIOXYGENASE. (From Dorland, 28th ed) EC 5.3.4.1.

Protein Hydrolysates [M0017860]

Protein Inducer MGI [M0004824]

Protein Inhibitors of Activated STAT [M0478067]
A family of structurally related proteins that are constitutively expressed and that negatively regulate cytokine-mediated SIGNAL TRANSDUCTION PATHWAYS. PIAS proteins inhibit the activity of SIGNAL TRANSDUCERS AND ACTIVATORS OF TRANSCRIPTION.

Protein Isoforms [M0029740]
Different forms of a protein that may be produced from different GENES, or from the same gene by ALTERNATIVE SPLICING.

Protein Kinase C [M0017861]
An serine-threonine protein kinase that requires the presence of physiological concentrations of CALCIUM and membrane PHOSPHOLIPIDS. The additional presence of DIACYLGLYCEROLS markedly increases its sensitivity to both calcium and phospholipids. The sensitivity of the enzyme can also be increased by PHORBOL ESTERS and it is believed that protein kinase C is the receptor protein of tumor-promoting phorbol esters.

Protein Kinase C-alpha [M0233036]
A cytoplasmic serine threonine kinase involved in regulating CELL DIFFERENTIATION and CELLULAR PROLIFERATION. Overexpression of this enzyme has been shown to promote PHOSPHORYLATION of BCL-2 PROTO-ONCOGENE PROTEINS and chemoresistance in human acute leukemia cells.

Protein Kinase C-delta [M0217909]
A ubiquitously expressed protein kinase that is involved in a variety of cellular SIGNAL PATHWAYS. Its activity is regulated by a variety of signaling protein tyrosine kinase.

Protein Kinase C-epsilon [M0234611]
A protein kinase C subtype that was originally characterized as a CALCIUM-independent, serine-threonine kinase that is activated by PHORBOL ESTERS and DIACYLGLYCEROLS. It is targeted to specific cellular compartments in response to extracellular signals that activate G-PROTEIN-COUPLED RECEPTORS; TYROSINE KINASE RECEPTORS; and intracellular protein tyrosine kinase.

Protein Kinase M [M0017862]

Protein Kinase Type II, Cyclic AMP-Dependent [M0026999]

Protein Kinases [M0017869]
A family of enzymes that catalyze the conversion of ATP and a protein to ADP and a phosphoprotein. EC 2.7.1.37.

Protein Methyltransferases [M0017871]
Enzymes that catalyze the methylation of amino acids after their incorporation into a polypeptide chain. S-Adenosyl-L-methionine acts as the methylating agent. EC 2.1.1.

Protein Phosphatase C-I [M0016697]

Protein Phosphatase C-II [M0016698]

Protein Phosphatase G [M0009468]

Protein Phosphatase H-II [M0016699]

Protein Phosphatase-1 alpha [M0016703]

Protein Phosphatase-1 gamma 2 [M0016704]

Protein Phosphatase-1G [M0016700]

Protein Precursors [M0017873]

Protein S [M0026253]
The vitamin K-dependent cofactor of activated PROTEIN C. Together with protein C, it inhibits the action of factors VIIIa and Va. A deficiency in protein S; (PROTEIN S DEFICIENCY); can lead to recurrent venous and arterial thrombosis.

Protein Sorting Signals [M0352619]
Amino acid sequences found in transported proteins that selectively guide the distribution of the proteins to specific cellular compartments.

Protein Subunits [M0351591]
Single chains of amino acids that are the units of multimeric PROTEINS. Multimeric proteins can be composed of identical or non-identical subunits. One or more monomeric subunits may compose a protomer which itself is a subunit structure of a larger assembly.

Protein-Lysine 6-Oxidase [M0012851]
An enzyme oxidizing peptidyl-lysyl-peptide in the presence of water & molecular oxygen to yield peptidyl-allysyl-peptide plus ammonia & hydrogen peroxide. EC 1.4.3.13.

Protein-Serine-Threonine Kinases [M0026339]
A group of enzymes that catalyzes the phosphorylation of serine or threonine residues in proteins, with ATP or other nucleotides as phosphate donors.

Protein-Tyrosine Kinases [M0017888]
Protein kinases that catalyze the PHOSPHORYLATION of TYROSINE residues in proteins with ATP or other nucleotides as phosphate donors.

Protein-Tyrosine-Phosphatase [M0025868]
An enzyme group that specifically dephosphorylates phosphotyrosyl residues in selected proteins. Together with PROTEIN-TYROSINE KINASE, it regulates tyrosine phosphorylation and dephosphorylation in cellular signal transduction and may play a role in cell growth control and carcinogenesis. EC 3.1.3.48.

Proteinase Inhibitory Peptides, Secretory [M0493736]

Proteinase Inhibitory Proteins, Secretory [M0493685]
Peptides and proteins found in BODILY SECRETIONS and BODY FLUIDS that are PROTEASE INHIBITORS. They play a role in INFLAMMATION, tissue repair and innate immunity (IMMUNITY, INNATE) by inhibiting endogenous proteinases such as those produced by LEUKOCYTES and exogenous proteases such as those produced by invading microorganisms.

Proteins [M0017890]
Linear POLYPEPTIDES that are synthesized on RIBOSOMES and may be further modified, crosslinked, cleaved, or assembled into complex proteins with several subunits. The specific sequence of AMINO ACIDS determines the shape the polypeptide will take, during PROTEIN FOLDING, and the function of the protein.

Proteins, Recombinant DNA [M0018642]

Proteochondroitin Sulfate [M0017893]

Proteochondroitin Sulfates [M0017894]
Proteoglycans found in cartilage. They consist of several chondroitin sulfate molecules linked to protein(s) by neutral sugar linkage regions.

Proteoglycan Type H [M0017896]

Proteoglycans [M0017897]
Glycoproteins which have a very high polysaccharide content.

Proteolipids [M0017898]
Protein-lipid combinations abundant in brain tissue, but also present in a wide variety of animal and plant tissues. In contrast to lipoproteins, they are insoluble in water, but soluble in a chloroform-methanol mixture. The protein moiety has a high content of hydrophobic amino acids. The associated lipids consist of a mixture of GLYCEROPHOSPHATES; CEREBROSIDES; and SULFOGLYCOSPHINGOLIPIDS; while lipoproteins contain PHOSPHOLIPIDS; CHOLESTEROL; and TRIGLYCERIDES.

Proteome [M0328053]
The protein complement of an organism coded for by its genome.

Proteozym [M0463231]

Prothrombin [M0017904]
A plasma protein that is the inactive precursor of thrombin. It is converted to thrombin by a prothrombin activator complex consisting of factor Xa, factor V, phospholipid, and calcium ions. Deficiency of prothrombin leads to hypoprothrombinemia.

Protilase [M0474985]

Protirelin Tartrate (1:1) [M0329663]

Proto-Oncogene Protein c-crk-1 [M0180675]

Proto-Oncogene Protein c-crk-2 [M0259688]

Proto-Oncogene Protein c-crk-3 [M0477438]

Proto-Oncogene Protein c-ets-1 [M0139271]
An ets proto-oncogene expressed primarily in adult LYMPHOID TISSUE; BRAIN; and VASCULAR ENDOTHELIAL CELLS.

Proto-Oncogene Protein c-ets-2 [M0172600]
A ubiquitously expressed ets proto-oncogene protein that may play a role in regulation of CELL PROLIFERATION and CELL DIFFERENTIATION.

Proto-Oncogene Protein c-fli-1 [M0215273]
A member of the c-ets family of transcription factors that is preferentially expressed in cells of hematopoietic lineages and vascular endothelial cells. It was originally identified as a protein that provides a retroviral integration site for integration of FRIEND MURINE LEUKEMIA VIRUS.

Proto-Oncogene Protein p21(c-Ha-ras) [M0024888]

Proto-Oncogene Protein p21(c-Ki-ras) [M0024889]

Proto-Oncogene Protein p21(c-N-ras) [M0024890]

Proto-Oncogene Protein p59(fyn) [M0164671]

Proto-Oncogene Protein p60(fyn) [M0164681]

Proto-Oncogene Protein p72(fyn) [M0164675]

Proto-Oncogene Proteins [M0017909]
Products of proto-oncogenes. Normally they do not have oncogenic or transforming properties, but are involved in the regulation or differentiation of cell growth. They often have protein kinase activity.

Proto-Oncogene Proteins A-raf [M0029572]
A raf kinase subclass expressed primarily in non-neuronal tissues such as SKELETAL MUSCLE. The A-raf kinases are MAP kinase kinase kinases that have specificity for MAP KINASE KINASE 1.

Proto-Oncogene Proteins B-raf [M0029573]
A raf kinase subclass found at high levels in neuronal tissue. The B-raf Kinases are MAP kinase kinase kinases that have specificity for MAP KINASE KINASE 1 and MAP KINASE KINASE 2.

Proto-Oncogene Proteins c-abl [M0024934]
Non-receptor tyrosine kinases encoded by the c-abl gene. They are distributed in both the cytoplasm and the nucleus. c-Abl plays a role in normal hematopoiesis especially of the myeloid lineage. Oncogenic transformation of c-abl arises when specific N-terminal amino acids are deleted, releasing the kinase from negative regulation.

Proto-Oncogene Proteins c-akt [M0150739]
A protein-serine-threonine kinase that is activated by PHOSPHORYLATION in response to GROWTH FACTORS or INSULIN. It plays a major role in cell metabolism, growth, and survival as a core component of SIGNAL TRANSDUCTION. Three isoforms have been described in mammalian cells.

Proto-Oncogene Proteins c-akt1 [M0283975]

Proto-Oncogene Proteins c-akt2 [M0479108]

Proto-Oncogene Proteins c-akt3 [M0479107]

Proto-Oncogene Proteins c-bcl-2 [M0028673]
Membrane proteins encoded by the BCL-2 GENES and serving as potent inhibitors of cell death by APOPTOSIS. The proteins are found on mitochondrial, microsomal, and NUCLEAR MEMBRANE sites within many cell types. Overexpression of bcl-2 proteins, due to a translocation of the gene, is associated with follicular lymphoma.

Proto-Oncogene Proteins c-bcl-6 [M0222844]
A DNA-binding protein that represses GENETIC TRANSCRIPTION of target genes by recruiting HISTONE DEACETYLASES. Aberrant Blc-6 expression is associated with certain types of human B-CELL LYMPHOMA.

Proto-Oncogene Proteins c-bcr [M0155533]
Proto-oncogene protein bcr is a serine-threonine kinase that functions as a negative regulator of CELL PROLIFERATION and NEOPLASTIC CELL TRANSFORMATION. It is commonly fused with cellular abl protein to form BCR-ABL FUSION PROTEINS in PHILADELPHIA CHROMOSOME positive LEUKEMIA patients.

Proto-Oncogene Proteins c-cbl [M0188097]
Proto-oncogene proteins that negatively regulate RECEPTOR PROTEIN-TYROSINE KINASE signaling. It is a UBIQUITIN-PROTEIN LIGASE and the cellular homologue of ONCOGENE PROTEIN V-CBL.

Proto-Oncogene Proteins c-crk [M0180679]
Signal transducing adaptor proteins that contain SRC HOMOLOGY DOMAINS and play a role in CYTOSKELETON reorganization. c-crk protein is closely related to ONCOGENE PROTEIN V-CRK and includes several alternatively spliced isoforms.

Proto-Oncogene Proteins c-ets [M0139274]
A family of transcription factors that share a unique DNA-binding domain. The name derives from viral oncogene-derived protein ONCOGENE PROTEIN V-ETS of the AVIAN ERYTHROBLASTOSIS VIRUS.

Proto-Oncogene Proteins c-fes [M0144743]
Proto-oncogene proteins fes are protein-tyrosine kinases with a central SH2 DOMAIN. It has been implicated in SIGNAL TRANSDUCTION PATHWAYS for CELL DIFFERENTIATION of a variety of cell types including MYELOID PROGENITOR CELLS. Fes proto-oncogene proteins also bind TUBULIN and promotes MICROTUBULE assembly.

Proto-Oncogene Proteins c-fos [M0025542]
Cellular DNA-binding proteins encoded by the c-fos genes (GENES, FOS). They are involved in growth-related transcriptional control. c-fos combines with c-jun (PROTO-ONCOGENE PROTEINS C-JUN) to form a c-fos/c-jun heterodimer (TRANSCRIPTION FACTOR AP-1) that binds to the TRE (TPA-responsive element) in promoters of certain genes.

Proto-Oncogene Proteins c-fyn [M0164682]
Src-family kinases that associate with T-CELL ANTIGEN RECEPTOR and phosphorylate a wide variety of intracellular signaling molecules.

Proto-Oncogene Proteins c-hck [M0184546]
Members of the src-family tyrosine kinase family that are strongly expressed in MYELOID CELLS and B-LYMPHOCYTES.

Proto-Oncogene Proteins c-jun [M0025512]
Cellular DNA-binding proteins encoded by the c-jun genes (GENES, JUN). They are involved in growth-related transcriptional control. There appear to be three distinct functions: dimerization (with c-fos), DNA-binding, and transcriptional activation. Oncogenic transformation can take place by constitutive expression of c-jun.

Proto-Oncogene Proteins c-kit [M0028387]
A protein-tyrosine kinase receptor that is specific for STEM CELL FACTOR. This interaction is crucial for the development of hematopoietic, gonadal, and pigment stem cells. Genetic mutations that disrupt the expression of PROTO-ONCOGENE PROTEINS C-KIT are associated with PIEBALDISM, while overexpression or constitutive activation of the c-kit protein-tyrosine kinase is associated with tumorigenesis.

Proto-Oncogene Proteins c-maf [M0227896]
Maf proto-oncogene protein is the major cellular homolog of the V-MAF ONCOGENE PROTEIN. It was the first mammalian MAF TRANSCRIPTION FACTOR identified, and it is induced in activated T-LYMPHOCYTES and regulates GENETIC TRANSCRIPTION of INTERLEUKIN-4. c-maf is frequently translocated to an immunoglobulin locus in MULTIPLE MYELOMA.

Proto-Oncogene Proteins c-mdm2 [M0187954]
An E3 UBIQUITIN LIGASE that interacts with and inhibits TUMOR SUPPRESSOR PROTEIN P53. Its ability to ubiquitinate p53 is regulated by TUMOR SUPPRESSOR PROTEIN P14ARF.

Proto-Oncogene Proteins c-met [M0029482]
Cell surface protein-tyrosine kinase receptors for HEPATOCYTE GROWTH FACTOR. They consists of an extracellular alpha chain which is disulfide-linked to the transmembrane beta chain. The cytoplasmic portion contains the catalytic domain and sites critical for the regulation of kinase activity. Mutations of the gene for PROTO-ONCOGENE PROTEINS C-MET are associated with papillary renal carcinoma and other neoplasia.

Proto-Oncogene Proteins c-mos [M0026143]
Cellular proteins encoded by the c-mos genes (GENES, MOS). They function in the cell cycle to maintain MATURATION PROMOTING FACTOR in the active state and have protein-serine/threonine kinase activity. Oncogenic transformation can take place when c-mos proteins are expressed at the wrong time.

Proto-Oncogene Proteins c-myb [M0328560]
Cellular DNA-binding proteins encoded by the myb gene (GENES, MYB). They are expressed in a wide variety of cells including thymocytes and lymphocytes, and regulate cell differentiation. Overexpression of myb is associated with autoimmune diseases and malignancies.

Proto-Oncogene Proteins c-myc [M0024867]
Cellular DNA-binding proteins encoded by the c-myc genes. They are normally involved in nucleic acid metabolism and in mediating the cellular response to growth factors. Elevated and deregulated (constitutive) expression of c-myc proteins can cause tumorigenesis.

Proto-Oncogene Proteins c-pim-1 [M0154312]
Serine-threonine protein kinases that relay signals from CYTOKINE RECEPTORS and are involved in control of CELL GROWTH PROCESSES; CELL DIFFERENTIATION; and APOPTOSIS.

Proto-Oncogene Proteins c-raf [M0029578]
A ubiquitously expressed raf kinase subclass that plays an important role in SIGNAL TRANSDUCTION. The c-raf Kinases are MAP kinase kinase kinases that have specificity for MAP KINASE KINASE 1 and MAP KINASE KINASE 2.

Proto-Oncogene Proteins c-rel [M0328561]
Cellular DNA-binding proteins encoded by the rel gene (GENES, REL). They are expressed predominately in hematopoietic cells and may play a role in lymphocyte differentiation. Rel frequently combines with other related proteins (NF-KAPPA B, I-kappa B, relA) to form heterodimers that regulate transcription. Rearrangement or overexpression of c-rel can cause tumorigenesis.

Proto-Oncogene Proteins c-ret [M0166929]
Receptor protein-tyrosine kinases involved in the signaling of GLIAL CELL-LINE DERIVED NEUROTROPHIC FACTOR ligands. They contain an extracellular cadherin domain and form a receptor complexes with GDNF RECEPTORS. Mutations in ret protein are responsible for HIRSCHSPRUNG DISEASE and MULTIPLE ENDOCRINE NEOPLASIA TYPE 2.

Proto-Oncogene Proteins c-sis [M0328562]
Cellular DNA-binding proteins encoded by the sis gene (GENES, SIS). c-sis proteins make up the B chain of PLATELET-DERIVED GROWTH FACTOR. Overexpression of c-sis causes tumorigenesis.

Proto-Oncogene Proteins c-vav [M0185911]
Proto-oncogene proteins that are guanine nucleotide exchange factors for RHO GTPASES. They also function as signal transducing adaptor proteins.

Proto-Oncogene Proteins c-yes [M0146934]
Members of the src-family tyrosine kinases that are activated during the transition from G2 PHASE to M PHASE of the CELL CYCLE. It is highly homologous to PROTO-ONCOGENE PROTEIN PP60(C-SRC).

Proto-Oncogene Proteins p21(ras) [M0024891]
Cellular proteins encoded by the H-ras, K-ras and N-ras genes. The proteins have GTPase activity and is involved in signal transduction as a monomeric GTP-binding proteins. Elevated levels of p21 c-ras have been associated with neoplasia. This enzyme was formerly listed as EC 3.6.1.47.

Proto-Oncogene Proteins pp60(c-src) [M0025073]
Membrane-associated tyrosine-specific kinases encoded by the c-src genes. They have an important role in cellular growth control. Truncation of carboxy-terminal residues in pp60(c-src) leads to PP60(V-SRC) which has the ability to transform cells. This kinase pp60 c-src should not be confused with csk, also known as c-src kinase.

Protocatechuate-3,4-Dioxygenase [M0017911]
An enzyme that catalyzes the oxidation of protocatechuate to 3-carboxy-cis-cis-muconate in the presence of molecular oxygen. It contains ferric ion. EC 1.13.11.3.

Protocollagen [M0371210]
A precursor of procollagen consisting of procollagen peptide chains in which proline and lysine have not yet been hydroxylated.

Protomers [M0412212]
Substructures of multimeric PROTEINS. They may be monomeric or heterodimeric substructures.

Proton Pumps [M0026545]
Integral membrane proteins that transport protons across a membrane. This transport can be linked to the hydrolysis of ADENOSINE TRIPHOSPHATE. What is referred to as proton pump inhibitors frequently is about POTASSIUM HYDROGEN ATPASE.

Proton-Phosphate Symporters [M0381411]
Proteins that cotransport hydrogen ions and phosphate ions across cellular membranes.

Proton-Translocating ATPase, F0 Sector [M0009728]
The transmembrane region of proton-translocating ATPase complexes. It contains three subunits named a, b and c.

Proton-Translocating ATPase, F1 Sector [M0009720]
The catalytic sector of proton-translocating ATPase complexes. It contains five subunits named alpha, beta, gamma, delta and eta.

Proton-Translocating ATPases [M0009723]
Multisubunit enzymes that reversibly synthesize ADENOSINE TRIPHOSPHATE. They are coupled to the transport of protons across a membrane.

Protophan [M0011442]

Protoporphyrinogen Oxidase [M0078571]
A membrane-bound flavoenzyme that catalyzes the oxygen-dependent aromatization of PROTOPORPHYRINOGEN IX (Protogen) to protoporphyrin IX (Proto IX). It is the last enzyme of the common branch of the HEME and CHLOROPHYLL pathways in plants, and is the molecular target of diphenyl ether-type herbicides. VARIEGATE PORPHYRIA is an autosomal dominant disorder associated with deficiency of protoporphyrinogen oxidase.

Protozoan Proteins [M0024201]
Proteins found in any species of protozoan.

Protyreline [M0494446]

PrP (CJD) [M0027908]

PrP (GSS) [M0027909]

PrP 27-30 Protein [M0027911]
Protease-resistant core of PrPSC, the abnormal isoform of prion proteins (PRIONS). PrP 27-30 is produced by limited proteolysis of the N-terminus of PrPSc.

PrPC Proteins [M0027910]
Normal cellular isoform of prion proteins (PRIONS) encoded by a chromosomal gene and found in normal and scrapie-infected brain tissue, and other normal tissue. PrPC are protease-sensitive proteins whose function is unknown. Posttranslational modification of PrPC into PrPSC leads to infectivity.

PrPSc Proteins [M0027906]
Abnormal isoform of prion proteins (PRIONS) resulting from a posttranslational modification of the cellular prion protein (PRPC PROTEINS). PrPSc are disease-specific proteins seen in certain human and animal neurodegenerative diseases (PRION DISEASES).

Pseudo Arylsulfatase A [M0001781]

Pseudocholinesterase [M0017943]
An aspect of cholinesterases.

Pseudoglobulins [M0019697]

PTEN Phosphohydrolase [M0479128]
A lipid phosphatase that acts on phosphatidylinositol-3,4,5-trisphosphate to regulate various SIGNAL TRANSDUCTION PATHWAYS. It modulates CELL GROWTH PROCESSES; CELL MIGRATION; and APOPTOSIS. Mutations in PTEN are associated with COWDEN DISEASE and PROTEUS SYNDROME as well as NEOPLASTIC CELL TRANSFORMATION.

PTPase 1B [M0025870]

Pulmin [M0011914]

Pulmonary Surfactant-Associated Protein A [M0097367]
An abundant pulmonary surfactant-associated protein that binds to a variety of lung pathogens, resulting in their opsinization. It also stimulates MACROPHAGES to undergo PHAGOCYTOSIS of microorganisms. Surfactant protein A contains a N-terminal collagen-like domain and a C-terminal lectin domain that are characteristic of members of the collectin family of proteins.

Pulmonary Surfactant-Associated Protein B [M0163656]
A pulmonary surfactant associated-protein that plays an essential role in alveolar stability by lowering the surface tension at the air-liquid interface. Inherited deficiency of pulmonary surfactant-associated protein B is one cause of RESPIRATORY DISTRESS SYNDROME, NEWBORN.

Pulmonary Surfactant-Associated Protein C [M0175888]
A pulmonary surfactant associated protein that plays a role in alveolar stability by lowering the surface tension at the air-liquid interface. It is a membrane-bound protein that constitutes 1-2% of the pulmonary surfactant mass. Pulmonary surfactant-associated protein C is one of the most hydrophobic peptides yet isolated and contains an alpha-helical domain with a central poly-valine segment that binds to phospholipid bilayers.

Pulmonary Surfactant-Associated Protein D [M0175313]
An abundant pulmonary surfactant-associated protein that binds to a variety of lung pathogens and enhances their opsinization and killing by phagocytic cells. Surfactant protein D contains a N-terminal collagen-like domain and a C-terminal lectin domain that are characteristic of members of the collectin family of proteins.

Pulmonary Surfactant-Associated Proteins [M0097373]
Proteins found in the LUNG that act as PULMONARY SURFACTANTS.

Puregon [M0211976]

Purine-Nucleoside Phosphorylase [M0018164]
An enzyme that catalyzes the reaction between a purine nucleoside and orthophosphate to form a free purine plus ribose-5-phosphate. EC 2.4.2.1.

Pyocin [M0018212]

Pyocin 1-4 [M0018201]

Pyocin 103 [M0018202]

Pyocin F 1 [M0018203]

Pyocin F 2 [M0018204]

Pyocin F 3 [M0018205]

Pyocin P 3 [M0018206]

Pyocin R [M0018207]

Pyocin R 2 [M0018209]

Pyocin R1 [M0018208]

Pyocin S 2 [M0018210]

Pyocins [M0018211]
Bacteriocins elaborated by mutant strains of Pseudomonas aeruginosa. They are protein or protein-lipopolysaccharide complexes lethal to other strains of the same or related species.

Pyostacine [M0475728]

Pyridoxal Kinase [M0018241]
An enzyme that catalyzes reversibly the phosphorylation of pyridoxal in the presence of ATP with the formation of pyridoxal 5-phosphate and ADP. Pyridoxine, pyridoxamine and various derivatives can also act as acceptors. EC 2.7.1.35.

Pyridoxaminephosphate Oxidase [M0018244]
An enzyme catalyzing the deamination of pyridoxaminephosphate to pyridoxal phosphate. It is a flavoprotein that also oxidizes pyridoxine-5-phosphate and pyridoxine. EC 1.4.3.5.

Pyridoxine-5-Phosphate Oxidase [M0018245]

Pyroglobulins [M0018269]
Atypical gamma immunoglobulins characterized by their irreversible heat denaturation at 56-degrees C. Pyroprecipitation is inhibited at pH below 3 and above 9. The presence of pyroglobulins in the serum is the cause of pyroglobulinemia. They are frequently present in multiple myeloma and the pyroglobulin precipitate binds complement, reacts with rheumatoid factor, produces passive cutaneous anaphylaxis, generalized passive anaphylaxis and passive Arthus-type phenomena.

Pyroglutamate [M0018281]

Pyroglutamate Hydrolase [M0018271]
Hydrolyzes pyroglutamic acid in the presence of ATP to glutamate plus ADP and inorganic phosphate. Deficiency leads to pyroglutamic acidurea.

Pyroglutamyl-Peptidase I [M0018270]
An enzyme that catalyzes the release of a N-terminal pyroglutamyl group from a polypeptide provided the next residue is not proline. It is inhibited by thiol-blocking reagents and occurs in mammalian tissues, microorganisms, and plants. (From Enzyme Nomenclature, 1992) EC 3.4.19.3.

Pyrophosphatases [M0018274]
A group of enzymes within the class EC 3.6.1.- that catalyze the hydrolysis of diphosphate bonds, chiefly in nucleoside di- and triphosphates. They may liberate either a mono- or diphosphate. EC 3.6.1.-.

Pyrrolidonecarboxylic Acid [M0018279]
A cyclized derivative of L-GLUTAMIC ACID. Elevated blood levels may be associated with problems of GLUTAMINE or GLUTATHIONE metabolism.

Pyrroline Carboxylate Reductases [M0018282]
A group of enzymes that catalyze the reduction of 1-pyrroline carboxylate to proline in the presence of NAD(P)H. Includes both the 2-oxidoreductase (EC 1.5.1.1) and the 5-oxidoreductase (EC 1.5.1.2). The former also reduces 1-piperidine-2-carboxylate to pipecolate and the latter also reduces 1-pyrroline-3-hydroxy-5-carboxylate to hydroxyproline.

Pyruvate Carboxylase [M0018288]
A biotin-dependent enzyme belonging to the ligase family that catalyzes the addition of CARBON DIOXIDE to pyruvate. It is occurs in both plants and animals. Deficiency of this enzyme causes severe psychomotor retardation and ACIDOSIS, LACTIC in infants. EC 6.4.1.1.

Pyruvate Decarboxylase [M0018289]
Catalyzes the decarboxylation of an alpha keto acid to an aldehyde and carbon dioxide. Thiamine pyrophosphate is an essential cofactor. In lower organisms, which ferment glucose to ethanol and carbon dioxide, the enzyme irreversibly decarboxylates pyruvate to acetaldehyde. EC 4.1.1.1.

Pyruvate Dehydrogenase (Lipoamide) [M0115762]
The E1 component of the multienzyme PYRUVATE DEHYDROGENASE COMPLEX. It is composed of 2 alpha subunits (pyruvate dehydrogenase E1 alpha subunit) and 2 beta subunits (pyruvate dehydrogenase E1 beta subunit).

Pyruvate Dehydrogenase (Lipoamide)-Phosphatase [M0018292]
(Pyruvate dehydrogenase (lipoamide))-phosphate phosphohydrolase. A mitochondrial enzyme that catalyzes the hydrolytic removal of a phosphate on a specific seryl hydroxyl group of pyruvate dehydrogenase, reactivating the enzyme complex. EC 3.1.3.43.

Pyruvate Dehydrogenase Complex [M0018291]
A multienzyme complex responsible for the formation of ACETYL COENZYME A from pyruvate. The enzyme components are PYRUVATE DEHYDROGENASE (LIPOAMIDE); dihydrolipoamide acetyltransferase; and LIPOAMIDE DEHYDROGENASE. Pyruvate dehydrogenase complex is subject to three types of control: inhibited by acetyl-CoA and NADH; influenced by the energy state of the cell; and inhibited when a specific serine residue in the pyruvate decarboxylase is phoshorylated by ATP. PYRUVATE DEHYDROGENASE (LIPOAMIDE)-PHOSPHATASE catalyzes reactivation of the complex. (From Concise Encyclopedia Biochemistry and Molecular Biology, 3rd ed)

Pyruvate Kinase [M0018293]
ATP:pyruvate 2-O-phosphotransferase. A phosphotransferase that catalyzes reversibly the phosphorylation of pyruvate to phosphoenolpyruvate in the presence of ATP. It has four isozymes (L, R, M1, and M2). Deficiency of the enzyme results in hemolytic anemia. EC 2.7.1.40.

Pyruvate Kinase L [M0018294]

Pyruvate Oxidase [M0018299]

Pyruvate Synthase [M0078625]
A ferredoxin-containing enzyme that catalyzes the COENZYME A-dependent oxidative decarboxylation of PYRUVATE to acetyl-COENZYME A and CARBON DIOXIDE.

Pyruvate, Orthophosphate Dikinase [M0018300]
An enzyme that catalyzes the reaction of ATP, pyruvate, and orthophosphate to form AMP plus phosphoenolpyruvate plus pyrophosphate. EC 2.7.9.1.

Q beta Replicase [M0018307]
An enzyme that catalyzes the replication of the RNA of coliphage Q beta. EC 2.7.7.-.

Q-SNARE Proteins [M0477189]
SNARE proteins in which the central amino acid residue of the SNARE motif is a GLUTAMINE. They are classified separately from the R-SNARE PROTEINS where the central amino acid residue of the SNARE motif is an ARGININE. Subfamilies, the QA-SNARES; QB-SNARES; and QC-SNARES are grouped by the position of their SNARE motif-containing-domains in the SNARE complex and by their sequence similarities.

Qa-SNARE Proteins [M0477190]
A subfamily of Q-SNARE PROTEINS which occupy the same position as syntaxin 1A in the SNARE complex and which also are most similar to syntaxin 1A in their AMINO ACID SEQUENCE. This subfamily is also known as the syntaxins, although a few so called syntaxins are Qc-SNARES.

Qb-SNARE Proteins [M0477191]
A subfamily of Q-SNARE PROTEINS which occupy the same position in the SNARE complex as the N-terminal SNARE domain of SNAP-25 and which also are most similar to the N-terminal region of SNAP-25 in their AMINO ACID SEQUENCE.

Qc-SNARE Proteins [M0477192]
A subfamily of Q-SNARE PROTEINS which occupy the same position in the SNARE complex as the C-terminal SNARE domain of SNAP-25 and which also are most similar to the C-terminal region of SNAP-25 in their AMINO ACID SEQUENCE.

Quinone Reductases [M0018355]
NAD(P)H:(quinone acceptor) oxidoreductases. A family that includes three enzymes which are distinguished by their sensitivity to various inhibitors. EC 1.6.99.2 (NAD(P)H DEHYDROGENASE (QUINONE);) is a flavoprotein which reduces various quinones in the presence of NADH or NADPH and is inhibited by dicoumarol. EC 1.6.99.5 (NADH dehydrogenase (quinone)) requires NADH, is inhibited by AMP and 2,4-dinitrophenol but not by dicoumarol or folic acid derivatives. EC 1.6.99.6 (NADPH dehydrogenase (quinone)) requires NADPH and is inhibited by dicoumarol and folic acid derivatives but not by 2,4-dinitrophenol.

Quisqualate [M0024937]

Quisqualate Receptor [M0027287]

Quisqualic Acid [M0024938]
An agonist at two subsets of excitatory amino acid receptors, ionotropic receptors that directly control membrane channels and metabotropic receptors that indirectly mediate calcium mobilization from intracellular stores. The compound is obtained from the seeds and fruit of Quisqualis chinensis.

R-Binder [M0021779]

R-SNARE Proteins [M0477194]
SNARE proteins where the central amino acid residue of the SNARE motif is an ARGININE. They are classified separately from the Q-SNARE PROTEINS where the central amino acid residue of the SNARE motif is a GLUTAMINE. This subfamily contains the vesicle associated membrane proteins (VAMPs) based on similarity to the prototype for the R-SNAREs, VAMP2 (synaptobrevin 2).

R-Type Pyruvate Kinase [M0018298]

rab GTP-Binding Proteins [M0328226]
A large family of MONOMERIC GTP-BINDING PROTEINS that play a key role in cellular secretory and endocytic pathways. EC 3.6.1.-.

rab1 GTP-Binding Proteins [M0328229]
A genetically related subfamily of RAB GTP-BINDING PROTEINS involved in vesicle transport between the ENDOPLASMIC RETICULUM and the GOLGI APPARATUS and through early Golgi compartments. This enzyme was formerly listed as EC 3.6.1.47.

rab1A GTP-Binding Protein [M0208615]

rab2 GTP-Binding Protein [M0328234]
A protein involved in transport between the ENDOPLASMIC RETICULUM and the GOLGI APPARATUS. This enzyme was formerly listed as EC 3.6.1.47.

rab3 GTP-Binding Proteins [M0328235]
A genetically related subfamily of RAB GTP-BINDING PROTEINS involved in calcium-dependent EXOCYTOSIS. This enzyme was formerly listed as EC 3.6.1.47.

rab3A GTP-Binding Protein [M0328236]
The most abundant member of the RAB3 GTP-BINDING PROTEINS. It is involved in calcium-dependent EXOCYTOSIS and is localized to neurons and neuroendocrine cells. This enzyme was formerly listed as EC 3.6.1.47.

rab4 GTP-Binding Proteins [M0328238]
A genetically related subfamily of RAB GTP-BINDING PROTEINS involved in recycling of proteins such as cell surface receptors from early endosomes to the cell surface. This enzyme was formerly listed as EC 3.6.1.47.

rab4A GTP-Binding Protein [M0190414]

rab5 GTP-Binding Proteins [M0328239]
A genetically related subfamily of RAB GTP-BINDING PROTEINS involved in transport from the cell membrane to early endosomes. This enzyme was formerly listed as EC 3.6.1.47.

rab5A GTP-Binding Protein [M0185755]

rac GTP-Binding Proteins [M0328240]
A sub-family of RHO GTP-BINDING PROTEINS that is involved in regulating the organization of cytoskeletal filaments. This enzyme was formerly listed as EC 3.6.1.47.

rac1 GTP-Binding Protein [M0328243]
A rac GTP-binding protein involved in regulating actin filaments at the plasma membrane. It controls the development of filopodia and lamellipodia in cells and thereby influences cellular motility and adhesion. It is also involved in activation of NADPH OXIDASE. This enzyme was formerly listed as EC 3.6.1.47.

Racemases [M0029703]

Racemases and Epimerases [M0029704]
Enzymes that catalyze inversion of the configuration around an asymmetric carbon in a substrate having one (racemase) or more (epimerase) center(s) of asymmetry. (Dorland, 28th ed) EC 5.1.

Racemethionine [M0013577]

Racemetirosine [M0373730]

Rad51 Recombinase [M0201275]
A Rec A recombinase found in eukaryotes. Rad51 is involved in DNA REPAIR of double-strand breaks.

Rad52 DNA Repair and Recombination Protein [M0221369]
A DNA-binding protein that mediates DNA REPAIR of double strand break, and GENETIC RECOMBINATION.

raf Kinases [M0461520]
A family of closely-related serine-threonine kinases that were originally identified as the cellular homologs of the retrovirus-derived V-RAF KINASES. They are MAP kinase kinase kinases that play important roles in SIGNAL TRANSDUCTION.

ral A Protein [M0219065]
Cannot add RN: EC 3.6.1.-

ral GTP-Binding Proteins [M0328244]
A family of ubiquitously expressed MONOMERIC GTP-BINDING PROTEINS that are involved in intracellular signal transduction. This enzyme was formerly listed as EC 3.6.1.47.

ral Guanine Nucleotide Exchange Factor [M0328245]
A guanine nucleotide exchange factor that stimulates the dissociation of GDP from RAL GTP-BINDING PROTEINS. It also has GDP exchange activity towards other MONOMERIC GTP-BINDING PROTEINS.

ran GTP-Binding Protein [M0328246]
A monomeric GTP-binding protein involved in nucleocytoplasmic transport of proteins into the nucleus and RNA into the cytoplasm. This enzyme was formerly listed as EC 3.6.1.47.

Random Peptide Library [M0028554]

RANK Ligand [M0281676]
A transmembrane protein belonging to the tumor necrosis factor superfamily that specifically binds RECEPTOR ACTIVATOR OF NUCLEAR FACTOR-KAPPA B and OSTEOPROTEGERIN. It plays an important role in regulating OSTEOCLAST differentiation and activation.

RANTES [M0028315]
A chemokine that is a chemoattractant for eosinophils, monocytes, and lymphocytes. It is a potent and selective eosinophil chemotaxin that is stored in and released from platelets and activated T-cells.

RANTES Protein, Murine [M0028316]

rap GTP-Binding Proteins [M0328247]
A family of MONOMERIC GTP-BINDING PROTEINS that are related to RAS PROTEINS.This enzyme was formerly listed as EC 3.6.1.47.

rap1 GTP-Binding Protein [M0328961]

rap1 GTP-Binding Proteins [M0328248]
A genetically related subfamily of RAP GTP-BINDING PROTEINS that share homology with RAS PROTEINS. They bind to Ras effectors but do not activate them, therefore they may antagonize the effects of RAS PROTEINS. This enzyme was formerly listed as EC 3.6.1.47.

Rapamycin Binding Proteins [M0356483]

Rapicidin [M0022197]

ras GTPase-Activating Proteins [M0328251]
PROTEINS that specifically activate the GTP-phosphohydrolase activity of RAS PROTEINS.

ras Guanine Nucleotide Exchange Factors [M0328252]
A family of GUANINE NUCLEOTIDE EXCHANGE FACTORS that are specific for RAS PROTEINS.

ras Proteins [M0027924]
Small, monomeric GTP-binding proteins encoded by ras genes (GENES, RAS). The protooncogene-derived protein, PROTO-ONCOGENE PROTEIN P21(RAS), plays a role in normal cellular growth, differentiation and development. The oncogene-derived protein (ONCOGENE PROTEIN P21(RAS)) can play a role in aberrant cellular regulation during neoplastic cell transformation (CELL TRANSFORMATION, NEOPLASTIC). This enzyme was formerly listed as EC 3.6.1.47.

ras-GRF1 [M0328255]
A guanine nucleotide exchange factor that is expressed primarily in neuronal tissue and may be specific for the Ha-ras homolog of the RAS PROTEINS.

ras-Related GTPases [M0328880]

Reagins [M0018546]
Antibodies, especially IGE, that bind to tissue of the same species so that ANTIGENS induce release of HISTAMINE and other vasoactive agents. HYPERSENSITIVITY is the clinical manifestation.

Rec A Recombinases [M0018549]
A family of recombinases initially identified in BACTERIA. They catalyze the ATP-driven exchange of DNA strands in GENETIC RECOMBINATION. The product of the reaction consists of a duplex and a displaced single-stranded loop, which has the shape of the letter D and is therefore called a D-loop structure.

Receptal [M0003075]

Receptor Activator of Nuclear Factor-kappa B [M0371270]
A tumor necrosis factor receptor family member that is specific for RANK LIGAND and plays a role in bone homeostasis by regulating osteoclastogenesis. It also expressed on DENDRITIC CELLS where is plays a role in regulating dendritic cell survival. Signaling by the activated receptor occurs through its association with TNF RECEPTOR-ASSOCIATED FACTORS.

Receptor Protein-Tyrosine Kinases [M0328256]
A class of cellular receptors that have an intrinsic PROTEIN-TYROSINE KINASE activity.

Receptor, Adenosine A1 [M0027232]
A subtype of ADENOSINE RECEPTOR that is found expressed in a variety of tissues including the BRAIN and DORSAL HORN NEURONS. The receptor is generally considered to be coupled to the GI, INHIBITORY G-PROTEIN which causes down regulation of CYCLIC AMP.

Receptor, Adenosine A2A [M0232576]
A subclass of adenosine A2 receptors found in LEUKOCYTES, the SPLEEN, the THYMUS and a variety of other tissues. It is generally considered to be a receptor for ADENOSINE that couples to the GS, STIMULATORY G-PROTEIN.

Receptor, Adenosine A2B [M0283259]
A subclass of adenosine A2 receptors found in the CECUM, the COLON, the BLADDER, and a variety of other tissues. It is generally considered to be a low affinity receptor for ADENOSINE that couples to the GS, STIMULATORY G-PROTEIN.

Receptor, Adenosine A3 [M0279777]
A subtype of ADENOSINE RECEPTOR that is found expressed in a variety of locations including the BRAIN and endocrine tissues. The receptor is generally considered to be coupled to the GI, INHIBITORY G-PROTEIN which causes down regulation of CYCLIC AMP.

Receptor, Anaphylatoxin C5a [M0132707]
A G-protein-coupled receptor that signals an increase in intracellular calcium in response to the potent ANAPHYLATOXIN peptide COMPLEMENT C5A.

Receptor, Angiotensin II [M0018557]

Receptor, Angiotensin III [M0018558]

Receptor, Angiotensin, Type 1 [M0265393]
An angiotensin receptor subtype that is expressed at high levels in a variety of adult tissues including the CARDIOVASCULAR SYSTEM, the KIDNEY, the ENDOCRINE SYSTEM and the NERVOUS SYSTEM. Activation of the type 1 angiotensin receptor causes VASOCONSTRICTION and sodium retention.

Receptor, Angiotensin, Type 1a [M0253657]
A subtype of angiotensin receptor found primarily in rodent species that have two type 1 angiotensin receptor genes.

Receptor, Angiotensin, Type 1b [M0275726]
A subtype of angiotensin receptor found primarily in rodent species that have two type 1 angiotensin receptor genes.

Receptor, Angiotensin, Type 2 [M0261994]
An angiotensin receptor subtype that is expressed at high levels in fetal tissues. Many effects of the angiotensin type 2 receptor such as VASODILATION and sodium loss are the opposite of that of the ANGIOTENSIN TYPE 1 RECEPTOR.

Receptor, Bradykinin B1 [M0255301]
A subtype of bradykinin receptor that is induced in response to INFLAMMATION. It may play a role in chronic inflammation and has a high specificity for KININS lacking the C-terminal ARGININE such as des-Arg(10)-kallidin and des-Arg(9)-bradykinin. The receptor is coupled to G-PROTEIN, GQ-G11 ALPHA FAMILY and G-PROTEIN, GI-GO ALPHA FAMILY signaling proteins.

Receptor, Bradykinin B2 [M0364350]
A constitutively expressed subtype of bradykinin receptor that may play a role in the acute phase of the inflammatory and pain response. It has high specificity for intact forms of BRADYKININ and KALLIDIN. The receptor is coupled to G-PROTEIN, GQ-G11 ALPHA FAMILY and G-PROTEIN, GI-GO ALPHA FAMILY signaling proteins.

Receptor, Cannabinoid, CB1 [M0155202]
A subclass of cannabinoid receptor found primarily on central and peripheral NEURONS where it may play a role modulating NEUROTRANSMITTER release.

Receptor, Cannabinoid, CB2 [M0155203]
A subclass of cannabinoid receptor found primarily on immune cells where it may play a role modulating release of CYTOKINES.

Receptor, Cholecystokinin A [M0226183]
A subtype of cholecystokinin receptor found primarily in the PANCREAS; STOMACH; INTESTINE; and GALLBLADDER. It plays a role in regulating digestive functions such as gallbladder contraction, pancreatic enzyme secretion and absorption in the GASTROINTESTINAL TRACT.

Receptor, Cholecystokinin B [M0223175]
A subtype of cholecystokinin receptor found primarily in the CENTRAL NERVOUS SYSTEM and the GASTRIC MUCOSA. It may play a role as a neuromodulator of dopaminergic neurotransmission the regulation of GASTRIC ACID secretion from GASTRIC PARIETAL CELLS.

Receptor, Ciliary Neurotrophic Factor [M0328260]
Cell surface receptors for CILIARY NEUROTROPHIC FACTOR. They are heterotrimeric proteins formed by the association of the CILIARY NEUROTROPHIC FACTOR RECEPTOR ALPHA SUBUNIT with the LEUKEMIA INHIBITOR FACTOR RECEPTOR ALPHA SUBUNIT and the CYTOKINE RECEPTOR GP130. Although the receptor regulates neuronal development, it is structurally similar to the cytokine receptor for INTERLEUKIN-6; (RECEPTORS, INTERLEUKIN-6).

Receptor, Endothelin A [M0218648]
A subtype of endothelin receptor found predominantly in the VASCULAR SMOOTH MUSCLE. It has a high affinity for ENDOTHELIN-1 and ENDOTHELIN-2.

Receptor, Endothelin B [M0219577]
A subtype of endothelin receptor found predominantly in the KIDNEY. It may play a role in reducing systemic ENDOTHELIN levels.

Receptor, Endothelin B, Type 2 [M0288137]

Receptor, EphA1 [M0333628]
The founding member of the Eph family receptors. It was first cloned from an erythropoietin-producing human hepatocellular carcinoma cell line and is highly conserved among many mammalian species. Overproduction of the EphA1 receptor is associated with tumors and tumor cells of epithelial origin. It is also expressed at high levels in LIVER; LUNG; and KIDNEY; which is in contrast to many other members of the Eph receptor that are found primarily in tissues of the nervous system.

Receptor, EphA2 [M0180256]
An Eph family receptor found abundantly in tissues of epithelial origin. It is expressed in a diverse array of tissues during embryonic development, suggesting that it may play a role in embryogenesis. In adult tissues high levels of the receptor are expressed in the LUNG; SKIN; SMALL INTESTINE and OVARY.

Receptor, EphA3 [M0373345]
An eph family receptor that is found primarily in adult BRAIN and variety of tissues in the developing embryo tissues. During embryonic development high levels of EphA3 receptor expression is seen in the nervous system and coincides with neuronal cell migration, suggesting a role for this protein in axonal pathfinding.

Receptor, EphA4 [M0210608]
An eph family receptor found in variety of tissues including BRAIN. During embryogenesis, EphA4 receptor exhibits a diverse spatial and temporal pattern of expression suggesting its role in multiple developmental processes.

Receptor, EphA5 [M0290346]
An eph family receptor found primarily in differentiated neuronal tissues. Several isoforms of EphA5 receptor occur due to multiple alternative RNA splicing. The protein is prominently expressed in the NEURONS of the LIMBIC SYSTEM during development and throughout adult life, suggesting its role in the plasticity of limbic structure and function.

Receptor, EphA6 [M0384639]
An eph family receptor that is found in a variety of neuronal regions of the BRAIN. In contrast to the other proteins in this class, it is expressed at higher levels in adult tissues than in embryonic tissues.

Receptor, EphA7 [M0286660]
An eph family receptor found widely expressed in embryo tissues, including the NERVOUS SYSTEM. In the BRAIN high levels of EphA7 expression occurs in the anterior tectum, medulla, RHOMBENCEPHALON, and SUBCOMMISSURAL ORGAN. Several isoforms of the protein occur due to multiple alternative spicing of the EphA7 mRNA.

Receptor, EphA8 [M0364981]
An eph family receptor found exclusively in BRAIN. EphA8 receptors may play a role in the axonal guidance of a subset of tectal commissural NEURONS.

Receptor, EphB1 [M0354747]
An eph family receptor found primarily in the nervous system. In the embryonic BRAIN EphB1 receptor expression occurs in the mantle layer and increases with the progression of embryogenesis. In adult brain it is found in the several regions including the CEREBELLUM; CEREBRAL CORTEX; and CAUDATE NUCLEUS; and PUTAMEN.

Receptor, EphB2 [M0197095]
An eph family receptor found widely expressed in embryonic and adult tissues. High levels of EphB2 receptor are observed in growing AXONS and NERVE FIBERS. Several isoforms of the protein exist due to multiple alternative mRNA splicing.

Receptor, EphB3 [M0398428]
An eph family receptor found in a number of tissues including BRAIN; LUNG; KIDNEY; PANCREAS; INTESTINE; and HEART. During embryogenesis EphB3 receptor is expressed at high levels in the brain.

Receptor, EphB4 [M0357457]
An eph family receptor found a variety of adult and embryonic tissues. Unlike the majority of proteins in this class there is little or no expression of EphB4 receptor in the BRAIN. It has been found at high levels in developing mammary glands and in invasive mammary tumors.

Receptor, EphB5 [M0409371]
An eph family receptor found at high levels in adult THYMUS and RETINA. In embryonic tissues it is found in many developing organs.

Receptor, EphB6 [M0402451]
An eph family receptor found primarily in BRAIN and THYMUS. The EphB6 receptor is unusual in that its tyrosine kinase domain shares little homology with other members of this class. The unusual tyrosine kinase domain of this receptor appears to result in its lack of tyrosine kinase activity.

Receptor, Epidermal Growth Factor [M0018582]
A cell surface receptor involved in regulation of cell growth and differentiation. It is specific for EPIDERMAL GROWTH FACTOR and EGF related peptides including TRANSFORMING GROWTH FACTOR ALPHA, amphiregulin, and heparin-binding EGF-like growth factor. The binding of ligand to the receptor causes activation of its intrinsic tyrosine kinase activity and rapid internalization of the receptor-ligand complex into the cell.

Receptor, erbB-2 [M0028048]
A cell surface protein-tyrosine kinase receptor that is found to be overexpressed in a significant number of adenocarcinomas. It has extensive homology to and can heterodimerize with the EGF receptor (RECEPTOR, EPIDERMAL GROWTH FACTOR), the erbB-3 receptor (RECEPTOR, ERBB-3) and the erbB-4 receptor. Activation of the erbB-2 receptor occurs during heterodimer formation with a ligand-bound erbB receptor family members.

Receptor, erbB-3 [M0328262]
A cell surface protein-tyrosine kinase receptor that is specific for NEUREGULINS. It has extensive homology to and can heterodimerize with the EGF Receptor (RECEPTOR, EPIDERMAL GROWTH FACTOR) and the erbB-2 receptor (RECEPTOR, ERBB-2). Overexpression of the erbB-3 receptor is associated with tumorigenesis.

Receptor, Fibroblast Growth Factor, Type 1 [M0204502]
A fibroblast growth factor receptor with specificity for FIBROBLAST GROWTH FACTORS; HEPARAN SULFATE PROTEOGLYCAN; and NEURONAL CELL ADHESION MOLECULES. Several variants of the receptor exist due to multiple ALTERNATIVE SPLICING of its mRNA. Fibroblast growth factor receptor 1 is a tyrosine kinase that transmits signals through the MAP KINASE SIGNALING SYSTEM.

Receptor, Fibroblast Growth Factor, Type 2 [M0189339]
A fibroblast growth factor receptor that is found in two isoforms. One receptor isoform is found in the MESENCHYME and is activated by FIBROBLAST GROWTH FACTOR 2. A second isoform of fibroblast growth factor receptor 2 is found mainly in EPITHELIAL CELLS and is activated by FIBROBLAST GROWTH FACTOR 7 and FIBROBLAST GROWTH FACTOR 10. Mutation of the gene for fibroblast growth factor receptor 2 can result in APERT SYNDROME.

Receptor, Fibroblast Growth Factor, Type 3 [M0197390]
A fibroblast growth factor receptor that regulates CHONDROCYTE growth and CELL DIFFERENTIATION. Mutations in the gene for fibroblast growth factor receptor 3 have been associated with ACHONDROPLASIA; THANATOPHORIC DYSPLASIA and NEOPLASTIC CELL TRANSFORMATION.

Receptor, Fibroblast Growth Factor, Type 4 [M0197156]
A fibroblast growth factor receptor that is mainly expressed in LUNG; KIDNEY; PANCREAS; and SPLEEN. It also plays an important role in SKELETAL MUSCLE development and can contribute to NEOPLASTIC CELL TRANSFORMATION.

Receptor, Fibroblast Growth Factor, Type 5 [M0391371]
The most divergent of the known fibroblast growth factor receptors. It does not contain an intracellular TYROSINE KINASE domain and has been shown to interact with FIBROBLAST GROWTH FACTOR 2. Fibroblast growth factor receptor 5 is found primarily in skeletal tissue.

Receptor, Galanin, Type 1 [M0147579]
The most abundant galanin receptor subtype. It displays a high affinity for the full-length form of GALANIN.

Receptor, Galanin, Type 2 [M0147580]
A galanin receptor subtype with broad specificity for full length GALANIN, galanin peptide fragments and GALANIN-LIKE PEPTIDE.

Receptor, Galanin, Type 3 [M0147577]
A galanin receptor subtype with high affinity for GALANIN-LIKE PEPTIDE and low affinity for full length GALANIN and galanin peptide fragments.

Receptor, IGF Type 1 [M0026587]
A protein-tyrosine kinase receptor that is closely related in structure to the INSULIN RECEPTOR. Although commonly referred to as the IGF-I receptor, it binds both IGF-I and IGF-II with high affinity. It is comprised of a tetramer of two alpha and two beta subunits which are derived from cleavage of a single precusor protein. The beta subunit contains an intrinsic tyrosine kinase domain.

Receptor, IGF Type 1 alpha Subunit [M0332233]

Receptor, IGF Type 1 beta Subunit [M0332241]

Receptor, IGF Type 2 [M0026588]
A receptor that is specific for IGF-II and mannose-6-phosphate. The receptor is a 250-kDa single chain polypeptide which is unrelated in structure to the type 1 IGF receptor (RECEPTOR, IGF TYPE 1) and does not have a tyrosine kinase domain.

Receptor, Insulin [M0018605]
A cell surface receptor for INSULIN. It is comprised of a tetramer of two alpha and two beta subunits which are derived from cleavage of a single precusor protein. The receptor contains an intrinsic tyrosine kinase domain that is located within the beta subunit. Activation of the receptor by INSULIN results in numerous metabolic changes including increased uptake of GLUCOSE into the LIVER; MUSCLE; and ADIPOSE TISSUE.

Receptor, Interferon alpha-beta [M0231011]
A ubiquitously expressed heterodimeric receptor that is specific for both INTERFERON-ALPHA and INTERFERON-BETA. It is composed of two subunits referred to as IFNAR1 and IFNAR2. The IFNAR2 subunit is believed to serve as the ligand-binding chain; however both chains are required for signal transduction. The interferon alpha-beta receptor signals through the action of JANUS KINASES such as the TYK2 KINASE.

Receptor, Macrophage Colony-Stimulating Factor [M0024703]
A receptor for MACROPHAGE COLONY-STIMULATING FACTOR encoded by the c-fms proto-oncogene (GENES, FMS). It contains an intrinsic protein-tyrosine kinase activity. When activated the receptor undergoes autophosphorylation, phosphorylation of down-stream signaling molecules and rapid down-regulation.

Receptor, Melanocortin, Type 1 [M0230664]
A melanocortin receptor subtype found primarily in MELANOCYTES. It shows specificity for ALPHA-MSH and ADRENOCORTICOTROPIC HORMONE. Loss of function mutations of the type 1 melanocortin receptor account for the majority of red hair and fair skin recessive traits in human.

Receptor, Melanocortin, Type 2 [M0221241]
A melanocortin receptor subtype found primarily in the ADRENAL CORTEX. It shows specificity for ADRENOCORTICOTROPIC HORMONE.

Receptor, Melanocortin, Type 3 [M0226052]
A melanocortin receptor subtype found primarily in BRAIN. It shows specificity for ALPHA-MSH; BETA-MSH; GAMMA-MSH and ADRENOCORTICOTROPIC HORMONE.

Receptor, Melanocortin, Type 4 [M0218909]
A melanocortin receptor subtype found primarily in BRAIN. It shows specificity for ALPHA-MSH; BETA-MSH and ADRENOCORTICOTROPIC HORMONE.

Receptor, Melatonin, 1C [M0096686]
A melatonin receptor subtype found in non-mammalian species.

Receptor, Melatonin, MT1 [M0429989]
A melatonin receptor subtype that is primarily found in the HYPOTHALAMUS and in the KIDNEY.

Receptor, Melatonin, MT2 [M0429990]
A melatonin receptor subtype primarily found expressed in the BRAIN and RETINA.

Receptor, Melatonin, MT3 [M0444405]
A subtype of melatonin receptor that has lower affinity for MELATONIN than the MT1 and MT2 subtypes.

Receptor, Muscarinic M1 [M0268220]
A specific subtype of muscarinic receptor that has a high affinity for the drug PIRENZEPINE. It is found in the peripheral GANGLIA where it signals a variety of physiological functions such as GASTRIC ACID secretion and BRONCHOCONSTRICTION. This subtype of muscarinic receptor is also found in neuronal tissues including the CEREBRAL CORTEX and HIPPOCAMPUS where it mediates the process of MEMORY and LEARNING.

Receptor, Muscarinic M2 [M0255463]
A specific subtype of muscarinic receptor found in the lower BRAIN, the HEART and in SMOOTH MUSCLE-containing organs. Although present in smooth muscle the M2 muscarinic receptor appears not to be involved in contractile responses.

Receptor, Muscarinic M3 [M0237773]
A subclass of muscarinic receptor that mediates cholinergic-induced contraction in a variety of SMOOTH MUSCLES.

Receptor, Muscarinic M4 [M0263510]
A specific subtype of muscarinic receptor found in the CORPUS STRIATUM and the LUNG. It has similar receptor binding specificities to MUSCARINIC RECEPTOR M1 and MUSCARINIC RECEPTOR M2.

Receptor, Muscarinic M5 [M0450748]
A specific subtype of muscarinic receptor found in a variety of locations including the SALIVARY GLANDS and the SUBSTANTIA NIGRA and VENTRAL TEGMENTAL AREA of the BRAIN.

Receptor, Nerve Growth Factor [M0328264]
A low affinity receptor that binds NERVE GROWTH FACTOR; BRAIN-DERIVED NEUROTROPHIC FACTOR; NEUROTROPHIN 3; and neurotrophin 4.

Receptor, Notch1 [M0192109]
A notch receptor that interacts with a variety of ligands and regulates SIGNAL TRANSDUCTION PATHWAYS for multiple cellular processes. It is widely expressed during EMBRYOGENESIS and is essential for EMBRYONIC DEVELOPMENT.

Receptor, Notch2 [M0244873]
A notch receptor that plays an important role in CELL DIFFERENTIATION in a variety of cell types. It is the preferentially expressed notch receptor in mature B-LYMPHOCYTES.

Receptor, PAR-1 [M0283418]
A thrombin receptor subtype that couples to HETEROTRIMERIC GTP-BINDING PROTEINS resulting in the activation of a variety of signaling mechanisms including decreased intracellular CYCLIC AMP, increased PHOSPHOLIPASE C and increased PHOSPHOLIPASE A2.

Receptor, PAR-2 [M0236839]
A G-protein-coupled, proteinase-activated receptor that is expressed in a variety of tissues including ENDOTHELIUM; LEUKOCYTES; and the GASTROINTESTINAL TRACT. The receptor is activated by TRYPSIN, which cleaves off the N-terminal peptide from the receptor. The new N-terminal peptide is a cryptic ligand for the receptor. The uncleaved receptor can also be activated by the N-terminal peptide present on the activated THROMBIN RECEPTOR and by small synthetic peptides that contain the unmasked N-terminal sequence.

Receptor, Parathyroid Hormone, Type 1 [M0444517]
A parathyroid hormone receptor subtype that recognizes both PARATHYROID HORMONE and PARATHYROID HORMONE-RELATED PROTEIN. It is a G-protein-coupled receptor that is expressed at high levels in BONE and in KIDNEY.

Receptor, Parathyroid Hormone, Type 2 [M0265116]
A parathyroid hormone receptor subtype found in the BRAIN and the PANCREAS. It is a G-protein-coupled receptor with a ligand specificity that varies between homologs from different species.

Receptor, Platelet-Derived Growth Factor alpha [M0328265]
A PDGF receptor that binds specifically to both PDGF-A chains and PDGF-B chains. It contains a protein-tyrosine kinase activity that is involved in SIGNAL TRANSDUCTION.

Receptor, Platelet-Derived Growth Factor beta [M0328267]
A PDGF receptor that binds specifically to the PDGF-B chain. It contains a protein-tyrosine kinase activity that is involved in SIGNAL TRANSDUCTION.

Receptor, Serotonin, 5-HT1A [M0215658]
A serotonin receptor subtype found distributed through the CENTRAL NERVOUS SYSTEM where they are involved in neuroendocrine regulation of ACTH secretion. The fact that this serotonin receptor subtype is particularly sensitive to SEROTONIN AGONISTS such as BUSPIRONE suggests its role in the modulation of ANXIETY and DEPRESSION.

Receptor, Serotonin, 5-HT1B [M0223056]
A serotonin receptor subtype found at high levels in the BASAL GANGLIA and the frontal cortex. It plays a role as a terminal autoreceptor that regulates the rate of SEROTONIN release from nerve endings. This serotonin receptor subtype is closely related to and has similar drug binding properties as the 5-HT1D RECEPTOR. It is particularly sensitive to the agonist SUMATRIPTAN and may be involved in mediating the drug's antimigraine effect.

Receptor, Serotonin, 5-HT1D [M0267233]
A serotonin receptor subtype that is localized to the CAUDATE NUCLEUS; PUTAMEN; the NUCLEUS ACCUMBENS; the HIPPOCAMPUS, and the RAPHE NUCLEI. It plays a role as a terminal autoreceptor that regulates the rate of SEROTONIN release from nerve endings. This serotonin receptor subtype is closely related to and has similar drug binding properties as the 5-HT1B RECEPTOR, but is expressed at low levels. It is particularly sensitive to the agonist SUMATRIPTAN and may be involved in mediating the drug's antimigrane effect.

Receptor, Serotonin, 5-HT2A [M0237044]
A serotonin receptor subtype found widely distributed in peripheral tissues where it mediates the contractile responses of variety of tissues that contain SMOOTH MUSCLE. Selective 5-HT2A receptor antagonists include KETANSERIN. The 5-HT2A subtype is also located in BASAL GANGLIA and CEREBRAL CORTEX of the BRAIN where it mediates the effects of HALLUCINOGENS such as LSD.

Receptor, Serotonin, 5-HT2B [M0235961]
A serotonin receptor subtype found in the BRAIN; HEART; LUNGS; PLACENTA and DIGESTIVE SYSTEM organs. A number of functions have been attributed to the action of the 5-HT2B receptor including the development of cardiac myocytes (MYOCYTES, CARDIAC) and the contraction of SMOOTH MUSCLE.

Receptor, Serotonin, 5-HT2C [M0239497]
A serotonin receptor subtype found primarily in the CENTRAL NERVOUS SYSTEM and the CHOROID PLEXUS. This receptor subtype is believed to mediate the anorectic action of SEROTONIN, while selective antagonists of the 5-HT2C receptor appear to induce ANXIETY. Several isoforms of this receptor subtype exist, due to adenine deaminase editing of the receptor mRNA.

Receptor, Serotonin, 5-HT3A [M0244238]

Receptor, Serotonin, 5-HT3B [M0358297]

Receptor, TIE-1 [M0442055]
A TIE receptor found predominantly on ENDOTHELIAL CELLS. It is considered essential for vascular development and can form a heterodimer with the TIE-2 RECEPTOR. The TIE-1 receptor may play a role in regulating BLOOD VESSEL stability and maturation.

Receptor, TIE-2 [M0217220]
A TIE receptor tyrosine kinase that is found almost exclusively on ENDOTHELIAL CELLS. It is required for both normal embryonic vascular development (NEOVASCULARIZATION, PHYSIOLOGIC) and tumor angiogenesis (NEOVASCULARIZATION, PATHOLOGIC).

Receptor, trkA [M0328268]
A protein-tyrosine kinase receptor that is specific for NERVE GROWTH FACTOR; NEUROTROPHIN 3; neurotrophin 4, neurotrophin 5. It plays a crucial role in pain sensation and thermoregulation in humans. Gene mutations that cause loss of receptor function are associated with congenital insensitivity to pain with anhidrosis, while gene rearrangements that activate the protein-tyrosine kinase function are associated with tumorigenesis.

Receptor, trkB [M0328269]
A protein-tyrosine kinase receptor that is specific for BRAIN-DERIVED NEUROTROPHIC FACTOR; NEUROTROPHIN 3; neurotrophin 4 and neurotrophin 5. It is widely expressed in nervous tissue and plays a role in mediating the effects of neurotrophins on growth and differentiation of neuronal cells.

Receptor, trkC [M0328272]
A protein-tyrosine kinase receptor that is specific for NEUROTROPHIN 3. It is widely expressed in nervous tissue and may play a role in mediating the effects of NEUROTROPHIN 3 on the proliferation and differentiation of NEURONS.

Receptor-CD3 Complex, Antigen, T-Cell [M0026196]
Molecule composed of the non-covalent association of the T-cell antigen receptor (RECEPTORS, ANTIGEN, T-CELL) with the CD3 complex (ANTIGENS, CD3). This association is required for the surface expression and function of both components. The molecule consists of up to seven chains: either the alpha/beta or gamma/delta chains of the T-cell receptor, and four or five chains in the CD3 complex.

Receptor-Interacting Protein Serine-Threonine Kinase 1 [M0492996]

Receptor-Interacting Protein Serine-Threonine Kinase 2 [M0290667]
A RIP serine-theonine kinase that contains a C-terminal caspase activation and recruitment domain. It can signal by associating with other CARD-signaling adaptor proteins and INITIATOR CASPASES that contain CARD domains within their N-terminal pro-domain region.

Receptor-Interacting Protein Serine-Threonine Kinase 3 [M0493000]

Receptor-Interacting Protein Serine-Threonine Kinases [M0492994]
A family of serine-threonine kinases that plays a role in intracellular signal transduction by interacting with a variety of signaling adaptor proteins such as CRADD SIGNALING ADAPTOR PROTEIN; TNF RECEPTOR-ASSOCIATED FACTOR 2; and TNF RECEPTOR-ASSOCIATED DEATH DOMAIN PROTEIN. Although they were initially described as death domain-binding adaptor proteins, members of this family may contain other protein-binding domains such as those involving caspase activation and recruitment.

Receptors, Adenosine A2 [M0027233]
A subclass of ADENOSINE RECEPTORS that are generally considered to be coupled to the GS, STIMULATORY G-PROTEIN which causes up regulation of CYCLIC AMP.

Receptors, ADP [M0027235]

Receptors, Adrenergic [M0018552]
Cell-surface proteins that bind epinephrine and/or norepinephrine with high affinity and trigger intracellular changes. The two major classes of adrenergic receptors, alpha and beta, were originally discriminated based on their cellular actions but now are distinguished by their relative affinity for characteristic synthetic ligands. Adrenergic receptors may also be classified according to the subtypes of G-proteins with which they bind; this scheme does not respect the alpha-beta distinction.

Receptors, Adrenergic, alpha [M0018554]
One of the two major pharmacological subdivisions of adrenergic receptors. The alpha-beta distinction was originally based on cellular effects of receptor activation but now relies on the relative affinities for certain synthetic ligands. alpha-Adrenergic receptors are further subdivided into several subclasses based on studies of endogenous and cloned receptors.

Receptors, Adrenergic, alpha-1 [M0027574]
A subclass of alpha-adrenergic receptors (RECEPTORS, ADRENERGIC, ALPHA). alpha-1 Adrenergic receptors can be pharmacologically discriminated, e.g., by their high affinity for the agonist phenylephrine and the antagonist prazosin. They are widespread, with clinically important concentrations in the liver, the heart, vascular, intestinal, and genitourinary smooth muscle, and the central and peripheral nervous systems.

Receptors, Adrenergic, alpha-2 [M0027575]
A subclass of alpha-adrenergic receptors (RECEPTORS, ADRENERGIC, ALPHA). alpha-2 Adrenergic receptors can be pharmacologically discriminated, e.g., by their high affinity for the agonist clonidine and the antagonist yohimbine. They are found on pancreatic beta cells, platelets, and vascular smooth muscle, as well as both pre- and postsynaptically in the central and peripheral nervous systems.

Receptors, Adrenergic, beta [M0018555]
One of the two major pharmacologically defined classes of adrenergic receptors. The alpha-beta distinction was originally based on the cellular effects of receptor activation but now relies on the relative affinities for characteristic synthetic ligands. Beta adrenergic receptors are further subdivided based on information from endogenous and cloned receptors.

Receptors, Adrenergic, beta-1 [M0027576]
A subclass of beta-adrenergic receptors (RECEPTORS, ADRENERGIC, BETA). beta-1 Adrenergic receptors are equally sensitive to epinephrine and norepinephrine and bind the agonist dobutamine and the antagonist metoprolol with high affinity. They are found in the heart, juxtaglomerular cells, and in the central and peripheral nervous systems.

Receptors, Adrenergic, beta-2 [M0027577]
A subclass of beta-adrenergic receptors (RECEPTORS, ADRENERGIC, BETA). beta-2 Adrenergic receptors are more sensitive to epinephrine than to norepinephrine and have a high affinity for the agonist terbutaline. They are widespread, with clinically important roles in skeletal muscle, liver, and vascular, bronchial, gastrointestinal, and genitourinary smooth muscle.

Receptors, Adrenergic, beta-3 [M0223759]
A subclass of beta-adrenergic receptors (RECEPTORS, ADRENERGIC, BETA). beta-3 Adrenergic receptors are the predominant beta-adrenergic receptor type expressed in white and brown ADIPOCYTES and are involved in modulating ENERGY METABOLISM and THERMOGENESIS.

Receptors, Albumin [M0026493]
Cell surface proteins that bind albumin with high affinity and trigger intracellular changes influencing the behavior of cells.

Receptors, Aldosterone [M0026494]
Cytoplasmic proteins that specifically bind aldosterone and mediate its cellular effects. The aldosterone-bound receptor acts in the nucleus to regulate the transcription of specific segments of DNA.

Receptors, Amino Acid [M0026495]
Cell surface proteins that bind amino acids and trigger changes which influence the behavior of cells. Glutamate receptors are the most common receptors for fast excitatory synaptic transmission in the vertebrate central nervous system, and GAMMA-AMINOBUTYRIC ACID and glycine receptors are the most common receptors for fast inhibition.

Receptors, AMPA [M0027286]
Cell surface proteins that bind glutamate and directly gate ion channels in cell membranes. AMPA receptors were originally discriminated from other glutamate receptors by their affinity for the agonist AMPA (alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid). They are probably the most common mediators of fast excitatory synaptic transmission in the central nervous system. Several subtypes have been cloned, and for some types the traditional distinction from kainate receptors may not apply.

Receptors, Androgen [M0018556]
Proteins, generally found in the cytoplasm, that specifically bind androgens and mediate their cellular actions. The complex of the androgen and receptor migrates to the nucleus where it induces transcription of specific segments of DNA.

Receptors, Angiotensin [M0018559]
Cell surface proteins that bind ANGIOTENSINS and trigger intracellular changes influencing the behavior of cells.

Receptors, Antigen [M0018561]
Molecules on the surface of B- and T-lymphocytes that recognize and combine with specific antigens.

Receptors, Antigen, B-Cell [M0018562]
IMMUNOGLOBULINS on the surface of B-LYMPHOCYTES. Their MESSENGER RNA contains an EXON with a membrane spanning sequence, producing immunoglobulins in the form of type I transmembrane proteins as opposed to secreted immunoglobulins (ANTIBODIES) which do not contain the membrane spanning segment.

Receptors, Antigen, T-Cell [M0018563]
Molecules on the surface of T-lymphocytes that recognize and combine with antigens. The receptors are non-covalently associated with a complex of several polypeptides collectively called CD3 antigens (ANTIGENS, CD3). Recognition of foreign antigen and the major histocompatibility complex is accomplished by a single heterodimeric antigen-receptor structure, composed of either alpha-beta (RECEPTORS, ANTIGEN, T-CELL, ALPHA-BETA) or gamma-delta (RECEPTORS, ANTIGEN, T-CELL, GAMMA-DELTA) chains.

Receptors, Antigen, T-Cell, alpha-beta [M0025428]
T-cell receptors composed of CD3-associated alpha and beta polypeptide chains and expressed primarily in CD4+ or CD8+ T-cells. Unlike immunoglobulins, the alpha-beta T-cell receptors recognize antigens only when presented in association with major histocompatibility (MHC) molecules.

Receptors, Antigen, T-Cell, gamma-delta [M0025425]
T-cell receptors composed of CD3-associated gamma and delta polypeptide chains and expressed primarily in CD4-/CD8- T-cells. The receptors appear to be preferentially located in epithelial sites and probably play a role in the recognition of bacterial antigens. The T-cell receptor gamma/delta chains are separate and not related to the gamma and delta chains which are subunits of CD3 (see ANTIGENS, CD3).

Receptors, Aryl Hydrocarbon [M0027573]
Cytoplasmic proteins that bind certain aryl hydrocarbons, translocate to the nucleus, and activate transcription of particular DNA segments. AH receptors are identified by their high-affinity binding to several carcinogenic or teratogenic environmental chemicals including polycyclic aromatic hydrocarbons found in cigarette smoke and smog, heterocyclic amines found in cooked foods, and halogenated hydrocarbons including dioxins and polychlorinated biphenyls. No endogenous ligand has been identified, but an unknown natural messenger with a role in cell differentiation and development is suspected.

Receptors, ATP [M0027236]

Receptors, Atrial Natriuretic Factor [M0026496]
Cell surface proteins that bind ATRIAL NATRIURETIC FACTOR with high affinity and trigger intracellular changes influencing the behavior of cells. They contain intrinsic guanylyl cyclase activity.

Receptors, Biogenic Amine [M0027156]
Cell surface proteins that bind biogenic amines with high affinity and regulate intracellular signals which influence the behavior of cells. Biogenic amine is a chemically imprecise term which, by convention, includes the catecholamines epinephrine, norepinephrine, and dopamine, the indoleamine serotonin, the imidazolamine histamine, and compounds closely related to each of these.

Receptors, Bombesin [M0027187]
Cell surface proteins that bind bombesin or closely related peptides with high affinity and trigger intracellular changes influencing the behavior of cells. Gastrin- releasing peptide (GRP); GRP 18-27 (neuromedin C), and neuromedin B are endogenous ligands of bombesin receptors in mammals.

Receptors, Bradykinin [M0027185]
Cell surface receptors that bind BRADYKININ and related KININS with high affinity and trigger intracellular changes which influence the behavior of cells. The identified receptor types (B-1 and B-2, or BK-1 and BK-2) recognize endogenous KALLIDIN; t-kinins; and certain bradykinin fragments as well as bradykinin itself.

Receptors, C-Type Lectin [M0422269]

Receptors, Caerulein [M0443806]

Receptors, Calcitonin [M0027186]
Cell surface proteins that bind calcitonin and trigger intracellular changes which influence the behavior of cells. Calcitonin receptors outside the nervous system mediate the role of calcitonin in calcium homeostasis. The role of calcitonin receptors in the brain is not well understood.

Receptors, Calcitonin Gene-Related Peptide [M0027196]
Cell surface proteins that bind calcitonin gene-related peptide (CGRP) with high affinity and trigger intracellular changes which influence the behavior of cells. CGRP receptors are present in both the central nervous system and the periphery and are not the same as calcitonin receptors.

Receptors, Calcitriol [M0027388]
Proteins, usually found in the cytoplasm, that specifically bind calcitriol, migrate to the nucleus, and regulate transcription of specific segments of DNA with the participation of D receptor interacting proteins (called DRIP). Vitamin D is converted in the liver and kidney to calcitriol and ultimately acts through these receptors.

Receptors, Calcium-Sensing [M0225065]
A class of G-protein-coupled receptors that react to varying extracellular CALCIUM levels. Calcium-sensing receptors in the PARATHYROID GLANDS play an important role in the maintenance of calcium HOMEOSTASIS by regulating the release of PARATHYROID HORMONE. They differ from INTRACELLULAR CALCIUM-SENSING PROTEINS which sense intracellular calcium levels.

Receptors, Cannabinoid [M0155215]
A class of G-protein-coupled receptors that are specific for CANNABINOIDS such as those derived from CANNABIS. They also bind a structurally distinct class of endogenous factors referred to as ENDOCANNABINOIDS. The receptor class may play a role in modulating the release of signaling molecules such as NEUROTRANSMITTERS and CYTOKINES.

Receptors, Catecholamine [M0027157]
Cell surface proteins that bind catecholamines with high affinity and trigger intracellular changes which influence the behavior of cells. The catecholamine messengers epinephrine, norepinephrine, and dopamine are synthesized from tyrosine by a common biosynthetic pathway.

Receptors, CCR5 [M0029268]
Seven-transmembrane G protein-coupled receptors for beta-chemokines. They also function as fusion cofactors for macrophage-tropic HIV-1 strains.

Receptors, Cell Surface [M0018574]
Cell surface proteins that bind signalling molecules external to the cell with high affinity and convert this extracellular event into one or more intracellular signals that alter the behavior of the target cell (From Alberts, Molecular Biology of the Cell, 2nd ed, pp693-5). Cell surface receptors, unlike enzymes, do not chemically alter their ligands.

Receptors, Chemokine [M0029262]
Cell surface glycoproteins that bind to chemokines and thus mediate the migration of pro-inflammatory molecules. The receptors are members of the seven-transmembrane G protein-coupled receptor family. Like the CHEMOKINES themselves, the receptors can be divided into at least three structural branches: CR, CCR, and CXCR, according to variations in a shared cysteine motif.

Receptors, Cholecystokinin [M0018564]
Cell surface proteins that bind cholecystokinin (CCK) with high affinity and trigger intracellular changes influencing the behavior of cells. Cholecystokinin receptors are activated by GASTRIN as well as by CCK-4; CCK-8; and CCK-33. Activation of these receptors evokes secretion of AMYLASE by pancreatic acinar cells, acid and PEPSIN by stomach mucosal cells, and contraction of the PYLORUS and GALLBLADDER. The role of the widespread CCK receptors in the central nervous system is not well understood.

Receptors, Cholinergic [M0018566]
Cell surface proteins that bind acetylcholine with high affinity and trigger intracellular changes influencing the behavior of cells. Cholinergic receptors are divided into two major classes, muscarinic and nicotinic, based originally on their affinity for nicotine and muscarine. Each group is further subdivided based on pharmacology, location, mode of action, and/or molecular biology.

Receptors, Collagen [M0111799]
Collagen receptors are cell surface receptors that modulate signal transduction between cells and the EXTRACELLULAR MATRIX. They are found in many cell types and are involved in the maintenance and regulation of cell shape and behavior, including PLATELET ACTIVATION and aggregation, through many different signaling pathways and differences in their affinities for collagen isoforms. Collagen receptors include discoidin domain receptors, INTEGRINS, and glycoprotein VI.

Receptors, Colony-Stimulating Factor [M0024701]
Cell surface receptors for colony stimulating factors, local mediators, and hormones that regulate the survival, proliferation, and differentiation of hemopoietic cells.

Receptors, Complement [M0018568]
Molecules on the surface of some B-lymphocytes and macrophages, that recognize and combine with the C3b, C3d, C1q, and C4b components of complement.

Receptors, Complement 3b [M0026497]
Molecular sites on or in some B-lymphocytes and macrophages that recognize and combine with COMPLEMENT C3B. The primary structure of these receptors reveal that they contain transmembrane and cytoplasmic domains, with their extracellular portion composed entirely of thirty short consensus repeats each having 60 to 70 amino acids.

Receptors, Complement 3d [M0026498]
Molecular sites on or in B-lymphocytes, follicular dendritic cells, lymphoid cells, and epithelial cells that recognize and combine with COMPLEMENT C3D. Human complement receptor 2 (CR2) serves as a receptor for both C3dg and the gp350/220 glycoprotein of HERPESVIRUS 4, HUMAN, and binds the monoclonal antibody OKB7, which blocks binding of both ligands to the receptor.

Receptors, Concanavalin A [M0018569]
Glycoprotein moieties on the surfaces of cell membranes that bind concanavalin A selectively; the number and location of the sites depends on the type and condition of the cell.

Receptors, Corticoid Type I [M0027374]

Receptors, Corticoid Type II [M0018593]

Receptors, Corticosteroid [M0018625]

Receptors, Corticotropin [M0027229]
Cell surface receptors that bind CORTICOTROPIN; (ACTH, adrenocorticotropic hormone) with high affinity and trigger intracellular changes. Pharmacology suggests there may be multiple ACTH receptors. An ACTH receptor has been cloned and belongs to a subfamily of G-protein-coupled receptors. In addition to the adrenal cortex, ACTH receptors are found in the brain and immune systems.

Receptors, Corticotropin-Releasing Hormone [M0027206]
Cell surface proteins that bind corticotropin-releasing hormone with high affinity and trigger intracellular changes which influence the behavior of cells. The corticotropin releasing-hormone receptors on anterior pituitary cells mediate the stimulation of corticotropin release by hypothalamic corticotropin releasing factor. The physiological consequence of activating corticotropin-releasing hormone receptors on central neurons is not well understood.

Receptors, CXCR4 [M0029275]
Seven-transmembrane G protein-coupled receptors for alpha-chemokines. They also function as fusion cofactors for T-cell-tropic HIV-1 strains.

Receptors, Cyclic AMP [M0018570]
Cell surface proteins that bind cyclic AMP with high affinity and trigger intracellular changes which influence the behavior of cells. The best characterized cyclic AMP receptors are those of the slime mold Dictyostelium discoideum. The transcription regulator CYCLIC AMP RECEPTOR PROTEIN of prokaryotes is not included nor are the eukaryotic cytoplasmic cyclic AMP receptor proteins which are the regulatory subunits of CYCLIC AMP-DEPENDENT PROTEIN KINASES.

Receptors, Cytoadhesin [M0024500]
A group of INTEGRINS that includes the platelet outer membrane glycoprotein GPIIb-IIIa (PLATELET GLYCOPROTEIN GPIIB-IIIA COMPLEX) and the vitronectin receptor (RECEPTORS, VITRONECTIN). They play a major role in cell adhesion and serve as receptors for fibronectin, von Willebrand factor, and vitronectin.

Receptors, Cytokine [M0027326]
Cell surface proteins that bind cytokines and trigger intracellular changes influencing the behavior of cells.

Receptors, Cytoplasmic [M0027371]

Receptors, Cytoplasmic and Nuclear [M0027373]
Proteins in the cytoplasm or nucleus that specifically bind signaling molecules and trigger changes which influence the behavior of cells. The major groups are the steroid hormone receptors (RECEPTORS, STEROID), which usually are found in the cytoplasm, and the thyroid hormone receptors (RECEPTORS, THYROID HORMONE), which usually are found in the nucleus. Receptors, unlike enzymes, generally do not catalyze chemical changes in their ligands.

Receptors, Death Domain [M0492026]
A family of cell surface receptors that signal via a conserved domain that extends into the cell CYTOPLASM. The conserved domain is referred to as a death domain due to the fact that many of these receptors are involved in signaling APOPTOSIS. Several DEATH DOMAIN RECEPTOR SIGNALING ADAPTOR PROTEINS can bind to the death domains of the activated receptors and through a complex series of interactions activate apoptotic mediators such as CASPASES.

Receptors, Dihydropyridine [M0333104]

Receptors, Diiodotyrosine [M0018627]

Receptors, Dopamine [M0018571]
Cell-surface proteins that bind dopamine with high affinity and trigger intracellular changes influencing the behavior of cells.

Receptors, Dopamine D1 [M0026472]
A subfamily of G-PROTEIN-COUPLED RECEPTORS that bind the neurotransmitter DOPAMINE and modulate its effects. D1-class receptor genes lack INTRONS, and the receptors stimulate ADENYLATE CYCLASE.

Receptors, Dopamine D2 [M0026473]
A subfamily of G-PROTEIN-COUPLED RECEPTORS that bind the neurotransmitter DOPAMINE and modulate its effects. D2-class receptor genes contain INTRONS, and the receptors inhibit ADENYLATE CYCLASE.

Receptors, Dopamine D3 [M0150974]
A subtype of dopamine D2 receptors that are highly expressed in the LIMBIC SYSTEM of the brain.

Receptors, Dopamine D4 [M0187176]
A subtype of dopamine D2 receptors that has high affinity for the antipsychotic CLOZAPINE.

Receptors, Dopamine D5 [M0187180]
A subtype of dopamine D1 receptors that has higher affinity for DOPAMINE and differentially couples to GTP-BINDING PROTEINS.

Receptors, Drug [M0018572]
Proteins that bind specific drugs with high affinity and trigger intracellular changes influencing the behavior of cells. Drug receptors are generally thought to be receptors for some endogenous substance not otherwise specified.

Receptors, Ectodysplasin [M0492654]
Members of the TNF receptor family that are specific for ECTODYSPLASIN. At least two subtypes of the ectodysplasin receptor exist, each being specific for a ectodysplasin isoform. Signaling through ectodysplasin receptors plays an essential role in the normal ectodermal development. Genetic defects that result in loss of ectodysplasin receptor function results ECTODERMAL DYSPLASIA.

Receptors, Eicosanoid [M0027245]
Cell surface proteins that bind eicosanoids with high affinity and trigger intracellular changes influencing the behavior of cells. Among the eicosanoid receptors are receptors for the prostaglandins, thromboxanes, and leukotrienes.

Receptors, Endorphin [M0018580]

Receptors, Endothelin [M0026500]
Cell surface proteins that bind ENDOTHELINS with high affinity and trigger intracellular changes which influence the behavior of cells.

Receptors, Eph Family [M0333630]
A large family of receptor protein-tyrosine kinases that are structurally-related. The name of this family of proteins derives from original protein Eph (now called the EPHA1 RECEPTOR), which was named after the cell line it was first discovered in: Erythropoietin-Producing human Hepatocellular carcinoma cell line. Members of this family have been implicated in regulation of cell-cell interactions involved in nervous system patterning and development.

Receptors, Epoprostenol [M0100420]
Cell surface receptors for EPOPROSTENOL. They are coupled to HETEROTRIMERIC G-PROTEINS.

Receptors, Erythropoietin [M0026501]
Cell surface proteins that bind erythropoietin with high affinity and trigger intracellular changes influencing the behavior of cells.

Receptors, Estradiol [M0018583]
Cytoplasmic proteins that bind estradiol, migrate to the nucleus, and regulate DNA transcription.

Receptors, Estrogen [M0018586]
Cytoplasmic proteins that bind estrogens and migrate to the nucleus where they regulate DNA transcription. Evaluation of the state of estrogen receptors in breast cancer patients has become clinically important.

Receptors, Estrogen, Type I [M0018584]

Receptors, Estrogen, Type II [M0018585]

Receptors, Fc [M0018588]
Molecules found on the surface of some, but not all, B-lymphocytes, T-lymphocytes, and macrophages, which recognize and combine with the Fc (crystallizable) portion of immunoglobulin molecules.

Receptors, Fibrinogen [M0418924]
Receptors that bind FIBRINOGEN through distinct adhesive sequences on the fibrinogen molecule. Although MACROPHAGE-1 ANTIGEN is considered an important signaling molecule for fibrinogen interaction, a variety of INTEGRINS from all three major families, (beta1, beta2, and beta3) have been shown to bind fibrinogen.

Receptors, Fibroblast Growth Factor [M0026502]
Specific molecular sites or structures on cell membranes that react with FIBROBLAST GROWTH FACTORS (both the basic and acidic forms), their analogs, or their antagonists to elicit or to inhibit the specific response of the cell to these factors. These receptors frequently possess tyrosine kinase activity.

Receptors, Fibronectin [M0026503]
Specific cell surface receptors which bind to FIBRONECTINS. Studies have shown that these receptors function in certain types of adhesive contact as well as playing a major role in matrix assembly. These receptors include the traditional fibronectin receptor, also called INTEGRIN ALPHA5BETA1 and several other integrins.

Receptors, Formyl Peptide [M0086185]
A family of G-protein-coupled receptors that was originally identified by its ability to bind N-formyl peptides such as N-FORMYLMETHIONINE LEUCYL-PHENYLALANINE. Since N-formyl peptides are found in MITOCHONDRIA and BACTERIA, this class of receptors is believed to play a role in mediating cellular responses to cellular damage and bacterial invasion. However, non-formylated peptide ligands have also been found for this receptor class.

Receptors, FSH [M0018589]
Cell surface proteins that bind FOLLICLE STIMULATING HORMONE with high affinity and trigger intracellular changes influencing the behavior of cells.

Receptors, G-Protein-Coupled [M0443139]
The largest family of cell surface receptors involved in SIGNAL TRANSDUCTION. They share a common structure and signal through HETEROTRIMERIC G-PROTEINS.

Receptors, GABA [M0027273]
Cell-surface proteins that bind GAMMA-AMINOBUTYRIC ACID with high affinity and trigger changes that influence the behavior of cells. GABA-A receptors control chloride channels formed by the receptor complex itself. They are blocked by bicuculline and usually have modulatory sites sensitive to benzodiazepines and barbiturates. GABA-B receptors act through G-proteins on several effector systems, are insensitive to bicuculline, and have a high affinity for L-baclofen.

Receptors, GABA-A [M0018590]
Cell surface proteins which bind GAMMA-AMINOBUTYRIC ACID and control an integral membrane chloride channel. GABA-A receptors are the most prevalent inhibitory neurotransmitter receptors in the brain. Several isoforms have been cloned, and they belong to a superfamily which includes nicotinic receptors, glycine receptors, and 5HT-3 receptors. Most GABA-A receptors have separate modulatory sites sensitive to benzodiazepines and to barbiturates.

Receptors, GABA-B [M0027274]
Cell surface proteins which bind GAMMA-AMINOBUTYRIC ACID and influence cells via interactions with G-proteins. GABA-B receptors are pharmacologically characterized by their insensitivity to the blocker bicuculline and sensitivity to the agonist L-baclofen. They are found both presynaptically and postsynaptically, and act variously by inhibition of adenylate cyclase, activation of phospholipase A2, activation of potassium channels, and inactivation of voltage-activated calcium channels.

Receptors, Galanin [M0147582]
A family of G-protein-coupled receptors that are specific for GALANIN and galanin peptides. They are generally considered to be coupled to the GI, INHIBITORY G-PROTEIN to meditate the neurological effects of galanin. Several subtypes of galanin receptors occur with differing specificities for the full length galanin, galanin peptide fragments, and galanin-like peptide.

Receptors, Gastrointestinal Hormone [M0018592]
Cell surface proteins that bind gastrointestinal hormones with high affinity and trigger intracellular changes influencing the behavior of cells. Most gastrointestinal hormones also act as neurotransmitters so these receptors are also present in the central and peripheral nervous systems.

Receptors, Glucagon [M0027213]
Cell surface receptors that bind glucagon with high affinity and trigger intracellular changes which influence the behavior of cells. Activation of glucagon receptors causes a variety of effects; the best understood is the initiation of a complex enzymatic cascade in the liver which ultimately increases the availability of glucose to body organs.

Receptors, Glucocorticoid [M0018594]
Cytoplasmic proteins that specifically bind glucocorticoids and mediate their cellular effects. The glucocorticoid receptor-glucocorticoid complex acts in the nucleus to induce transcription of DNA. Glucocorticoids were named for their actions on blood glucose concentration, but they have equally important effects on protein and fat metabolism. Cortisol is the most important example.

Receptors, Glutamate [M0026504]
Cell-surface proteins that bind glutamate and trigger changes which influence the behavior of cells. Glutamate receptors include ionotropic receptors (AMPA, kainate, and N-methyl-D-aspartate receptors), which directly control ion channels, and metabotropic receptors which act through second messenger systems. Glutamate receptors are the most common mediators of fast excitatory synaptic transmission in the central nervous system. They have also been implicated in the mechanisms of memory and of many diseases.

Receptors, Glycine [M0027191]
Cell surface receptors that bind glycine with high affinity and trigger intracellular changes which influence the behavior of cells. Glycine receptors in the central nervous system have an intrinsic chloride channel and are usually inhibitory.

Receptors, Gonadotropin [M0018597]
Those protein complexes or molecular sites on the surfaces of gonadal and other sensitive cells that bind gonadotropins and thereby modify the functions of those cells; hCG, LH, and FOLLICLE STIMULATING HORMONE are the major specific gonadotropins.

Receptors, Granulocyte Colony-Stimulating Factor [M0024705]
Receptors that bind and internalize GRANULOCYTE COLONY-STIMULATING FACTOR. Their MW is believed to be 150 kD. These receptors are found mainly on a subset of myelomonocytic cells.

Receptors, Granulocyte-Macrophage Colony-Stimulating Factor [M0024704]
Receptors that bind and internalize the granulocyte-macrophage stimulating factor. Their MW is believed to be 84 kD. The most mature myelomonocytic cells, specifically human neutrophils, macrophages, and eosinophils, express the highest number of affinity receptors for this growth factor.

Receptors, Growth Factor [M0027150]
Cell surface receptors that bind growth or trophic factors with high affinity, triggering intracellular responses which influence the growth, differentiation, or survival of cells.

Receptors, Guanylate Cyclase-Coupled [M0477283]
A class of cellular membrane receptors that either have an intrinsic guanylate cyclase activity or are closely coupled to specific guanylate cyclases within the cell.

Receptors, Histamine [M0018598]
Cell-surface proteins that bind histamine and trigger intracellular changes influencing the behavior of cells. Histamine receptors are widespread in the central nervous system and in peripheral tissues. Three types have been recognized and designated H1, H2, and H3. They differ in pharmacology, distribution, and mode of action.

Receptors, Histamine H1 [M0018600]
A class of histamine receptors discriminated by their pharmacology and mode of action. Most histamine H1 receptors operate through the inositol phosphate/diacylglycerol second messenger system. Among the many responses mediated by these receptors are smooth muscle contraction, increased vascular permeability, hormone release, and cerebral glyconeogenesis. (From Biochem Soc Trans 1992 Feb;20(1):122-5)

Receptors, Histamine H2 [M0018601]
A class of histamine receptors discriminated by their pharmacology and mode of action. Histamine H2 receptors act via G-proteins to stimulate adenylate cyclase. Among the many responses mediated by these receptors are gastric acid secretion, smooth muscle relaxation, inotropic and chronotropic effects on heart muscle, and inhibition of lymphocyte function. (From Biochem Soc Trans 1992 Feb;20(1):122-5)

Receptors, Histamine H3 [M0027296]
A class of histamine receptors discriminated by their pharmacology and mode of action. Histamine H3 receptors were first recognized as inhibitory autoreceptors on histamine-containing nerve terminals and have since been shown to regulate the release of several neurotransmitters in the central and peripheral nervous systems. (From Biochem Soc Trans 1992 Feb;20(1):122-5)

Receptors, HIV [M0024114]
Cellular receptors that bind the human immunodeficiency virus that causes AIDS. Included are CD4 ANTIGENS, found on T4 lymphocytes, and monocytes/macrophages, which bind to the HIV ENVELOPE PROTEIN GP120.

Receptors, Hypothalamic Release-Inhibiting Hormones [M0027198]

Receptors, Hypothalamic Releasing Hormones [M0027199]

Receptors, IgE [M0026487]
Specific molecular sites on the surface of B- and T-lymphocytes which combine with IgEs. Two subclasses exist: low affinity receptors (Fc epsilon RII) and high affinity receptors (Fc epsilon RI).

Receptors, IgG [M0026482]
Specific molecular sites on the surface of various cells, including B-lymphocytes and macrophages, that combine with IMMUNOGLOBULIN Gs. Three subclasses exist: Fc gamma RI (the CD64 antigen, a low affinity receptor), Fc gamma RII (the CD32 antigen, a high affinity receptor), and Fc gamma RIII (the CD16 antigen, a low affinity receptor).

Receptors, Immunologic [M0018602]
Cell surface molecules on cells of the immune system that specifically bind surface molecules or messenger molecules and trigger changes in the behavior of cells. Although these receptors were first identified in the immune system, many have important functions elsewhere.

Receptors, Interferon [M0026506]
Specific molecular sites or structures on or in cells with which interferons react or to which they bind in order to modify the function of the cells. Interferons exert their pleiotropic effects through two different receptors. alpha- and beta-interferon crossreact with common receptors, while gamma-interferon initiates its biological effects through its own specific receptor system.

Receptors, Interleukin [M0027328]
Cell surface proteins that bind interleukins and trigger intracellular changes influencing the behavior of cells.

Receptors, Interleukin-1 [M0026507]
Cell surface receptors that are specific for INTERLEUKIN-1. Included under this heading are signaling receptors, non-signaling receptors and accessory proteins required for receptor signaling. Signaling from interleukin-1 receptors occurs via interaction with SIGNAL TRANSDUCING ADAPTOR PROTEINS such as MYELOID DIFFERENTIATION FACTOR 88.

Receptors, Interleukin-1 Type I [M0264510]
An interleukin-1 receptor subtype that is involved in signaling cellular responses to INTERLEUKIN-1ALPHA and INTERLEUKIN-1BETA. The binding of this receptor to its ligand causes its favorable interaction with INTERLEUKIN-1 RECEPTOR ACCESSORY PROTEIN and the formation of an activated receptor complex.

Receptors, Interleukin-1 Type II [M0259861]
An interleukin-1 receptor subtype that competes with the INTERLEUKIN-1 RECEPTOR TYPE I for binding to INTERLEUKIN-1ALPHA and INTERLEUKIN-1BETA. The interleukin-1 type II receptor appears to lack signal transduction capability. Therefore it may act as a "decoy" receptor that modulates the activity of its ligands. Both membrane-bound and soluble forms of the receptor have been identified.

Receptors, Interleukin-10 [M0222565]
Cell surface receptors for INTERLEUKIN-10. They exist as a tetramer of two alpha chains (INTERLEUKIN-10 RECEPTOR ALPHA CHAIN) and two beta chains (INTERLEUKIN-10 RECEPTOR BETA CHAIN). Signaling from interleukin-10 receptors occurs through their interaction with JANUS KINASES.

Receptors, Interleukin-11 [M0200404]
Cell surface receptors that are specific for INTERLEUKIN-11. They consist of heterodimers of the INTERLEUKIN-11 RECEPTOR ALPHA SUBUNIT and the CYTOKINE RECEPTOR GP130.

Receptors, Interleukin-12 [M0232275]
Cell surface receptors for INTERLEUKIN-12. They exist as dimers of beta 1 and beta 2 subunits. Signaling from interleukin-12 receptors occurs through their interaction with JANUS KINASES.

Receptors, Interleukin-13 [M0219132]
Cell surface receptors for INTERLEUKIN-13. Included under this heading are the INTERLEUKIN-13 RECEPTOR ALPHA-2 CHAIN which is a monomeric receptor and the TYPE-II INTERLEUKIN-4 RECEPTOR which has specificity for both INTERLEUKIN-4 and INTERLEUKIN-13.

Receptors, Interleukin-15 [M0250533]
Cell surface receptors for INTERLEUKIN-15. They are widely-distributed heterotrimeric proteins consisting of the INTERLEUKIN-15 RECEPTOR ALPHA SUBUNIT, the INTERLEUKIN-2,15 RECEPTOR BETA SUBUNIT, and the INTERLEUKIN RECEPTOR COMMON GAMMA-CHAIN.

Receptors, Interleukin-16 [M0495828]
Cell surface receptors for INTERLEUKIN-16. Although initial studies have identified CD4 ANTIGENS as receptors for interleukin-16, the fact that cells from KNOCKOUT MICE which lack CD4 antigen are responsive to IL-16 indicate that are at least 2 distinct receptors subtypes.

Receptors, Interleukin-17 [M0495833]
Cell surface receptors for INTERLEUKIN-17. Several subtypes of receptors have been found, each with its own in specificity for interleukin-17 subtype.

Receptors, Interleukin-18 [M0495862]
Cell surface receptors for INTERLEUKIN-18 found on a variety of cell types including MACROPHAGES; NEUTROPHILS; NK CELLS; ENDOTHELIAL CELLS; and SMOOTH MUSCLE CELLS. They are formed as a heterodimer of alpha and beta subunits.

Receptors, Interleukin-2 [M0023684]
Receptors present on activated T-LYMPHOCYTES and B-LYMPHOCYTES that are specific for INTERLEUKIN-2 and play an important role in LYMPHOCYTE ACTIVATION. They are heterotrimeric proteins consisting of the INTERLEUKIN-2 RECEPTOR ALPHA SUBUNIT, the INTERLEUKIN-2 RECEPTOR BETA SUBUNIT, and the INTERLEUKIN RECEPTOR COMMON GAMMA-CHAIN.

Receptors, Interleukin-21 [M0373670]
Cell surface receptors for INTERLEUKIN-21. They are heterodimeric proteins found on DENDRITIC CELLS and LYMPHOCYTES that consist of the INTERLEUKIN-21 RECEPTOR ALPHA SUBUNIT and the CYTOKINE RECEPTOR COMMON BETA SUBUNIT.

Receptors, Interleukin-3 [M0024702]
High affinity receptors for INTERLEUKIN-3. They are found on early HEMATOPOIETIC PROGENITOR CELLS; progenitors of MYELOID CELLS; EOSINOPHILS; and BASOPHILS. Interleukin-3 receptors are formed by the dimerization of the INTERLEUKIN-3 RECEPTOR ALPHA SUBUNIT and the CYTOKINE RECEPTOR COMMON BETA SUBUNIT.

Receptors, Interleukin-4 [M0029620]
Receptors present on a wide variety of hematopoietic and non-hematopoietic cell types that are specific for INTERLEUKIN-4. They are involved in signaling a variety of immunological responses related to allergic INFLAMMATION including the differentiation of TH2 CELLS and the regulation of IMMUNOGLOBULIN E production. Two subtypes of receptors exist and are referred to as the TYPE I INTERLEUKIN-4 RECEPTOR and the TYPE II INTERLEUKIN-4 RECEPTOR. Each receptor subtype is defined by its unique subunit composition.

Receptors, Interleukin-4, Type I [M0495349]
An interleukin-4 receptor subtype that is found predominantly on hematopoietic cells. It is a heterodimer of the INTERLEUKIN-4 RECEPTOR ALPHA SUBUNIT and the INTERLEUKIN RECEPTOR COMMON GAMMA-CHAIN.

Receptors, Interleukin-4, Type II [M0495350]
An interleukin receptor subtype found on both hematopoietic and non-hematopoietic cells. It is a membrane-bound heterodimer that contains the INTERLEUKIN-4 RECEPTOR ALPHA SUBUNIT and the INTERLEUKIN-13 RECEPTOR ALPHA1 SUBUNIT. Although commonly referred to as the interleukin-4 type-II receptor this receptor has specificity for both INTERLEUKIN-4 and INTERLEUKIN-13

Receptors, Interleukin-5 [M0159503]
Cell surface receptors that are specific for INTERLEUKIN-5. They are heterodimeric proteins consisting of the INTERLEUKIN-5 RECEPTOR ALPHA SUBUNIT and the CYTOKINE RECEPTOR COMMON BETA SUBUNIT. Signaling from interleukin-5 receptors can occur through interaction of their cytoplasmic domains with SYNTENINS.

Receptors, Interleukin-6 [M0029619]
Cell surface receptors that are specific for INTERLEUKIN-6. They are present on T-LYMPHOCYTES, mitogen-activated B-LYMPHOCYTES, and peripheral MONOCYTES. The receptors are heterodimers of the INTERLEUKIN-6 RECEPTOR ALPHA SUBUNIT and the CYTOKINE RECEPTOR GP130.

Receptors, Interleukin-7 [M0030040]
Cell surface receptors that are specific for INTERLEUKIN-7. They are present on T-LYMPHOCYTES and B-LYMPHOCYTE precursors. The receptors are heterodimeric proteins consisting of the INTERLEUKIN-5 RECEPTOR ALPHA SUBUNIT and the CYTOKINE RECEPTOR COMMON BETA SUBUNIT.

Receptors, Interleukin-8 [M0495662]
Cell surface receptors that are specific for INTERLEUKIN-8. Two specific receptor subtypes (type A and B) have been found and bind IL-8 with high affinity.

Receptors, Interleukin-8A [M0163849]
High-affinity G-protein-coupled receptors for INTERLEUKIN-8 present on NEUTROPHILS; MONOCYTES; and BASOPHILS.

Receptors, Interleukin-8B [M0226645]
High-affinity G-protein-coupled receptors for INTERLEUKIN-8 present on NEUTROPHILS; MONOCYTES; and T-LYMPHOCYTES. These receptors also bind the CXC CHEMOKINES: chemokine (C-X-C motif) ligand 2 and chemokine (C-X-C motif) ligand 6.

Receptors, Interleukin-9 [M0181171]
A cell surface receptor that specifically mediates the biological effects of INTERLEUKIN-9. The functional IL9 receptor signals through interaction of its cytoplasm domain with JANUS KINASES and requires the INTERLEUKIN RECEPTOR COMMON GAMMA SUBUNIT for activity.

Receptors, Invertebrate Peptide [M0027192]
Cell surface receptors for invertebrate peptide hormones or neuropeptides.

Receptors, Kainic Acid [M0027288]
Cell surface proteins that bind glutamate and directly gate ion channels. Kainic acid receptors were originally discriminated from other glutamate receptors by their affinity for the agonist kainic acid. Activation of kainic acid receptors is generally excitatory to cells. Subtypes have been cloned, and for some the traditional distinction from AMPA receptors may not apply.

Receptors, Laminin [M0026511]
Glycoprotein molecules on the surface of cells that react with or bind to laminin whose function allows the binding of epithelial cells to the basement membrane. The molecular weight of this high-affinity receptor is 67 kD.

Receptors, LDL [M0018606]
Receptors on the plasma membrane of nonhepatic cells that specifically bind LDL. The receptors are localized in specialized regions called coated pits. Hypercholesteremia is caused by an allelic genetic defect of three types: 1, receptors do not bind to LDL; 2, there is reduced binding of LDL; and 3, there is normal binding but no internalization of LDL. In consequence, entry of cholesterol esters into the cell is impaired and the intracellular feedback by cholesterol on 3-hydroxy-3-methylglutaryl CoA reductase is lacking.

Receptors, Lectin [M0018608]

Receptors, Leukocyte-Adhesion [M0024505]
Family of proteins associated with the capacity of LEUKOCYTES to adhere to each other and to certain substrata, e.g., the C3bi component of complement. Members of this family are the LYMPHOCYTE FUNCTION-ASSOCIATED ANTIGEN-1; (LFA-1), the MACROPHAGE-1 ANTIGEN; (Mac-1), and the INTEGRIN ALPHAXBETA2 or p150,95 leukocyte adhesion protein. They all share a common beta-subunit which is the CD18 antigen. All three of the above antigens are absent in inherited LEUKOCYTE-ADHESION DEFICIENCY SYNDROME, which is characterized by recurrent bacterial infections, impaired pus formation, and wound healing as well as abnormalities in a wide spectrum of adherence-dependent functions of granulocytes, monocytes, and lymphoid cells.

Receptors, Leukotriene [M0027271]
Cell-surface receptors that bind LEUKOTRIENES with high affinity and trigger intracellular changes influencing the behavior of cells. The leukotriene receptor subtypes have been tentatively named according to their affinities for the endogenous leukotrienes LTB4; LTC4; LTD4; and LTE4.

Receptors, Leukotriene B4 [M0027298]
A class of cell surface leukotriene receptors with a preference for leukotriene B4. Leukotriene B4 receptor activation influences chemotaxis, chemokinesis, adherence, enzyme release, oxidative bursts, and degranulation in polymorphonuclear leukocytes. There are at least two subtypes of these receptors. Some actions are mediated through the inositol phosphate and diacylglycerol second messenger systems.

Receptors, LH [M0018607]
Those protein complexes or molecular sites on the surfaces and cytoplasm of gonadal cells that bind luteinizing or chorionic gonadotropic hormones and thereby cause the gonadal cells to synthesize and secrete sex steroids. The hormone-receptor complex is internalized from the plasma membrane and initiates steroid synthesis.

Receptors, LHRH [M0018595]
Receptors with a 6-kDa protein on the surfaces of cells that secrete LUTEINIZING HORMONE or FOLLICLE STIMULATING HORMONE, usually in the adenohypophysis. LUTEINIZING HORMONE RH binds to these receptors, is endocytosed with the receptor and, in the cell, triggers the release of LUTEINIZING HORMONE or FOLLICLE STIMULATING HORMONE by the cell. These receptors are also found in rat gonads. INHIBINS prevent the binding of GnRH to its receptors.

Receptors, Lipoprotein [M0027310]
Cell surface proteins that bind lipoproteins with high affinity. Lipoprotein receptors in the liver and peripheral tissues mediate the regulation of plasma and cellular cholesterol metabolism and concentration. The receptors generally recognize the apolipoproteins of the lipoprotein complex, and binding is often a trigger for endocytosis.

Receptors, Lipoxin [M0444307]
Cell surface proteins that bind LIPOXINS with high affinity and trigger intracellular changes influencing the behavior of cells.

Receptors, Long-Acting Thyroid Stimulator [M0018628]
Receptors on the thyroid cells that bind the LONG-ACTING THYROID STIMULATOR or LATS, the abnormal immunoglobulins that consist of various anti-TSH receptors and anti-thyroid antibodies.

Receptors, Lymphocyte Homing [M0024736]
Cell surface glycoproteins on lymphocytes and other leukocytes that mediate adhesion to specialized blood vessels called high endothelial venules. Several different classes of lymphocyte homing receptors have been identified, and they appear to target different surface molecules (addressins) on high endothelial venules in different tissues. The adhesion plays a crucial role in the trafficking of lymphocytes.

Receptors, Lysophosphatidic Acid [M0203735]
A subfamily of lysophospholipid receptors with specificity for LYSOPHOSPHATIDIC ACIDS.

Receptors, Lysophospholipid [M0464103]
A family of G-protein-coupled receptors that bind to specific LYSOPHOSPHOLIPIDS such as lysophosphatidic acid and lysosphinglipids such as sphingosine-1-phosphate. They play an important role in the formation and function of the CARDIOVASCULAR SYSTEM.

Receptors, Lysosphingolipid [M0254581]
A subfamily of lysophospholipid receptors with specificity for LYSOSPHINGOLIPIDS such as sphingosine-1-phosphate and sphingosine phosphorylcholine.

Receptors, Mating Factor [M0138576]
A family of pheromone receptors that were initially discovered in SACCHAROMYCES CEREVISIAE as proteins necessary for fungal conjugation. Each mating factor receptor is expressed in HAPLOID CELLS of a single mating type.

Receptors, Melanocortin [M0230670]
A family of G-protein-coupled receptors that have specificity for MELANOCYTE-STIMULATING HORMONES and ADRENOCORTICOTROPIC HORMONE. There are several subtypes of melanocortin receptors, each having a distinct ligand specificity profile and tissue localization.

Receptors, Melatonin [M0096696]
A family of G-protein-coupled receptors that are specific for and mediate the effects of MELATONIN. Activation of melatonin receptors has been associated with decreased intracellular CYCLIC AMP and increased hydrolysis of PHOSPHOINOSITIDES.

Receptors, Menotropin [M0018596]

Receptors, Metabotropic Glutamate [M0027290]
Cell surface proteins that bind glutamate and act through G-proteins to influence second messenger systems. Several types of metabotropic glutamate receptors have been cloned. They differ in pharmacology, distribution, and mechanisms of action.

Receptors, Mineralocorticoid [M0027375]
Cytoplasmic proteins that specifically bind mineralocorticoids and mediate their cellular effects. The receptor with its bound ligand acts in the nucleus to induce transcription of specific segments of DNA. Mineralocorticoids were named for their actions on extracellular electrolyte concentrations. The most important example is aldosterone.

Receptors, Mitogen [M0018609]
Glycoprotein molecules on the surface of B- and T-lymphocytes, that react with molecules of antilymphocyte sera, lectins, and other agents which induce blast transformation of lymphocytes.

Receptors, Monoiodotyrosine [M0018629]

Receptors, Muscarinic [M0018610]
One of the two major classes of cholinergic receptors. Muscarinic receptors were originally defined by their preference for MUSCARINE over NICOTINE. There are several subtypes (usually M1, M2, M3....) that are characterized by their cellular actions, pharmacology, and molecular biology.

Receptors, N-Acetylglucosamine [M0158849]
Cell surface receptors that bind to ACETYLGLUCOSAMINE.

Receptors, N-Methyl-D-Aspartate [M0024713]
A class of ionotropic glutamate receptors characterized by affinity for N-methyl-D-aspartate. NMDA receptors have an allosteric binding site for glycine which must be occupied for the channel to open efficiently and a site within the channel itself to which magnesium ions bind in a voltage-dependent manner. The positive voltage dependence of channel conductance and the high permeability of the conducting channel to calcium ions (as well as to monovalent cations) are important in excitotoxicity and neuronal plasticity.

Receptors, Narcotic [M0018579]

Receptors, Nerve Growth Factor [M0026512]
Cell surface receptors that bind NERVE GROWTH FACTOR; (NGF) and a NGF-related family of neurotrophic factors that includes neurotrophins, BRAIN-DERIVED NEUROTROPHIC FACTOR and CILIARY NEUROTROPHIC FACTOR.

Receptors, Neurokinin-1 [M0027226]
A class of cell surface receptors for tachykinins with a preference for substance P. Neurokinin-1 (NK-1) receptors have been cloned and are members of the G protein coupled receptor superfamily. They are found on many cell types including central and peripheral neurons, smooth muscle cells, acinar cells, endothelial cells, fibroblasts, and immune cells.

Receptors, Neurokinin-2 [M0027227]
A class of cell surface receptors for tachykinins that prefers neurokinin A; (NKA, substance K, neurokinin alpha, neuromedin L), neuropeptide K; (NPK); or neuropeptide gamma over other tachykinins. Neurokinin-2 (NK-2) receptors have been cloned and are similar to other G-protein coupled receptors.

Receptors, Neurokinin-3 [M0027228]
A class of cell surface receptors for tachykinins that prefers neurokinin B (neurokinin beta, neuromedin K) over other tachykinins. Neurokinin-3 (NK-3) receptors have been cloned and are members of the G-protein coupled receptor superfamily. They have been found in the central nervous system and in peripheral tissues.

Receptors, Neuropeptide [M0027194]
Cell surface receptors that bind specific neuropeptides with high affinity and trigger intracellular changes influencing the behavior of cells. Many neuropeptides are also hormones outside of the nervous system.

Receptors, Neuropeptide Y [M0026513]
Cell surface proteins that bind neuropeptide Y with high affinity and trigger intracellular changes which influence the behavior of cells.

Receptors, Neurotensin [M0027214]
Cell surface proteins that bind neurotensin with high affinity and trigger intracellular changes which influence the behavior of cells. Neurotensin and neurotensin receptors are found in the central nervous system and in the periphery.

Receptors, Neurotransmitter [M0027153]
Cell surface receptors that bind signalling molecules released by neurons and convert these signals into intracellular changes influencing the behavior of cells. Neurotransmitter is used here in its most general sense, including not only messengers that act to regulate ion channels, but also those which act on second messenger systems and those which may act at a distance from their release sites. Included are receptors for neuromodulators, neuroregulators, neuromediators, and neurohumors, whether or not located at synapses.

Receptors, Nicotinic [M0018611]
One of the two major classes of cholinergic receptors. Nicotinic receptors were originally distinguished by their preference for nicotine over muscarine. They are generally divided into muscle-type and neuronal-type (previously ganglionic) based on pharmacology, molecular biology, and biophysical properties of the channels.

Receptors, Normorphine [M0018577]

Receptors, Notch [M0176572]
A family of conserved cell surface receptors that contain EPIDERMAL GROWTH FACTOR repeats in their extracellular domain and ANKYRIN repeats in their cytoplasmic domains. The cytoplasmic domain of notch receptors is released upon ligand binding and translocates to the CELL NUCLEUS where it acts as transcription factor.

Receptors, Nuclear [M0027372]

Receptors, Odorant [M0027221]
Proteins, usually projecting from the cilia of olfactory receptor neurons, that specifically bind odorant molecules and trigger responses in the neurons. The large number of different odorant receptors appears to arise from several gene families or subfamilies rather than from DNA rearrangement.

Receptors, Oncostatin M [M0176944]
Cell surface receptors with specificity for ONCOSTATIN M. Two subtypes of receptors have been identified and are defined by their subunit composition.

Receptors, Oncostatin M, Type II [M0176942]
A subtype of oncostatin receptors that are formed by dimerization of ONCOSTATIN M RECEPTOR BETA SUBUNIT and CYTOKINE RECEPTOR GP130. They are activated specifically by ONCOSTATIN M and signal through interaction of their cytoplasmic domains with JANUS KINASES.

Receptors, Opioid [M0018578]
Cell membrane proteins that bind opioids and trigger intracellular changes which influence the behavior of cells. The endogenous ligands for opioid receptors in mammals include three families of peptides, the enkephalins, endorphins, and dynorphins. The receptor classes include mu, delta, and kappa receptors. Sigma receptors bind several psychoactive substances, including certain opioids, but their endogenous ligands are not known.

Receptors, Opioid, delta [M0026499]
A class of opioid receptors recognized by its pharmacological profile. Delta opioid receptors bind endorphins and enkephalins with approximately equal affinity and have less affinity for dynorphins.

Receptors, Opioid, kappa [M0026510]
A class of opioid receptors recognized by its pharmacological profile. Kappa opioid receptors bind dynorphins with a higher affinity than endorphins which are themselves preferred to enkephalins.

Receptors, Opioid, mu [M0026475]
A class of opioid receptors recognized by its pharmacological profile. Mu opioid receptors bind, in decreasing order of affinity, endorphins, dynorphins, met-enkephalin, and leu-enkephalin. They have also been shown to be molecular receptors for morphine.

Receptors, OSM-LIF [M0185326]
Cell surface receptors formed from the dimerization of LIF RECEPTOR ALPHA SUBUNIT with CYTOKINE RECEPTOR GP130. Although originally described as receptors for LEUKEMIA INHIBITORY FACTOR these receptors also bind the closely-related protein ONCOSTATIN M and are referred to as both LIF receptors and type I oncostatin M receptors.

Receptors, OX40 [M0223546]
A tumor necrosis family receptor with specificity for OX40 LIGAND. It is found on the surface of activated T-LYMPHOCYTES where it plays a role in enhancing cytokine production and proliferation of CD4-POSITIVE T-LYMPHOCYTES. Signaling by the activated receptor occurs through its association with TNF RECEPTOR-ASSOCIATED FACTORS.

Receptors, Oxidized LDL [M0273143]
A group of cell-surface receptors for oxidatively modified LOW-DENSITY LIPOPROTEINS. The group includes certain SCAVENGER RECEPTORS that contribute to the pathogenesis of ATHEROSCLEROSIS by uptake of oxidized LDL.

Receptors, Oxytocin [M0027230]
Cell surface proteins that bind oxytocin with high affinity and trigger intracellular changes which influence the behavior of cells. Oxytocin receptors in the uterus and the mammary glands mediate the hormone's stimulation of contraction and milk ejection. The presence of oxytocin and oxytocin receptors in neurons of the brain probably reflects an additional role as a neurotransmitter.

Receptors, Pancreatic Hormone [M0027212]
Cell surface proteins that bind pancreatic hormones with high affinity and trigger intracellular changes which influence the behavior of cells. These include receptors for glucagon (secreted by alpha cells), insulin (secreted by beta cells), somatostatin (secreted by delta cells), and pancreatic peptide (secreted by PP cells). Some of these hormones and receptors also support neurotransmission.

Receptors, Parathyroid Hormone [M0027197]
Cell surface proteins that bind PARATHYROID HORMONE with high affinity and trigger intracellular changes which influence the behavior of cells. Parathyroid hormone receptors on BONE; KIDNEY; and gastrointestinal cells mediate the hormone's role in calcium and phosphate homeostasis.

Receptors, Pattern Recognition [M0479617]
A large family of cell surface receptors that bind conserved molecular structures present in pathogens. They play important roles in host defense by mediating cellular responses to pathogens.

Receptors, Peptide [M0027184]
Cell surface receptors that bind peptide messengers with high affinity and regulate intracellular signals which influence the behavior of cells.

Receptors, Phencyclidine [M0026514]
Specific sites or molecular structures on cell membranes or in cells with which phencyclidine reacts or to which it binds to elicit the specific response of the cell to phencyclidine. Studies have demonstrated the presence of multiple receptor sites for PCP. These are the PCP/sigma site, which binds both PCP and psychotomimetic opiates but not certain antipsychotics, and the PCP site, which selectively binds PCP analogs.

Receptors, Pheromone [M0004021]
Cell surface receptors that respond to PHEROMONES.

Receptors, Pituitary Adenylate Cyclase-Activating Polypeptide [M0180540]
A family of G-protein-coupled receptors that share significant homology with GLUCAGON RECEPTORS. They bind PITUITARY ADENYLATE CYCLASE ACTIVATING POLYPEPTIDE with high affinity and trigger intracellular changes that influence the behavior of CELLS.

Receptors, Pituitary Adenylate Cyclase-Activating Polypeptide, Type I [M0180536]
A pituitary adenylate cyclase-activating peptide receptor subtype that is found in the HYPOTHALAMUS; BRAIN STEM; PITUITARY GLAND; ADRENAL GLAND; PANCREAS; and TESTES and has a high affinity only for PACAP.

Receptors, Pituitary Hormone [M0018612]
Cell surface proteins that bind pituitary hormones with high affinity and trigger intracellular changes influencing the behavior of cells. Since many pituitary hormones are also released by neurons as neurotransmitters, these receptors are also found in the nervous system.

Receptors, Pituitary Hormone Release Inhibiting Hormones [M0027200]

Receptors, Pituitary Hormone-Regulating Hormone [M0027202]
Cell surface receptors that bind the hypothalamic hormones regulating pituitary cell differentiation, proliferation, and hormone synthesis and release, including the pituitary-releasing and release-inhibiting hormones. The pituitary hormone-regulating hormones are also released by cells other than hypothalamic neurons, and their receptors also occur on non-pituitary cells, especially brain neurons, where their role is less well understood. Receptors for dopamine, which is a prolactin release-inhibiting hormone as well as a common neurotransmitter, are not included here.

Receptors, Pituitary Hormone-Releasing Hormone [M0027201]

Receptors, Platelet-Derived Growth Factor [M0026515]
Specific receptors on cell membranes that react with PLATELET-DERIVED GROWTH FACTOR, its analogs, or antagonists. The alpha PDGF receptor (RECEPTOR, PLATELET-DERIVED GROWTH FACTOR ALPHA) and the beta PDGF receptor (RECEPTOR, PLATELET-DERIVED GROWTH FACTOR BETA) are the two principle types of PDGF receptors. Activation of the protein-tyrosine kinase activity of the receptors occurs by ligand-induced dimerization or heterodimerization of PDGF receptor types.

Receptors, Polymeric Immunoglobulin [M0028447]
Specialized Fc receptors (RECEPTORS, FC) for polymeric immunoglobulins, which mediate transcytosis of polymeric IMMUNOGLOBULIN A and IMMUNOGLOBULIN M into external secretions. They are found on the surfaces of epithelial cells and hepatocytes. After binding to IMMUNOGLOBULIN A, the receptor-ligand complex undergoes endocytosis, transport by vesicle, and secretion into the lumen by exocytosis. Before release, the part of the receptor (SECRETORY COMPONENT) that is bound to IMMUNOGLOBULIN A is proteolytically cleaved from its transmembrane tail. (From Rosen et al., The Dictionary of Immunology, 1989)

Receptors, Presynaptic [M0026716]
Neurotransmitter receptors located on or near presynaptic terminals or varicosities. Presynaptic receptors which bind transmitter molecules released by the terminal itself are termed AUTORECEPTORS.

Receptors, Progesterone [M0018613]
Specific proteins found in or on cells of progesterone target tissues that specifically combine with progesterone. The cytosol progesterone-receptor complex then associates with the nucleic acids to initiate protein synthesis. There are two kinds of progesterone receptors, A and B. Both are induced by estrogen and have short half-lives.

Receptors, Prolactin [M0018614]
Labile proteins on or in prolactin-sensitive cells that bind prolactin initiating the cells' physiological response to that hormone. Mammary casein synthesis is one of the responses. The receptors are also found in placenta, liver, testes, kidneys, ovaries, and other organs and bind and respond to certain other hormones and their analogs and antagonists. This receptor is related to the growth hormone receptor.

Receptors, Prostaglandin [M0018615]
Cell surface receptors that bind prostaglandins with high affinity and trigger intracellular changes which influence the behavior of cells. Prostaglandin receptor subtypes have been tentatively named according to their relative affinities for the endogenous prostaglandins. They include those which prefer prostaglandin D2 (DP receptors), prostaglandin E2 (EP1, EP2, and EP3 receptors), prostaglandin F2-alpha (FP receptors), and prostacyclin (IP receptors).

Receptors, Prostaglandin E [M0027272]
Cell surface receptors which bind prostaglandins with a high affinity and trigger intracellular changes which influence the behavior of cells. Prostaglandin E receptors prefer prostaglandin E2 to other endogenous prostaglandins. They are subdivided into EP1, EP2, and EP3 types based on their effects and their pharmacology.

Receptors, Prostaglandin H2 [M0131404]

Receptors, Proteinase-Activated [M0445102]
A class of receptors that are activated by the action of PROTEINASES. The most notable examples are the THROMBIN RECEPTORS. The receptors contain cryptic ligands that are exposed upon the selective proteolysis of specific N-terminal cleavage sites.

Receptors, Purinergic [M0018617]
Cell surface proteins that bind PURINES with high affinity and trigger intracellular changes which influence the behavior of cells. The best characterized classes of purinergic receptors in mammals are the P1 receptors, which prefer ADENOSINE, and the P2 receptors, which prefer ATP or ADP.

Receptors, Purinergic P1 [M0027234]
A class of cell surface receptors that prefers ADENOSINE to other endogenous purines. Purinergic P1 receptors are widespread in the body including the cardiovascular, respiratory, immune, and nervous systems. There are at least two pharmacologically distinguishable types (A1 and A2, or Ri and Ra). The methylxanthines, e.g., CAFFEINE, bind to these receptors, but also have other unrelated effects.

Receptors, Purinergic P2 [M0027237]
A class of cell surface receptors for purines that prefer ATP or ADP over adenosine. P2 purinergic receptors are widespread in the periphery and in the central and peripheral nervous system. Subtypes have been proposed, usually designated P2 x, y, z, and t. P2x receptors may mediate fast synaptic transmission by ATP. The ADP-preferring P2t receptors in platelets stimulate aggregation.

Receptors, Retinoic Acid [M0027390]
Proteins in the nucleus or cytoplasm that specifically bind RETINOIC ACID or RETINOL and trigger changes in the behavior of cells. Retinoic acid receptors, like steroid receptors, are ligand-activated transcription regulators. Several types have been recognized.

Receptors, Scavenger [M0102200]
A large group of structurally diverse cell surface receptors that mediate endocytic uptake of modified LIPOPROTEINS. Scavenger receptors are expressed by MYELOID CELLS and some ENDOTHELIAL CELLS, and were originally characterized based on their ability to bind acetylated LOW-DENSITY LIPOPROTEINS. They can also bind a variety of other polyanionic ligand. Certain scavenger receptors can internalize micro-organisms as well as apoptotic cells.

Receptors, Serotonin [M0018620]
Cell-surface proteins that bind SEROTONIN and trigger intracellular changes which influence the behavior of cells. Several types of serotonin receptors have been recognized which differ in their pharmacology, molecular biology, and mode of action.

Receptors, Serotonin, 5-HT1 [M0444696]
A subclass of G-protein coupled SEROTONIN receptors that couple preferentially to GI-GO G-PROTEINS resulting in decreased intracellular CYCLIC AMP levels.

Receptors, Serotonin, 5-HT2 [M0018621]
A subclass of G-protein coupled SEROTONIN receptors that couple preferentialy to the GQ-G11 G-PROTEINS resulting in increased intracellular levels of INOSITOL PHOSPHATES and free CALCIUM.

Receptors, Serotonin, 5-HT3 [M0244242]
A subclass of serotonin receptors that form cation channels and mediate signal transduction by depolarizing the cell membrane. The cation channels are formed from 5 receptor subunits. When stimulated the receptors and allow the selective passage of SODIUM; POTASSIUM; and CALCIUM.

Receptors, Serotonin, 5-HT4 [M0248720]
A subtype of G-protein-coupled SEROTONIN receptors that preferentially couple to GS STIMULATORY G-PROTEINS resulting in increased intracellular CYCLIC AMP. Several isoforms of the receptor exist due to ALTERNATIVE SPLICING of its mRNA.

Receptors, Serotonin, 5-HT4L [M0248715]

Receptors, Serotonin, 5-HT4S [M0248716]

Receptors, sigma [M0026516]
A class of cell surface receptors recognized by its pharmacological profile. Sigma receptors were originally considered to be opioid receptors because they bind certain synthetic opioids. However they also interact with a variety of other psychoactive drugs, and their endogenous ligand is not known (although they can react to certain endogenous steroids). Sigma receptors are found in the immune, endocrine, and nervous systems, and in some peripheral tissues.

Receptors, Sincalide [M0018565]

Receptors, Somatomammotropin [M0392783]

Receptors, Somatomedin [M0026477]
Cell surface receptors that bind somatomedins and trigger intracellular changes which influence the behavior of cells. Studies have disclosed two types of receptors for this family of peptide hormones. The type I receptor is homologous to the insulin receptor and has tyrosine kinase activity. The type II receptor is identical to the mannose-6-phosphate receptor which is important in trafficking of lysosomal enzymes.

Receptors, Somatostatin [M0026517]
Cell surface proteins that bind somatostatin and trigger intracellular changes which influence the behavior of cells. Somatostatin is a hypothalamic hormone, a pancreatic hormone, and a central and peripheral neurotransmitter. Activated somatostatin receptors on pituitary cells inhibit the release of growth hormone; those on endocrine and gastrointestinal cells regulate the absorption and utilization of nutrients; and those on neurons mediate somatostatin's role as a neurotransmitter.

Receptors, Somatotropin [M0018623]
Cell surface proteins that bind GROWTH HORMONE with high affinity and trigger intracellular changes influencing the behavior of cells. Activation of growth hormone receptors regulates amino acid transport through cell membranes, RNA translation to protein, DNA transcription, and protein and amino acid catabolism in many cell types. Many of these effects are mediated indirectly through stimulation of the release of somatomedins.

Receptors, Steroid [M0018626]
Proteins found usually in the cytoplasm or nucleus that specifically bind steroid hormones and trigger changes influencing the behavior of cells. The steroid receptor-steroid hormone complex regulates the transcription of specific genes.

Receptors, Tachykinin [M0027225]
Cell surface proteins that bind tachykinins with high affinity and trigger intracellular changes influencing the behavior of cells. Three classes of tachykinin receptors have been characterized, the NK-1; NK-2; and NK-3; which prefer, respectively, substance P, neurokinin A (substance K, neurokinin alpha, neuromedin L), and neurokinin B (neurokinin beta, neuromedin K).

Receptors, Thrombin [M0027406]
A family of proteinase-activated receptors that are specific for THROMBIN. They are found primarily on PLATELETS and on ENDOTHELIAL CELLS. Activation of thrombin receptors occurs through the proteolytic action of THROMBIN, which cleaves the N-terminal peptide from the receptor to reveal a new N-terminal peptide that is a cryptic ligand for the receptor. The receptors signal through HETEROTRIMERIC GTP-BINDING PROTEINS. Small synthetic peptides that contain the unmasked N-terminal peptide sequence can also activate the receptor in the absence of proteolytic activity.

Receptors, Thrombopoietin [M0495063]
Cell surface receptors that are specific for THROMBOPOIETIN. They signal through interaction with JANUS KINASES such as JANUS KINASE 2.

Receptors, Thromboxane [M0026518]
Cell surface proteins that bind THROMBOXANES with high affinity and trigger intracellular changes influencing the behavior of cells. Some thromboxane receptors act via the inositol phosphate and diacylglycerol second messenger systems.

Receptors, Thromboxane A2 [M0444662]

Receptors, Thromboxane A2, Prostaglandin H2 [M0026519]
A subclass of eicosanoid receptors that have specificity for THROMBOXANE A2 and PROSTAGLANDIN H2.

Receptors, Thyroid Hormone [M0018630]
Specific high affinity binding proteins for THYROID HORMONES in target cells. They are usually found in the nucleus and regulate DNA transcription. These receptors are activated by hormones that leads to transcription, cell differentiation, and growth suppression. Thyroid hormone receptors are encoded by two genes (GENES, ERBA): erbA-alpha and erbA-beta for alpha and beta thyroid hormone receptors, respectively.

Receptors, Thyrotropin [M0018635]
Cell surface proteins that bind pituitary THYROTROPIN (also named thyroid stimulating hormone or TSH) and trigger intracellular changes of the target cells. TSH receptors are present in the nervous system and on target cells in the thyroid gland. Autoantibodies to TSH receptors are implicated in thyroid diseases such as GRAVES DISEASE and Hashimoto disease (THYROIDITIS, AUTOIMMUNE).

Receptors, Thyrotropin-Releasing Hormone [M0027211]
Cell surface receptors that bind thyrotropin releasing hormone (TRH) with high affinity and trigger intracellular changes which influence the behavior of cells. Activated TRH receptors in the anterior pituitary stimulate the release of thyrotropin (thyroid stimulating hormone, TSH); TRH receptors on neurons mediate neurotransmission by TRH.

Receptors, Thyroxine [M0018632]

Receptors, TIE [M0209740]
A family of structurally-related tyrosine kinase receptors that are expressed predominantly in ENDOTHELIAL CELLS and are essential for development of BLOOD VESSELS (NEOVASCULARIZATION, PHYSIOLOGIC). The name derives from the fact that they are tyrosine kinases that contain Ig and EGF domains.

Receptors, TNF-Related Apoptosis-Inducing Ligand [M0279402]
Tumor necrosis factor receptor family members that are widely expressed and play a role in regulation of peripheral immune responses and APOPTOSIS. The receptors are specific for TNF-RELATED APOPTOSIS-INDUCING LIGAND and signal via conserved death domains that associate with specific TNF RECEPTOR-ASSOCIATED FACTORS in the CYTOPLASM.

Receptors, Transferrin [M0018636]
Membrane glycoproteins found in high concentrations on iron-utilizing cells. They specifically bind iron-bearing transferrin, are endocytosed with its ligand and then returned to the cell surface where transferrin without its iron is released.

Receptors, Transforming Growth Factor beta [M0027330]
Cell-surface proteins that bind transforming growth factor beta and trigger changes influencing the behavior of cells. Two types of transforming growth factor receptors have been recognized. They differ in affinity for different members of the transforming growth factor beta family and in cellular mechanisms of action.

Receptors, Triiodothyronine [M0018631]

Receptors, Tryptamine [M0018622]

Receptors, Tumor Necrosis Factor [M0027329]
Cell surface receptors that bind TUMOR NECROSIS FACTORS and trigger changes which influence the behavior of cells.

Receptors, Tumor Necrosis Factor, Member 10a [M0492515]

Receptors, Tumor Necrosis Factor, Member 10b [M0492514]

Receptors, Tumor Necrosis Factor, Member 10c [M0492559]
A secreted tumor necrosis factor receptor family member that has specificity for TNF-RELATED APOPTOSIS-INDUCING LIGAND. It plays a modulating role in activation of APOPTOSIS signaling.

Receptors, Tumor Necrosis Factor, Member 10d [M0492520]
A receptor subtype found in human.

Receptors, Tumor Necrosis Factor, Member 14 [M0277012]
A novel member of the tumor-necrosis factor receptor family that can also mediate HERPES SIMPLEX VIRUS TYPE 1 entry into cells. It has specificity for TUMOR NECROSIS FACTOR LIGAND SUPERFAMILY MEMBER 14 and the homotrimeric form of LYMPHOTOXIN-ALPHA. The receptor is abundantly expressed on T-LYMPHOCYTES and may play a role in regulating lymphocyte activation. Signaling by the activated receptor occurs through its association with TNF RECEPTOR-ASSOCIATED FACTORS.

Receptors, Tumor Necrosis Factor, Member 25 [M0273582]
A tumor necrosis factor receptor subtype with specificity for TUMOR NECROSIS FACTOR LIGAND SUPERFAMILY MEMBER 15. It is found in tissues containing LYMPHOCYTES and may play a role in regulating lymphocyte homeostasis and APOPTOSIS. The activated receptor signals via a conserved death domain that associates with specific TNF RECEPTOR-ASSOCIATED FACTORS in the CYTOPLASM.

Receptors, Tumor Necrosis Factor, Member 6b [M0299445]
A secreted tumor necrosis factor receptor family member that has specificity FAS LIGAND and TUMOR NECROSIS FACTOR LIGAND SUPERFAMILY MEMBER 14. It plays a modulating role in tumor necrosis factor signaling pathway.

Receptors, Tumor Necrosis Factor, Type I [M0232359]
A tumor necrosis factor receptor subtype that has specificity for TUMOR NECROSIS FACTOR ALPHA and LYMPHOTOXIN ALPHA. It is constitutively expressed in most tissues and is a key mediator of tumor necrosis factor signaling in the vast majority of cells. The activated receptor signals via a conserved death domain that associates with specific TNF RECEPTOR-ASSOCIATED FACTORS in the CYTOPLASM.

Receptors, Tumor Necrosis Factor, Type II [M0232370]
A tumor necrosis factor receptor subtype that is expressed primarily in IMMUNE SYSTEM cells. It has specificity for membrane-bound form of TUMOR NECROSIS FACTORS and mediates intracellular-signaling through TNF RECEPTOR ASSOCIATED FACTORS.

Receptors, Vascular Endothelial Growth Factor [M0185203]
A family of closely related RECEPTOR PROTEIN-TYROSINE KINASES that bind vascular endothelial growth factors. They share a cluster of seven extracellular Ig-like domains which are important for ligand binding. They are highly expressed in vascular endothelial cells and are critical for the physiological and pathological growth, development and maintenance of blood and lymphatic vessels.

Receptors, Vasoactive Intestinal Peptide [M0027188]
Cell surface proteins that bind VASOACTIVE INTESTINAL PEPTIDE; (VIP); with high affinity and trigger intracellular changes which influence the behavior of cells.

Receptors, Vasoactive Intestinal Peptide, Type II [M0180538]
A pituitary adenylate cyclase-activating peptide receptor subtype found in LYMPHOCYTES. It binds both PACAP and VASOACTIVE INTESTINAL PEPTIDE and regulates immune responses.

Receptors, Vasoactive Intestinal Polypeptide, Type I [M0180537]
A pituitary adenylate cyclase-activating polypeptide receptor subtype that binds both PACAP and VASOACTIVE INTESTINAL PEPTIDE. It is found predominately in the BRAIN.

Receptors, Vasopressin [M0026520]
Specific molecular sites or proteins on or in cells to which VASOPRESSINS bind or interact in order to modify the function of the cells. Two types of vasopressin receptor exist, the V1 receptor in the vascular smooth muscle and the V2 receptor in the kidneys. The V1 receptor can be subdivided into V1a and V1b (formerly V3) receptors.

Receptors, Very Late Antigen [M0024506]
Members of the integrin family appearing late after T-cell activation. They are a family of proteins initially identified at the surface of stimulated T-cells, but now identified on a variety of cell types. At least six VLA antigens have been identified as heterodimeric adhesion receptors consisting of a single common beta-subunit and different alpha-subunits.

Receptors, Virus [M0018638]
Specific molecular components of the cell capable of recognizing and interacting with a virus, and which, after binding it, are capable of generating some signal that initiates the chain of events leading to the biological response.

Receptors, Vitronectin [M0028407]
Receptors such as INTEGRIN ALPHAVBETA3 that bind VITRONECTIN with high affinity and play a role in cell migration. They also bind FIBRINOGEN; VON WILLEBRAND FACTOR; osteopontin; and THROMBOSPONDINS.

Recombinant Fusion Proteins [M0018640]
Recombinant proteins produced by the GENETIC TRANSLATION of fused genes formed by the combination of NUCLEIC ACID REGULATORY SEQUENCES of one or more genes with the protein coding sequences of one or more genes.

Recombinant Human Growth Hormone (Mammalian) [M0397867]
Mammalian-cell derived recombinant human growth hormone.

Recombinant Proteins [M0018641]
Proteins prepared by recombinant DNA technology.

Recombinases [M0137939]
A broad category of enzymes that are involved in the process of GENETIC RECOMBINATION.

Recormon [M0028768]

Recoverin [M0146724]
A neuronal calcium-sensor protein that is found in ROD PHOTORECEPTORS and CONE PHOTORECEPTORS. It interacts with RHODOPSIN KINASE in a Ca2+ dependent manner and plays an important role in PHOTOTRANSDUCTION.

RecQ Helicases [M0178844]
A family of structurally-related DNA helicases that play an essential role in the maintenance of genome integrity. RecQ helicases were originally discovered in E COLI and are highly conserved across both prokaryotic and eukaryotic organisms. Genetic mutations that result in loss of RecQ helicase activity gives rise to disorders that are associated with CANCER predisposition and premature aging.

RecQ2 Helicase [M0493665]

RecQ3 Helicase [M0493666]

RecQ4 Helicase [M0414891]

RecQ5 Helicase [M0336412]

RecQL Helicase [M0239601]

Reduced Glutathione [M0009389]

Regenerating Islet-Derived 1 alpha Protein [M0109966]

Regenerating Islet-Derived 1 beta Protein [M0109967]

Relaxin [M0018751]
A water-soluble polypeptide (molecular weight approximately 8,000) extractable from the corpus luteum of pregnancy. It produces relaxation of the pubic symphysis and dilation of the uterine cervix in certain animal species. Its role in the human pregnant female is uncertain. (Dorland, 28th ed)

Relaxin B [M0018752]

Relefact TRH [M0021499]

Renin [M0018776]
An enzyme which is secreted by the KIDNEY and is formed from prorenin in plasma and kidney. The enzyme cleaves the Leu-Leu bond in ANGIOTENSINOGEN to generate ANGIOTENSIN I. This enzyme was formerly listed as EC 3.4.99.19.

Renin Substrate Tetradecapeptide [M0001209]

Renitec [M0007332]

Renokinase [M0333863]

Replication Protein A [M0178006]
A single-stranded DNA-binding protein that is found in EUKARYOTIC CELLS. It is required for DNA REPLICATION; DNA REPAIR; and GENETIC RECOMBINATION.

Replication Protein C [M0199689]
A DNA-binding protein that consists of 5 polypeptides and plays an essential role in DNA REPLICATION in eukaryotes. It binds DNA PRIMER-template junctions and recruits PROLIFERATING CELL NUCLEAR ANTIGEN and DNA POLYMERASES to the site of DNA synthesis.

Replication Protein C, Subunit 1 [M0481935]

Replication Protein C, Subunit 2 [M0199685]

Replication Protein C, Subunit 3 [M0359015]

Replication Protein C, Subunit 4 [M0359016]

Replication Protein C, Subunit 5 [M0359017]

Repressor Molecules [M0018810]

Repressor Proteins [M0018809]
Proteins which are normally bound to the operator locus of an operon, thereby preventing transcription of the structural genes. In enzyme induction, the substrate of the inducible enzyme binds to the repressor protein, causing its release from the operator and freeing the structural genes for transcription. In enzyme repression, the end product of the enzyme sequence binds to the free repressor protein, the resulting complex then binds to the operator and prevents transcription of the structural genes.

Reptilase [M0333033]

Reptilian Proteins [M0386064]
Proteins obtained from species of REPTILES.

Resistin [M0378392]
A 12-kDa cysteine-rich polypeptide hormone secreted by FAT CELLS in the ADIPOSE TISSUE. It is the founding member of the resistin-like molecule (RELM) hormone family. Resistin suppresses the ability of INSULIN to stimulate cellular GLUCOSE uptake.

Resolvases [M0272325]

Restasis [M0452877]
Opthalmic emulsion

Restriction Endonuclease RsrI [M0023465]

Reticulin [M0018933]
A scleroprotein fibril consisting mostly of type III collagen. Reticulin fibrils are extremely thin, with a diameter of between 0.5 and 2 um. They are involved in maintaining the structural integrity in a variety of organs.

Retinal Dehydrogenase [M0078673]
A metalloflavoprotein enzyme involved the metabolism of VITAMIN A, this enzyme catalyzes the oxidation of RETINAL to RETINOIC ACID, using both NAD+ and FAD coenzymes. It also acts on both the 11-trans- and 13-cis-forms of RETINAL.

Retinoblastoma Protein [M0024673]
Product of the retinoblastoma tumor suppressor gene. It is a nuclear phosphoprotein hypothesized to normally act as an inhibitor of cell proliferation. Rb protein is absent in retinoblastoma cell lines. It also has been shown to form complexes with the adenovirus E1A protein, the SV40 T antigen, and the human papilloma virus E7 protein.

Retinoblastoma-Like Protein p107 [M0477276]
A negative regulator of the CELL CYCLE that undergoes PHOSPHORYLATION by CYCLIN-DEPENDENT KINASES. It contains a conserved pocket region that binds E2F4 TRANSCRIPTION FACTOR and interacts with viral ONCOPROTEINS such as POLYOMAVIRUS TUMOR ANTIGENS; ADENOVIRUS E1A PROTEINS; and PAPILLOMAVIRUS E7 PROTEINS.

Retinoblastoma-Like Protein p130 [M0477275]
A negative regulator of the CELL CYCLE that undergoes PHOSPHORYLATION by CYCLIN-DEPENDENT KINASES. RBL2 contains a conserved pocket region that binds E2F4 TRANSCRIPTION FACTOR and E2F5 TRANSCRIPTION FACTOR. RBL2 also interacts with viral ONCOPROTEINS such as POLYOMAVIRUS TUMOR ANTIGENS; ADENOVIRUS E1A PROTEINS; and PAPILLOMAVIRUS E7 PROTEINS.

Retinoic Acid-Binding Proteins [M0027389]

Retinoid Binding Protein, F-Type [M0018964]

Retinoid X Receptor alpha [M0196514]
A nuclear transcription factor. Heterodimerization with PPAR GAMMA is important in regulation of GLUCOSE metabolism and CELL GROWTH PROCESSES.

Retinoid X Receptor beta [M0196515]

Retinoid X Receptor gamma [M0196516]
A nuclear transcription factor. Heterodimerization with PPAR ALPHA is important to metabolism of LIPIDS.

Retinoid X Receptors [M0196521]
A subtype of RETINOIC ACID RECEPTORS that are specific for 9-cis-retinoic acid which function as nuclear TRANSCRIPTION FACTORS that regulate multiple signalling pathways.

Retinol O-Fatty-Acyltransferase [M0078688]
An enzyme that catalyzes the acyl group transfer of acyl COENZYME A to RETINOL to generate COENZYME A and a retinyl ester.

Retinol Stearate Synthetase [M0078686]

Retinol-Binding Proteins [M0018965]
Proteins which bind with RETINOL. The retinol-binding protein found in plasma has an alpha-1 mobility on electrophoresis and a molecular weight of about 21 kDa. The protein has one binding site for retinol and is responsible for the transport of Vitamin A. The retinol-protein complex (MW=80-90 kDa) circulates in plasma in the form of a protein-protein complex with prealbumin. The retinol-binding protein found in tissue has a molecular weight of 14 kDa and carries retinol as a non-covalently-bound ligand.

Retinol-Palmitate Synthetase [M0078687]

Retroviridae Proteins [M0018984]
Proteins from the family Retroviridae. The most frequently encountered member of this family is the Rous sarcoma virus protein.

Retroviridae Proteins, Oncogenic [M0024050]
Retroviral proteins that have the ability to transform cells. They can induce sarcomas, leukemias, lymphomas, and mammary carcinomas. Not all retroviral proteins are oncogenic.

Retrovirus Proteins [M0018985]

rev Protein [M0024075]

Reverse Triiodothyronine 5'-Deiodinase [M0011632]

RGS Proteins [M0328278]
A large family of evolutionarily conserved proteins that function as negative regulators of HETEROTRIMERIC GTP-BINDING PROTEINS. RGS PROTEINS act by increasing the GTPase activity of the G alpha subunit of a heterotrimeric GTP-binding protein, causing it to revert to its inactive (GDP-bound) form.

Rheumatoid Factor [M0019016]
Antibodies found in adult RHEUMATOID ARTHRITIS patients that are directed against GAMMA-CHAIN IMMUNOGLOBULINS.

Rhinathiol [M0372313]

Rho Factor [M0019036]
A protein which effects termination of RNA synthesis during the genetic transcription process by dissociating the ternary transcription complex RNA;-RNA POLYMERASE DNA at the termination of a gene.

rho GTP-Binding Proteins [M0328280]
A large family of MONOMERIC GTP-BINDING PROTEINS that are involved in regulation of actin organization, gene expression and cell cycle progression. This enzyme was formerly listed as EC 3.6.1.47.

Rho(D) Immune Globulin [M0027215]
Immunizing agent containing IMMUNOGLOBULIN G anti-Rho(D) used for preventing Rh immunization in Rh-negative individuals exposed to Rh-positive red blood cells.

Rho(D) Immune Globulin Intravenous (Human) [M0462971]

rhoA GTP-Binding Protein [M0328282]
A RHO GTP-BINDING PROTEIN involved in regulating signal transduction pathways that control assembly of focal adhesions and actin stress fibers. This enzyme was formerly listed as EC 3.6.1.47.

rhoB GTP-Binding Protein [M0328283]
A GTP-BINDING PROTEIN involved in regulating a signal transduction pathway that controls assembly of focal adhesions and actin stress fibers. This enzyme was formerly listed as EC 3.6.1.47.

Rhodopsin [M0019047]
A photoreceptor protein found in retinal rods. It is a complex formed by the binding of RETINALDEHYDE, the oxidized form of retinol, to the protein OPSIN and undergoes a series of complex reactions in response to visible light resulting in the transmission of nerve impulses to the brain.

Rhodopsin Kinase [M0078698]
A PROTEIN-SERINE-THREONINE KINASE that is found in PHOTORECEPTORS. It mediates light-dependent PHOSPHORYLATION of RHODOPSIN and plays an important role in PHOTOTRANSDUCTION.

Rhodopsins, Microbial [M0375052]
Rhodopsin molecules found in microorganisms such as ARCHAEA and PROTEOBACTERIA.

RhoGAM [M0373303]

Rhophylac [M0476304]

RhsI Endonuclease [M0023454]

Riboflavin Synthase [M0019066]
An enzyme that catalyzes the formation of riboflavin from two molecules of 6,7-dimethyl-8-ribityllumazine, utilizing a four-carbon fragment from one molecule which is transferred to the second molecule. EC 2.5.1.9.

Ribonuclease F1 [M0009697]

Ribonuclease F2 [M0009698]

Ribonuclease H, Calf Thymus [M0025740]
A ribonuclease that specifically cleaves the RNA moiety of RNA:DNA hybrids. It has been isolated from a wide variety of prokaryotic and eukaryotic organisms (particularly calf thymus) as well as retroviruses. EC 3.1.26.4.

Ribonuclease III [M0078718]
An endoribonuclease that is specific for double-stranded RNA. It plays a role in POST-TRANSCRIPTIONAL RNA PROCESSING of pre-RIBOSOMAL RNA and a variety of other RNA structures that contain double-stranded regions.

Ribonuclease P [M0078728]
An RNA-containing enzyme that plays an essential role in tRNA processing by catalyzing the endonucleolytic cleavage of TRANSFER RNA precursors. It removes the extra 5'-nucleotides from tRNA precursors to generate mature tRNA molecules.

Ribonuclease ST [M0009699]

Ribonuclease T1 [M0009696]
An enzyme catalyzing the endonucleolytic cleavage of RNA at the 3'-position of a guanylate residue. EC 3.1.27.3.

Ribonuclease, Pancreatic [M0019067]
An enzyme that catalyzes the endonucleolytic cleavage of pancreatic ribonucleic acids to 3'-phosphomono- and oligonucleotides ending in cytidylic or uridylic acids with 2',3'-cyclic phosphate intermediates. EC 3.1.27.5.

Ribonucleases [M0019070]
Enzymes that catalyze the hydrolysis of ester bonds within RNA. EC 3.1.-.

Ribonucleoprotein, U1 Small Nuclear [M0026429]
A nuclear RNA-protein complex that plays a role in RNA processing. In the nucleoplasm, the U1 snRNP along with other small nuclear ribonucleoproteins (U2, U4-U6, and U5) assemble into SPLICEOSOMES that remove introns from pre-mRNA by splicing. The U1 snRNA forms base pairs with conserved sequence motifs at the 5'-splice site and recognizes both the 5'- and 3'-splice sites and may have a fundamental role in aligning the two sites for the splicing reaction.

Ribonucleoprotein, U2 Small Nuclear [M0026430]
A nuclear RNA-protein complex that plays a role in RNA processing. In the nucleoplasm, the U2 snRNP along with other small nuclear ribonucleoproteins (U1, U4-U6, and U5) assemble into SPLICEOSOMES that remove introns from pre-mRNA by splicing. The U2 snRNA forms base pairs with conserved sequence motifs at the branch point, which associates with a heat- and RNAase-sensitive factor in an early step of splicing.

Ribonucleoprotein, U4-U6 Small Nuclear [M0026433]
A nuclear RNA-protein complex that plays a role in RNA processing. In the nucleoplasm, the U4-U6 snRNP along with the U5 snRNP preassemble into a single 25S particle that binds to the U1 and U2 snRNPs and the substrate to form mature SPLICEOSOMES. There is also evidence for the existence of individual U4 or U6 snRNPs in addition to their organization as a U4-U6 snRNP.

Ribonucleoprotein, U5 Small Nuclear [M0026434]
A nuclear RNA-protein complex that plays a role in RNA processing. In the nucleoplasm, the U5 snRNP along with U4-U6 snRNP preassemble into a single 25S particle that binds to the U1 and U2 snRNPs and the substrate to form SPLICEOSOMES.

Ribonucleoprotein, U7 Small Nuclear [M0328059]
This ribonucleoprotein particle, composed of U7 snRNA, Sm core protein, and U7 snRNP-specific proteins, is involved in the 3'end processing of histone premessenger RNAs.

Ribonucleoproteins [M0019071]
Complexes of RNA-binding proteins with ribonucleic acids (RNA).

Ribonucleoproteins, Small Cytoplasmic [M0328065]
Complexes of scRNA (RNA, SMALL CYTOPLASMIC) and protein found in the cytoplasm. An example is SIGNAL RECOGNITION PARTICLE.

Ribonucleoproteins, Small Nuclear [M0026426]
Highly conserved nuclear RNA-protein complexes that function in RNA processing in the nucleus, including pre-mRNA splicing and pre-mRNA 3'-end processing in the nucleoplasm, and pre-rRNA processing in the nucleolus (see RIBONUCLEOPROTEINS, SMALL NUCLEOLAR).

Ribonucleoproteins, Small Nucleolar [M0328069]
Nucleolar RNA-protein complexes that function in pre-ribosomal RNA processing.

Ribonucleoside Diphosphate Reductase [M0019072]
An enzyme of the oxidoreductase class that catalyzes the formation of 2'-deoxyribonucleotides from the corresponding ribonucleotides using NADPH as the ultimate electron donor. The deoxyribonucleoside diphosphates are used in DNA synthesis. (From Dorland, 27th ed) EC 1.17.4.1.

Ribonucleotide Reductases [M0019075]

Ribose-Phosphate Pyrophosphokinase [M0019079]
An enzyme that catalyzes the formation of phosphoribosyl pyrophosphate from ATP and ribose-5-phosphate. EC 2.7.6.1.

Ribosomal Protein S6 [M0090726]
A ribosomal protein that may play a role in controlling cell growth and proliferation. It is a major substrate of RIBOSOMAL PROTEIN S6 KINASES and plays a role in regulating the translation (TRANSLATION, GENETIC) of RNAs that contain an RNA 5' TERMINAL OLIGOPYRIMIDINE SEQUENCE.

Ribosomal Protein S6 Kinases [M0029535]
A family of protein serine/threonine kinases which act as intracellular signalling intermediates. Ribosomal protein S6 kinases are activated through phosphorylation in response to a variety of HORMONES and INTERCELLULAR SIGNALING PEPTIDES AND PROTEINS. Phosphorylation of RIBOSOMAL PROTEIN S6 by enzymes in this class results in increased expression of 5' TOP MRNAS. Although specific for RIBOSOMAL PROTEIN S6 members of this class of kinases can act on a number of substrates within the cell. The immunosuppressant SIROLIMUS inhibits the activation of ribosomal protein S6 kinases.

Ribosomal Protein S6 Kinases, 70-kDa [M0417009]
A family of ribosomal protein S6 kinases that are considered the major physiological kinases for RIBOSOMAL PROTEIN S6. Unlike RIBOSOMAL PROTEIN S6 KINASES, 90KDa the proteins in this family are sensitive to the inhibitory effects of RAPAMYCIN and contain a single kinase domain. They are referred to as 70kDa proteins, however ALTERNATIVE SPLICING of mRNAs for proteins in this class also results in 85kDa variants being formed.

Ribosomal Protein S6 Kinases, 90-kDa [M0223389]
A family of ribosomal protein S6 kinases that are structurally distinguished from RIBOSOMAL PROTEIN S6 KINASES, 70-KDA by their apparent molecular size and the fact they contain two functional kinase domains. Although considered RIBOSOMAL PROTEIN S6 KINASES, members of this family are activated via the MAP KINASE SIGNALING SYSTEM and have been shown to act on a diverse array of substrates that are involved in cellular regulation such as RIBOSOMAL PROTEIN S6 and CAMP RESPONSE ELEMENT-BINDING PROTEIN.

Ribosomal Proteins [M0019080]
Proteins found in ribosomes. They are believed to have a catalytic function in reconstituting biologically active ribosomal subunits.

Ribulose-Bisphosphate Carboxylase [M0019084]
A copper protein that catalyzes the formation of 2 moles of 3-phosphoglycerate from ribulose 1,5-biphosphate in the presence of carbon dioxide. It utilizes oxygen instead of carbon dioxide to form 2-phosphoglycollate and 3-phosphoglycerate. EC 4.1.1.39.

Ricin A Chain [M0019089]

Ricin B Chain [M0019090]

Ricin D [M0019091]

Ricin I [M0019092]

Rifamycin Polyketide Synthase [M0333181]

Rifathyroin [M0021500]

Ristocetin [M0019134]
An antibiotic mixture of two components, A and B, obtained from Nocardia lurida (or the same substance produced by any other means). It is no longer used clinically because of its toxicity. It causes platelet agglutination and blood coagulation and is used to assay those functions in vitro.

Ristomycin [M0357324]

RMI 71782 [M0373515]

RNA Cap-Binding Proteins [M0093749]
Proteins that specifically bind to RNA CAPS and form nuclear cap binding protein complexes. In addition to stabilizing the 5' end of mRNAs, they serve a diverse array of functions such as enhancing mRNA transport out of the CELL NUCLEUS and regulating MRNA TRANSLATION in the CYTOPLASM.

RNA Helicases [M0029997]
A family of proteins that promote unwinding of RNA during splicing and translation. EC 2.7.7.-.

RNA Ligase (ATP) [M0017244]
An enzyme that catalyzes the conversion of linear RNA to a circular form by the transfer of the 5'-phosphate to the 3'-hydroxyl terminus. It also catalyzes the covalent joining of two polyribonucleotides in phosphodiester linkage. EC 6.5.1.3.

RNA Nucleotidyltransferases [M0019142]
Enzymes that catalyze the template-directed incorporation of ribonucleotides into an RNA chain. EC 2.7.7.-.

RNA Polymerase I [M0019145]
A DNA-dependent RNA polymerase present in bacterial, plant, and animal cells. The enzyme functions in the nucleolar structure and transcribes DNA into RNA. It has different requirements for cations and salts than RNA polymerase II and III and is not inhibited by alpha-amanitin. EC 2.7.7.6.

RNA Polymerase II [M0019146]
A DNA-dependent RNA polymerase present in bacterial, plant, and animal cells. It functions in the nucleoplasmic structure and transcribes DNA into RNA. It has different requirements for cations and salt than RNA polymerase I and is strongly inhibited by alpha-amanitin. EC 2.7.7.6.

RNA Polymerase III [M0019147]
A DNA-dependent RNA polymerase present in bacterial, plant, and animal cells. It functions in the nucleoplasmic structure where it transcribes DNA into RNA. It has specific requirements for cations and salt and has shown an intermediate sensitivity to alpha-amanitin in comparison to RNA polymerase I and II. EC 2.7.7.6.

RNA Polymerase Sigma 54 [M0184075]
A DNA-directed RNA polymerase found in BACTERIA. It is a holoenzyme that consists of multiple subunits including sigma factor 54.

RNA Polymerase Sigma Factor H [M0019834]

RNA Replicase [M0019157]
An enzyme that catalyses RNA-template-directed extension of the 3'- end of an RNA strand by one nucleotide at a time, and can initiate a chain de novo. (Enzyme Nomenclature, 1992, p293)

RNA, Transfer, Amino Acyl [M0019198]
Intermediates in protein biosynthesis. The compounds are formed from amino acids, ATP and transfer RNA, a reaction catalyzed by aminoacyl tRNA synthetase. They are key compounds in the genetic translation process.

RNA-Binding Protein EWS [M0087091]
A ubiquitous hnRNP protein found in the CELL NUCLEUS and the CYTOPLASM. Translocations that result in the formation of fusion proteins containing parts of RNA-binding protein EWS may play a role in neoplastic processes such as Ewing Sarcoma (SARCOMA, EWING'S).

RNA-Binding Protein FUS [M0087111]
A multifunctional heterogeneous-nuclear ribonucleoprotein that may play a role in homologous DNA pairing and recombination. The N-terminal portion of protein is a potent transcriptional activator, while the C terminus is required for RNA binding. The name FUS refers to the fact that genetic recombination events result in fusion oncogene proteins (ONCOGENE PROTEINS, FUSION) that contain the N-terminal region of this protein. These fusion proteins have been found in myxoid liposarcoma (LIPOSARCOMA, MYXOID) and acute myeloid leukemia.

RNA-Binding Proteins [M0025317]
Proteins that bind to RNA molecules. Included here are RIBONUCLEOPROTEINS and other proteins whose function is to bind specifically to RNA.

RNA-Directed DNA Polymerase [M0018988]
An enzyme that synthesizes DNA on an RNA template. It is encoded by the pol gene of retroviruses and by certain retrovirus-like elements. EC 2.7.7.49.

RNA-Induced Silencing Complex [M0406104]
A multicomponent, ribonucleoprotein complex that cleaves specific mRNAs (RNA, MESSENGER) which are targeted for degradation by homologous dsRNAs (RNA, DOUBLE-STRANDED) during the process of RNA INTERFERENCE. It includes siRNA (RNA, SMALL INTERFERING) that is generated from the specific dsRNA.

RNase Apl [M0009700]

RNase Pch 1 [M0009701]

Ro 22-8181 [M0331743]

Ro-23-6019 [M0373553]

Roferon-A [M0023694]

Rowasa [M0029393]

RP 7293 [M0372895]

RpoN1 Protein [M0466785]

RpoN2 Protein [M0184069]

RS-94991-298 [M0373295]

RT7 Antigens [M0026543]

RU 49637 [M0218190]

Rubredoxins [M0019299]
A class of iron-sulfur proteins that contains one iron coordinated to the sulfur atom of four cysteine residues. (McGraw-Hill Dictionary of Scientific and Technical Terms, 5th ed)

RX-783006 [M0111602]

Ryanodine Receptor Calcium Release Channel [M0029444]
A tetrameric calcium release channel in the SARCOPLASMIC RETICULUM membrane of smooth muscle cells, acting oppositely to SARCOPLASMIC RETICULUM CALCIUM-TRANSPORTING ATPASES. It is important in skeletal and cardiac excitation-contraction coupling and studied by using RYANODINE. Abnormalities are implicated in ARRHYTHMIA and MUSCULAR DISEASES.

Ryanodine Receptors [M0029445]

RyR1 [M0029448]

RyR2 [M0029446]

RyR3 [M0029447]

S Amet [M0431776]

S-Adenosylhomocysteine [M0019321]
5'-S-(3-Amino-3-carboxypropyl)-5'-thioadenosine. Formed from S-adenosylmethionine after transmethylation reactions.

S-Adenosylmethionine [M0019322]
Physiologic methyl radical donor involved in enzymatic transmethylation reactions and present in all living organisms. It possesses anti-inflammatory activity and has been used in treatment of chronic liver disease. (From Merck, 11th ed)

S-Adenosylmethionine Sulfate Tosylate [M0019323]

S-Methylmethionine [M0022810]

S-Phase Kinase-Associated Proteins [M0446233]
A family of structurally-related proteins that were originally identified by their ability to complex with cyclin proteins (CYCLINS). They share a common domain that binds specifically to F-BOX MOTIFS. They take part in SKP CULLIN F-BOX PROTEIN LIGASES, where they can bind to a variety of F-BOX PROTEINS.

S100 Proteins [M0014662]
A family of highly acidic calcium-binding proteins found in large concentration in the brain and believed to be glial in origin. They are also found in other organs in the body. They have in common the EF-hand motif (EF HAND MOTIFS) found on a number of calcium binding proteins. The name of this family derives from the property of being soluble in a 100% saturated ammonium sulfate solution.

S1P1 Receptor [M0239352]

S1P2 Receptor [M0376168]

S1P3 Receptor [M0190191]

S1P4 Receptor [M0361615]

S1P5 Receptor [M0363774]

Sabril [M0333927]

Saccharide-Mediated Cell Adhesion Molecules [M0024222]

Saccharomyces cerevisiae Proteins [M0385173]
Proteins obtained from the species SACCHAROMYCES CEREVISIAE. The function of specific proteins from this organism are the subject of intense scientific interest and have been used to derive basic understanding of the functioning similar proteins in higher eukaryotes.

Saccharopine Dehydrogenase (NAD+, L-Glutamate Forming) [M0456330]

Saccharopine Dehydrogenase (NAD+, L-Lysine Forming) [M0456328]

Saccharopine Dehydrogenase (NADP+, L-Glutamate Forming) [M0456331]

Saccharopine Dehydrogenase (NADP+, L-Lysine Forming) [M0456329]

Saccharopine Dehydrogenases [M0019332]
Amine oxidoreductases that use either NAD+ (EC 1.5.1.7) or NADP+ (EC 1.5.1.8) as an acceptor to form L-LYSINE or NAD+ (EC 1.5.1.9) or NADP+ (EC 1.5.1.10) as an acceptor to form L-GLUTAMATE. Deficiency of this enzyme causes HYPERLYSINEMIAS.

Sacrosidase [M0445458]

Saizen [M0028846]

Salivary Proteins [M0019380]
Proteins found in SALIVA and the SALIVARY GLANDS. Some show enzymatic activity, but their composition varies in different individuals.

Salmine [M0019382]

Samyr [M0439893]

Sandimmun Neoral [M0025282]

Sandimmune [M0025283]

Sandoglobulin [M0025526]

Sandostatine [M0023528]

Saposin A [M0165439]

Saposin B [M0063222]

Saposin C [M0097524]

Saposin D [M0160576]

Saposins [M0463564]
A group of four homologous sphingolipid activator proteins that are formed from proteolytic cleavage of a common protein precursor molecule referred to as prosaposin.

Saralasin [M0019423]
An octapeptide analog of angiotensin II (bovine) with amino acids 1 and 8 replaced with sarcosine and alanine, respectively. It is a highly specific competitive inhibitor of angiotensin II.

Saralasin Acetate [M0019422]

Saralasin Acetate, Anhydrous [M0329698]

Sarcocystatin [M0024324]

Sarcoglycans [M0463342]
A family of transmembrane dystrophin-associated proteins that plays a role in the membrane association of the DYSTROPHIN-ASSOCIATED PROTEIN COMPLEX. Mutations abolishing the expression of sarcoglycans result in LIMB-GIRDLE MUSCULAR DYSTROPHY.

Sarcoplasmic Reticulum Calcium-Transporting ATPase 1 [M0367364]

Sarcoplasmic Reticulum Calcium-Transporting ATPase 2 [M0367365]

Sarcoplasmic Reticulum Calcium-Transporting ATPase 2a [M0471108]

Sarcoplasmic Reticulum Calcium-Transporting ATPase 3 [M0401967]

Sarcoplasmic Reticulum Calcium-Transporting ATPases [M0367363]
Calcium-transporting ATPases that catalyze the active transport of CALCIUM into the SARCOPLASMIC RETICULUM vesicles from the CYTOPLASM. They are primarily found in MUSCLE CELLS and play a role in the relaxation of MUSCLES.

Sarcosine [M0019445]
An amino acid intermediate in the metabolism of choline.

Sarcosine Dehydrogenase [M0078933]
A LIVER mitochondrial matrix flavoenzyme that catalyzes the oxidation of SARCOSINE to GLYCINE and FORMALDEHYDE. Mutation in the enzyme causes sarcosinemia, a rare autosomal metabolic defect characterized by elevated levels of SARCOSINE in BLOOD and URINE.

Sarcosine Hydrochloride [M0329700]

Sarcosine Monosodium Salt [M0329699]

Sarcosine Oxidase [M0088310]
A FLAVOPROTEIN, this enzyme catalyzes the oxidation of SARCOSINE to GLYCINE; FORMALDEHYDE; and HYDROGEN PEROXIDE (H2O2).

Sarkolysin [M0013331]

SC-18862 [M0357395]

Scavenger Receptors, Class A [M0479144]
A family of scavenger receptors that mediate the influx of LIPIDS into MACROPHAGES and are involved in FOAM CELL formation.

Scavenger Receptors, Class A, Type I [M0481418]

Scavenger Receptors, Class A, Type I-II [M0481422]

Scavenger Receptors, Class A, Type II [M0481421]

Scavenger Receptors, Class B [M0479145]
A family of scavenger receptors that are predominately localized to CAVEOLAE of the PLASMA MEMBRANE and bind HIGH DENSITY LIPOPROTEINS.

Scavenger Receptors, Class C [M0479146]
A family of scavenger receptors with broad polyanionic ligand binding properties that are expressed in embryonic insect MACROPHAGES.

Scavenger Receptors, Class C, Type I [M0481425]

Scavenger Receptors, Class D [M0479147]
A class of scavenger receptors that are specific for oxidized LOW-DENSITY LIPOPROTEINS and apoptotic cells. They are expressed almost exclusively in INTRACELLULAR MEMBRANES of MACROPHAGES.

Scavenger Receptors, Class E [M0479148]
A class of oxidized LDL receptors that contain LECTIN-like extracellular domains.

Scavenger Receptors, Class E, Type I [M0481427]

Scavenger Receptors, Class F [M0479149]
A group of structurally related scavenger receptors expressed predominately by ENDOTHELIAL CELLS. They-contain repeats of EPIDERMAL GROWTH FACTOR-like cysteine-rich motifs in their extracellular domains.

Scavenger Receptors, Macrophage [M0481458]

SCF(beta-TrCP) Ubiquitin Ligase [M0366198]

SCF(Fbw7) Ubiquitin Ligase [M0403106]

Sch-30500 [M0331789]

Schizosaccharomyces pombe Proteins [M0385174]
Proteins obtained from the species Schizosaccharomyces pombe. The function of specific proteins from this organism are the subject of intense scientific interest and have been used to derive basic understanding of the functioning similar proteins in higher eukaryotes.

Scleroproteins [M0019544]
Simple proteins characterized by their insolubility and fibrous structure. Within the body, they perform a supportive or protective function.

Scrapie Agent [M0027905]

Scrapie HaSp33-37 Protein [M0027907]

SecII Endonuclease [M0028381]

Secrepan [M0372648]

Secretin [M0019589]
A peptide hormone of about 27 amino acids from the duodenal mucosa that activates pancreatic secretion and lowers the blood sugar level. (USAN and the USP Dictionary of Drug Names, 1994, p597)

Secretin Citrate, Pig [M0329705]

Secretin Maleate, Pig [M0329704]

Secretin Pentacetate, Pig [M0329702]

Secretin Sulfate, Pig [M0329703]

Secretin, Pig [M0329701]

Secretin-KABI [M0372647]

Secretogranin II [M0492867]
A type of chromogranin which was initially characterized in the ANTERIOR PITUITARY. It is found in several species including human, rat, mouse, and others. Secretogranin II is an acidic protein of 559 to 586 amino acid residues that can stimulate DOPAMINE release from neurons and release of pituitary GONADOTROPINS.

Secretory Component [M0019591]
The extracellular moiety of the POLYMERIC IMMUNOGLOBULIN RECEPTOR found alone or complexed with IGA or IGM, in a variety of external secretions (tears, bile, colostrum.) Secretory component is derived by proteolytic cleavage of the receptor during transcytosis. When immunoglobulins IgA and IgM are bound to the receptor, during their transcytosis secretory component becomes covalently attached to them generating SECRETORY IMMUNOGLOBULIN A or secretory IMMUNOGLOBULIN M.

Secretory Leukocyte Peptidase Inhibitor [M0066112]
A proteinase inhibitor found in various BODILY SECRETIONS that coat mucosal surfaces such as SEMINAL PLASMA; CERVICAL MUCUS; and bronchial secretions. It plays a role in protecting epithelial tissues from LEUKOCYTE-derived serine proteases such as NEUTROPHIL ELASTASE.

Selectins [M0028489]
Family of cell adhesion molecules consisting of a lectin-like domain, an epidermal growth factor-like domain, and a variable number of domains that encode proteins homologous to complement-binding proteins. Selectins mediate the binding of leukocytes to the vascular endothelium. (From Dorland, 28th ed)

Selenium-Binding Proteins [M0111720]
A group of proteins that covalently attach to selenium or SELENIUM-containing compounds.

Selenocysteine [M0026231]
A naturally occurring amino acid in both eukaryotic and prokaryotic organisms. It is found in tRNAs and in the catalytic site of some enzymes. The genes for glutathione peroxidase and formate dehydrogenase contain the TGA codon, which codes for this amino acid.

Selenocysteine, DL-Isomer [M0329377]

Selenoglutathione Peroxidase [M0009391]

Selenomethionine [M0019607]
Diagnostic aid in pancreas function determination.

Selenomethionine Hydrochloride, (S)-Isomer [M0329716]

Selenomethionine Se 75 [M0019606]

Selenomethionine, (+,-)-Isomer [M0329714]

Selenomethionine, (R)-Isomer [M0329713]

Selenomethionine, (S)-Isomer [M0329715]

Selenoprotein P [M0110732]
An extracellular selenoprotein that contains most of the SELENIUM in PLASMA. Selenoprotein P functions as an antioxidant and appears to transport selenium from the LIVER to peripheral tissues.

Selenoprotein P1 [M0110733]

Selenoprotein R [M0479439]
A zinc-containing stereo-specific methionine sulfoxide reductase.

Selenoprotein W [M0479435]
A single SELENOCYSTEINE containing protein that binds reduced GLUTATHIONE and can act as an antioxidant.

Selenoproteins [M0110735]
Selenoproteins are proteins that specifically incorporate SELENOCYSTEINE into their amino acid chain. Most selenoproteins are enzymes with the selenocysteine residues being responsible for their catalytic functions.

Semaphorin-3A [M0222872]
The prototypical and most well-studied member of the semaphorin family. Semaphorin-3A is an axon-repulsive guidance cue for migrating neurons in the developing nervous system. It has so far been found only in vertebrates, and binds to NEUROPILIN-1/plexin complex receptors on growth cones. Like other class 3 semaphorins, it is a secreted protein.

Semaphorins [M0419969]
A family of proteins that mediate axonal guidance. Semaphorins act as repulsive cues for neuronal GROWTH CONES and bind to receptors on their filopodia. At least 20 different molecules have been described and divided into eight classes based on domain organization and species of origin. Classes 1 and 2 are invertebrate, classes 3-7 are vertebrate, and class V are viral. Semaphorins may be secreted (classes 2, 3, and V), transmembrane (classes 1, 4, 5, and 6), or membrane-anchored (class 7). All semaphorins possess a common 500-amino acid extracellular domain which is critical for receptor binding and specificity, and is also found in plexins and scatter factor receptors. Their C termini are class-specific and may contain additional sequence motifs.

Sembrina [M0474252]

Seminal Plasma Proteins [M0069840]
Proteins found in SEMEN. Major seminal plasma proteins are secretory proteins from the male sex accessory glands, such as the SEMINAL VESICLES and the PROSTATE. They include the seminal vesicle-specific antigen, an ejaculate clotting protein; and the PROSTATE-SPECIFIC ANTIGEN, a protease and an esterase.

Seminal Vesicle Clotting Proteins [M0152027]

Seminal Vesicle Secretory Proteins [M0385043]
The secretory proteins of the seminal vesicles are proteins and enzymes that are important in the rapid clotting of the ejaculate. The major clotting protein is seminal vesicle-specific antigen. Many of these seminal vesicle proteins are under androgen regulation, and are substrates for the prostatic enzymes, such as the PROSTATE-SPECIFIC ANTIGEN, a protease and an esterase.

Semisynthetic Vaccines [M0022457]

Sendai Virus Fusion Protein [M0022728]

Sensory Rhodopsins [M0375051]
Photosensory rhodopsins found in microorganisms such as HALOBACTERIA. They convert light signals into biochemical information that regulates certain cellular functions such as flagellar motor activity.

Sericin-1 [M0053773]

Sericins [M0053774]
A serine-rich sticky protein secreted by MOTHS. Generally, the term refers to silkworm silk gum protein secreted in the middle section of silk gland cells of SILKWORMS, Bombyx mori. Sericin acts as a cement and coating for the two fibroin filaments in a silk strand and is readily soluble in mild alkaline solution.

Serine [M0019675]
A non-essential amino acid occurring in natural form as the L-isomer. It is synthesized from GLYCINE or THREONINE. It is involved in the biosynthesis of PURINES; PYRIMIDINES; and other amino acids.

Serine C-Palmitoyltransferase [M0119849]
A key enzyme in SPHINGOLIPIDS biosynthesis, this enzyme catalyzes the pyridoxal-5'-phosphate-dependent condensation of L-SERINE and PALMITOYL COENZYME A to 3-dehydro-D-sphinganine. The enzyme consists of two different subunits.

Serine Endopeptidases [M0019678]
Any member of the group of ENDOPEPTIDASES containing at the active site a serine residue involved in catalysis. EC 3.4.21.

Serine O-Acetyltransferase [M0078951]
An enzyme that catalyzes the conversion of L-SERINE to COENZYME A and O-acetyl-L-serine, using ACETYL-COA as a donor.

Serine-tRNA Ligase [M0019700]
An enzyme that activates serine with its specific transfer RNA. EC 6.1.1.11.

Serine-Type D-Ala-D-Ala Carboxypeptidase [M0455957]
A carboxypeptidase that is specific for proteins that contain two ALANINE residues on their C-terminal. Enzymes in this class play an important role in bacterial CELL WALL biosynthesis.

Sermorelin [M0026330]
The biologically active fragment of human growth hormone-releasing factor, consisting of GHRH(1-29)-amide. This N-terminal sequence is identical in several mammalian species, such as human, pig, and cattle. It is used to diagnose or treat patients with GROWTH HORMONE deficiency.

Sermorelin Acetate [M0026331]

Seromycin [M0372338]

Serotonectin [M0117243]
A sodium chloride-dependent neurotransmitter symporter located on the PLASMA MEMBRANE of BLOOD PLATELETS. It transports SEROTONIN from the EXTRACELLULAR SPACE into the platelet CYTOPLASM.

Serotonin Plasma Membrane Transport Proteins [M0475614]
Sodium chloride-dependent neurotransmitter symporters located primarily on the PLASMA MEMBRANE of serotonergic neurons. They are different than SEROTONIN RECEPTORS, which signal cellular responses to SEROTONIN. They remove SEROTONIN from the EXTRACELLULAR SPACE by high affinity reuptake into PRESYNAPTIC TERMINALS. Regulates signal amplitude and duration at serotonergic synapses and is the site of action of the SEROTONIN UPTAKE INHIBITORS.

Serotransferrin [M0021807]

Serpin Superfamily [M0024261]

Serpins [M0024262]
A family of serine proteinase inhibitors which are similar in amino acid sequence and mechanism of inhibition, but differ in their specificity toward proteolytic enzymes. This family includes alpha 1-antitrypsin, angiotensinogen, ovalbumin, antiplasmin, alpha 1-antichymotrypsin, thyroxine-binding protein, complement 1 inactivators, antithrombin III, heparin cofactor II, plasminogen inactivators, gene Y protein, placental plasminogen activator inhibitor, and barley Z protein. Some members of the serpin family may be substrates rather than inhibitors of SERINE ENDOPEPTIDASES, and some serpins occur in plants where their function is not known.

Serum Albumin [M0019692]
A major protein in the BLOOD. It is important in maintaining the colloidal osmotic pressure and transporting large organic molecules.

Serum Albumin, Bovine [M0019693]
Serum albumin from cows, commonly used in in vitro biological studies. (From Stedman, 25th ed)

Serum Albumin, Radio-Iodinated [M0019695]
Normal human serum albumin mildly iodinated with radioactive iodine (131-I) which has a half-life of 8 days, and emits beta and gamma rays. It is used as a diagnostic aid in blood volume determination. (from Merck Index, 11th ed)

Serum Amyloid A Protein [M0001052]
An ACUTE PHASE REACTION protein present in low concentrations in normal sera, but found at higher concentrations in sera of older persons and in patients with AMYLOIDOSIS. It is the circulating precusor of amyloid A protein, which is found deposited in AA type AMYLOID FIBRILS.

Serum Amyloid P-Component [M0001048]
Amyloid P component is a small, non-fibrillar glycoprotein found in normal serum and in all amyloid deposits. It has a pentagonal (pentaxin) structure. It is an acute phase protein, modulates immunologic responses, inhibits ELASTASE, and has been suggested as an indicator of LIVER DISEASE.

Serum Globulins [M0019698]
All blood proteins except albumin ( = SERUM ALBUMIN, which is not a globulin) and FIBRINOGEN (which is not in the serum). The serum globulins are subdivided into ALPHA-GLOBULINS; BETA-GLOBULINS; and GAMMA-GLOBULINS on the basis of their electrophoretic mobilities. (From Dorland, 28th ed)

Serum Proteins [M0002713]

Serum Response Factor [M0160475]
A MADS domain-containing transcription factor that binds to the SERUM RESPONSE ELEMENT in the promoter-enhancer region of many genes. It is one of the four founder proteins that structurally define the superfamily of MADS DOMAIN PROTEINS.

Serum-Response-Factor Protein-1a [M0197460]

Serum-Response-Factor Protein-1b [M0197462]

Sethotope [M0352159]

Sex Hormone-Binding Globulin [M0019743]
A glycoprotein migrating as a beta-globulin. Its molecular weight, 52,000 or 95,000-115,000, indicates that it exists as a dimer. The protein binds testosterone, dihydrotestosterone, and estradiol in the plasma. Sex hormone-binding protein has the same amino acid sequence as ANDROGEN-BINDING PROTEIN. They differ by their sites of synthesis and post-translational oligosaccharide modifications.

Sex Pili Structural Proteins [M0411012]

Sex-Determining Region Y Protein [M0179007]
A high mobility group protein encoded by the Y CHROMOSOME. It functions as a transcription factor and is essential for development of the TESTES.

SGOT [M0001825]

SGPT [M0000621]

SH Protease [M0005546]

Shab Potassium Channels [M0481409]
A subfamily of shaker potassium channels that shares homology with its founding member, Shab protein, Drosophila. They regulate delayed rectifier currents in the NERVOUS SYSTEM of DROSOPHILA and in the SKELETAL MUSCLE and HEART of VERTEBRATES.

Shaker Potassium Channels [M0483508]

Shaker Superfamily of Potassium Channels [M0481266]
Voltage-gated potassium channels whose primary subunits contain six transmembrane segments and form tetramers to create a pore with a voltage sensor. They are related to their founding member, shaker protein, Drosophila.

Shal Potassium Channels [M0176530]
A shaker subfamily of potassium channels that participate in transient outward potassium currents by activating at subthreshold MEMBRANE POTENTIALS, inactivating rapidly, and recovering from inactivation quickly.

Shaw Potassium Channels [M0264045]
A shaker subfamily that is prominently expressed in NEURONS and are necessary for high-frequency, repetitive firing of ACTION POTENTIALS.

SHP1 Protein Tyrosine Phosphatase [M0214713]
A Src-homology domain-containing protein tyrosine phosphatase found in the CYTOSOL of hematopoietic cells. It plays a role in signal transduction by dephosphorylating signaling proteins that are activated or inactivated by PROTEIN-TYROSINE KINASES.

Sialoglycopeptides [M0019814]

Sialoglycoproteins [M0019815]
Glycoproteins which contain sialic acid as one of their carbohydrates. They are often found on or in the cell or tissue membranes and participate in a variety of biological activities.

Sialomucins [M0058741]
A subcategory of mucins that contain SIALIC ACID.

Sialoproteins [M0019816]

Sialyl Apo C-III [M0073734]

Sialyl SSEA-1 [M0024833]

Sialyltransferases [M0019822]
A group of enzymes with the general formula CMP-N-acetylneuraminate:acceptor N-acetylneuraminyl transferase. They catalyze the transfer of N-acetylneuraminic acid from CMP-N-acetylneuraminic acid to an acceptor, which is usually the terminal sugar residue of an oligosaccharide, a glycoprotein, or a glycolipid. EC 2.4.99.-.

Siccoral [M0444759]

Sigma Factor [M0019833]
A protein which is a subunit of RNA polymerase. It effects initiation of specific RNA chains from DNA.

Sigma Factor 54 [M0483894]
A DNA-binding protein from BACTERIA that is a subunit of RNA POLYMERASE SIGMA 54. It is required for PROMOTER recognition and initiation of GENETIC TRANSCRIPTION.

Signal Peptide p25-Subunit IV Cytochrome Oxidase [M0005588]

Signal Recognition Particle [M0027499]
A cytosolic ribonucleoprotein complex that acts to induce elongation arrest of nascent presecretory and membrane proteins until the ribosome becomes associated with the rough endoplasmic reticulum. It consists of a 7S RNA and at least six polypeptide subunits (relative molecular masses 9, 14, 19, 54, 68, and 72K).

Silent Information Regulator Proteins, Saccharomyces cerevisiae [M0415710]
A set of nuclear proteins in SACCHAROMYCES CEREVISIAE that are required for the transcriptional repression of the silent mating type loci. They mediate the formation of silenced CHROMATIN and repress both transcription and recombination at other loci as well. They are comprised of 4 non-homologous, interacting proteins, Sir1p, Sir2p, Sir3p, and Sir4p. Sir2p, an NAD-dependent HISTONE DEACETYLASE, is the founding member of the family of SIRTUINS.

Silent Mating Type Information Regulator Protein, S cerevisiae [M0415711]

Silk [M0053814]
A continuous protein fiber consisting primarily of FIBROINS. It is synthesized by a variety of INSECTS and ARACHNIDS.

Silver Plastocyanin [M0017006]

Silver Proteinate [M0019871]

Silver Proteins [M0019870]
Compounds of silver and proteins used as topical anti-infective agents.

Simian Sarcoma Virus Glycoprotein 70 [M0022714]

Simian Sarcoma Virus Proteins [M0001441]

Simian Virus 40 Virion Protein 1 [M0024033]

Sincalide [M0019891]
An octapeptide hormone present in the intestine and brain. When secreted from the gastric mucosa, it stimulates the release of bile from the gallbladder and digestive enzymes from the pancreas.

Single-Chain Urokinase-Type Plasminogen Activator [M0022398]

Single-Stranded DNA Binding Proteins [M0006679]

Single-Stranded Telomere-Binding Proteins [M0194757]

Sirohaem Sulfite Reductase [M0283299]

Sirtuins [M0413549]
A homologous family of proteins that includes the NAD-dependent protein deacetylases which deacetylate proteins by catalyzing the formation of O-acetyl-ADP-ribose from the ADP-RIBOSE moiety (of NAD) and the acetyl group that is being removed from the protein. Sir2p, from Saccharomyces cerevisiae, is the founding member and the family includes other homologs (HSTs - homologs of Sir Two). Some HISTONE DEACETYLASES (the Sir2-like HDACs) belong to this family of proteins.

Site-Specific DNA Methyltransferase (Cytosine-Specific) [M0023497]
An enzyme responsible for producing a species-characteristic methylation pattern on cytosine residues in a specific short base sequence in the host cell's DNA. The enzyme catalyzes the methylation of DNA cytosine in the presence of S-adenosyl-L-methionine to form S-adenosyl-L-homocysteine and DNA containing 5-methylcytosine. EC 2.1.1.73.

Site-Specific DNA-Methyltransferase (Adenine-Specific) [M0023504]
An enzyme responsible for producing a species-characteristic methylation pattern on adenine residues in a specific short base sequence in the host cell DNA. The enzyme catalyzes the methylation of DNA adenine in the presence of S-adenosyl-L-methionine to form DNA containing 6-methylaminopurine and S-adenosyl-L-homocysteine. EC 2.1.1.72.

Skeletal Muscle Myosins [M0371733]
Myosin type II isoforms found in skeletal muscle.

Skin Tryptase [M0496667]

SKP Cullin F-Box Protein Ligases [M0446345]
A subset of ubiquitin protein ligases that are formed by the association of a SKP DOMAIN PROTEIN, a CULLIN DOMAIN PROTEIN and a F-BOX DOMAIN PROTEIN.

Skp1 Proteins [M0252305]

SKP1-Cullin Ubiquitin Ligases [M0302611]

Skp2 Proteins [M0446160]

Slow alpha 2-Macroglobulins [M0000772]

Smad Proteins [M0418709]
A family of proteins that are involved in the translocation of signals from TGF-BETA RECEPTORS; BONE MORPHOGENETIC PROTEIN RECEPTORS; and other surface receptors to the CELL NUCLEUS. They were originally identified as a class of proteins that are related to the mothers against decapentaplegic protein, Drosophila and sma proteins from CAENORHABDITIS ELEGANS.

Smad Proteins, Inhibitory [M0482097]
A sub-family of smad proteins that inhibit cell signaling by RECEPTOR-REGULATED SMAD PROTEINS. They form autoinhibitory feedback loops in the TGF-BETA signaling pathway and mediate signaling cross-talk with other signaling pathways

Smad Proteins, Receptor-Regulated [M0482096]
A family of smad proteins that undergo PHOSPHORYLATION by CELL SURFACE RECEPTORS in response to TRANSFORMING GROWTH FACTOR BETA; ACTIVIN; or BONE MORPHOGENETIC PROTEIN signaling.

Smad1 Protein [M0482098]
A receptor-regulated smad protein that undergoes PHOSPHORYLATION by BONE MORPHOGENETIC PROTEIN RECEPTORS. It regulates BONE MORPHOGENETIC PROTEIN signaling and plays an essential role in EMBRYONIC DEVELOPMENT.

Smad2 Protein [M0264868]
A receptor-regulated smad protein that undergoes PHOSPHORYLATION by ACTIVIN RECEPTORS, TYPE I. It regulates TRANSFORMING GROWTH FACTOR BETA and ACTIVIN signaling.

Smad3 Protein [M0265159]
A receptor-regulated smad protein that undergoes PHOSPHORYLATION by ACTIVIN RECEPTORS, TYPE I. Activated Smad3 can bind directly to DNA, and it regulates TRANSFORMING GROWTH FACTOR BETA and ACTIVIN signaling.

Smad4 Protein [M0482114]
A signal transducing adaptor protein and tumor suppressor protein. It forms a complex with activated RECEPTOR-REGULATED SMAD PROTEINS. The complex then translocates to the CELL NUCLEUS and regulates GENETIC TRANSCRIPTION of target GENES.

Smad5 Protein [M0265974]
A receptor-regulated smad protein that undergoes PHOSPHORYLATION by BONE MORPHOGENETIC PROTEIN RECEPTORS. It regulates BONE MORPHOGENETIC PROTEIN signaling and is essential for PHYSIOLOGICAL ANGIOGENESIS.

Smad6 Protein [M0278165]
An inhibitory Smad protein that negatively regulates the SIGNAL TRANSDUCTION PATHWAYS from BONE MORPHOGENETIC PROTEIN RECEPTORS. Smad6 inhibits PHOSPHORYLATION of SMAD2 PROTEIN and SMAD3 PROTEIN.

Smad7 Protein [M0280200]
An inhibitory smad protein that associates with TRANSFORMING GROWTH FACTOR BETA RECEPTORS and BONE MORPHOGENETIC PROTEIN RECEPTORS. It negatively regulates SIGNAL TRANSDUCTION PATHWAYS by inhibiting PHOSPHORYLATION of RECEPTOR-REGULATED SMAD PROTEINS.

Smad8 Protein [M0482123]
A receptor-regulated smad protein that undergoes PHOSPHORYLATION by BONE MORPHOGENETIC PROTEIN RECEPTORS and regulates BONE MORPHOGENETIC PROTEIN signaling.

Small Myelin-Associated Glycoprotein Isoform [M0028364]

Small Ubiquitin-Related Modifier Proteins [M0376142]
A class of structurally related proteins of 12-20 kDa in size. They covalently modify specific proteins in a manner analogous to UBIQUITIN.

Small-Conductance Calcium-Activated Potassium Channels [M0265387]
A major class of calcium-activated potassium channels that are found primarily in excitable CELLS. They play important roles in the transmission of ACTION POTENTIALS and generate a long-lasting hyperpolarization known as the slow afterhyperpolarization.

Smooth Muscle Myosin-bound Phosphatase [M0079050]

Smooth Muscle Myosins [M0371734]
Myosin type II isoforms found in smooth muscle.

Smooth Muscle Phosphatase-I [M0079051]

Smooth Muscle Phosphatase-II [M0079052]

SMS 201-995 [M0333645]

SNAP-25B Protein [M0171970]

SNARE Proteins [M0250560]
A superfamily of small proteins which are involved in the MEMBRANE FUSION events, intracellular protein trafficking and secretory processes. They share a homologous SNARE motif. The SNARE proteins are divided into subfamilies: QA-SNARES; QB-SNARES; QC-SNARES; and R-SNARES. The formation of a SNARE complex (composed of one each of the four different types SNARE domains (Qa, Qb, Qc, and R)) mediates MEMBRANE FUSION. Following membrane fusion SNARE complexes are dissociated by the NSFs (N-ETHYLMALEIMIDE-SENSITIVE FACTORS), in conjunction with SOLUBLE NSF ATTACHMENT PROTEIN, i.e., SNAPs (no relation to SNAP 25.)

Sodium Caseinate [M0003595]

Sodium Channels [M0023385]
Cell membrane glycoproteins selective for sodium ions. Fast sodium current is associated with the action potential in neural membranes.

Sodium Chloride Symporters [M0471876]
A subclass of symporters found in KIDNEY TUBULES, DISTAL that are the major pathway for salt resorption. Inhibition of these symporters by BENZOTHIADIAZINES is the basis of action of some DIURETICS.

Sodium Chloride-Dependent Neurotransmitter Symporters [M0476905]
A subclass of plasma membrane neurotransmitter transport proteins that co-transports NEUROTRANSMITTERS with SODIUM CHLORIDE.

Sodium Dependent Neutral Amino Acid Transporters [M0379270]

Sodium Glutamate [M0020104]
One of the FLAVORING AGENTS used to impart a meat-like flavor. Medically it has been used to reduce blood ammonia levels in ammoniacal azotemia, therapy of hepatic coma, in psychosis, and mental retardation.

Sodium Independent Neutral Amino Acid Transporters [M0151517]

Sodium Insulin [M0011421]

Sodium Sarcosinate [M0019446]

Sodium-Bicarbonate Symporters [M0140377]
Proteins that cotransport sodium ions and bicarbonate ions across cellular membranes.

Sodium-Calcium Exchanger [M0029431]
An electrogenic ion exchange protein that maintains a steady level of calcium by removing an amount of calcium equal to that which enters the cells. It is widely distributed in most excitable membranes, including the brain and heart.

Sodium-Glucose Transport Proteins [M0014036]
Monosaccharide transport proteins that function as active symporters. They utilize SODIUM or HYDROGEN IONS to transport GLUCOSE across CELL MEMBRANES.

Sodium-Glucose Transporter 1 [M0223862]
The founding member of the sodium glucose transport proteins. It is predominately expressed in the INTESTINAL MUCOSA of the SMALL INTESTINE.

Sodium-Glucose Transporter 2 [M0480065]
A sodium-glucose transporter that is expressed in the luminal membrane of the PROXIMAL KIDNEY TUBULES.

Sodium-Glutamate Cotransporter [M0477121]

Sodium-Hydrogen Antiporter [M0027078]
A plasma membrane exchange glycoprotein transporter that functions in intracellular pH regulation, cell volume regulation, and cellular response to many different hormones and mitogens.

Sodium-Phosphate Cotransporter Proteins [M0146276]
A family of symporters that facilitate sodium-dependent membrane transport of phosphate.

Sodium-Phosphate Cotransporter Proteins, Type I [M0476703]
A family of sodium-phosphate cotransporter proteins that also transport organic ANIONS. They are low affinity phosphate transporters.

Sodium-Phosphate Cotransporter Proteins, Type II [M0476701]
A family of sodium-phosphate cotransporter proteins with eight transmembrane domains. They are present primarily in the KIDNEY and SMALL INTESTINE and are responsible for renal and small intestinal epithelial transport of phosphate.

Sodium-Phosphate Cotransporter Proteins, Type IIa [M0476828]
An electrogenic sodium-dependent phosphate transporter. It is present primarily in BRUSH BORDER membranes of PROXIMAL RENAL TUBULES.

Sodium-Phosphate Cotransporter Proteins, Type IIb [M0476829]
A sodium-dependent phosphate transporter present primarily at apical sites of EPITHELIAL CELLS in the SMALL INTESTINE.

Sodium-Phosphate Cotransporter Proteins, Type IIc [M0476830]
A non-electrogenic sodium-dependent phosphate transporter. It is found primarily in apical membranes of PROXIMAL RENAL TUBULES.

Sodium-Phosphate Cotransporter Proteins, Type III [M0371702]
A family of highly conserved and widely expressed sodium-phosphate cotransporter proteins. They are electrogenic sodium-dependent transporters of phosphate that were originally identified as retroviral receptors in HUMANS and have been described in yeast and many other organisms.

Sodium-Potassium-Chloride Symporters [M0125395]
A subclass of symporters that specifically transport SODIUM CHLORIDE and POTASSIUM CHLORIDE across cellular membranes in a tightly coupled process.

Sodium-Sugar Transporter [M0014042]

Solmucol [M0444758]

Soluble N-Ethylmaleimide-Sensitive Factor Attachment Proteins [M0202550]
SNARE binding proteins that facilitate the ATP hydrolysis-driven dissociation of the SNARE complex. They are required for the binding of N-ETHYLMALEIMIDE-SENSITIVE PROTEIN (NSF) to the SNARE complex which also stimulates the ATPASE activity of NSF. They are unrelated structurally to SNAP-25 PROTEIN.

Somatofalk [M0020153]

Somatomedins [M0020150]
Insulin-like polypeptides made by the liver and some fibroblasts and released into the blood when stimulated by SOMATOTROPIN. They cause sulfate incorporation into collagen, RNA, and DNA synthesis, which are prerequisites to cell division and growth of the organism.

Somatostatin [M0020152]
A 14-amino acid peptide named for its ability to inhibit pituitary GROWTH HORMONE release, also called somatotropin release-inhibiting factor. It is expressed in the central and peripheral nervous systems, the gut, and other organs. SRIF can also inhibit the release of THYROID-STIMULATING HORMONE; PROLACTIN; INSULIN; and GLUCAGON besides acting as a neurotransmitter and neuromodulator. In a number of species including humans, there is an additional form of somatostatin, SRIF-28 with a 14-amino acid extension at the N-terminal.

Somatostatin-28 [M0087146]
A 28-amino acid peptide with the same biological activities of somatostatin-14 but with a 14-amino acid extension at the N-terminal. SRIF-28 is the major form of somatostatin in the GASTROINTESTINAL TRACT.

Son of Sevenless Protein, Drosophila [M0328290]
A guanine nucleotide exchange factor from DROSOPHILA. Sevenless refers to genetic mutations in DROSOPHILA that cause loss of the R7 photoreceptor which is required to see UV light.

Son of Sevenless Proteins [M0328293]
A class of RAS GUANINE NUCLEOTIDE EXCHANGE FACTORS that are genetically related to the Son of Sevenless gene from DROSOPHILA. Sevenless refers to genetic mutations in DROSOPHILA that cause loss of the R7 photoreceptor which is required to see UV light.

Sonic Hedgehog Protein [M0235918]

SOS1 Protein [M0328297]
A mammalian homolog of the DROSOPHILA SON OF SEVENLESS PROTEIN. It is a guanine nucleotide exchange factor for RAS PROTEINS.

Soybean Proteins [M0386765]
Proteins which are present in or isolated from SOYBEANS.

Sp Transcription Factors [M0481539]
A family of DNA-binding proteins that contain three ZINC FINGERS at their carboxy termini. They are transcription factors that have specificity for GC boxes.

Sp1 Transcription Factor [M0024957]
Promoter-specific RNA polymerase II transcription factor that binds to the GC box, one of the upstream PROMOTER elements, in mammalian cells. The binding of Sp1 is necessary for the initiation of transcription in the promoters of a variety of cellular and viral GENES.

Sp2 Transcription Factor [M0206586]
A ubiquitously expressed Sp transcription factor that binds to the consensus DNA sequence GGGCGGGAC.

Sp3 Transcription Factor [M0206592]
A specificity protein transcription factor that regulates expression of a variety of genes including VASCULAR ENDOTHELIAL GROWTH FACTOR and CYCLIN-DEPENDENT KINASE INHIBITOR P27.

Sp4 Transcription Factor [M0262068]
A specificity protein transcription factor that is expressed primarily in the CENTRAL NERVOUS SYSTEM.

Spectrin [M0020228]
A high molecular weight (220-250 kDa) water-soluble protein which can be extracted from erythrocyte ghosts in low ionic strength buffers. The protein contains no lipids or carbohydrates, is the predominant species of peripheral erythrocyte membrane proteins, and exists as a fibrous coating on the inner, cytoplasmic surface of the membrane.

Spermidine Synthase [M0017780]
An enzyme that catalyzes the transfer of the propylamine moiety from 5'-deoxy-5'-S-(3-methylthiopropylamine)sulfonium adenosine to putrescine in the biosynthesis of spermidine. The enzyme has a molecular weight of approximately 73,000 kDa and is composed of two subunits of equal size.

Spermine Synthase [M0020289]
An enzyme that catalyzes the transfer of the propylamine moiety from 5'-deoxy-5'-S-(3-methylthiopropylamine)sulfonium adenosine to spermidine in the biosynthesis of spermine. It has an acidic isoelectric point at pH 5.0. EC 2.5.1.22.

Sphingolipid Activator Proteins [M0463628]
A family of glycoprotein cofactors that are required for the efficient catabolization of SPHINGOLIPIDS by specific acid hydrolases such as GLUCOSYLCERAMIDASE; GALACTOCEREBROSIDASE; BETA-N-ACETYLHEXOSAMINIDASE; and CEREBROSIDE-SULFATASE.

Sphingomyelin Phosphodiesterase [M0020300]
An enzyme that catalyzes the hydrolysis of sphingomyelin to ceramide (N-acylsphingosine) plus choline phosphate. A defect in this enzyme leads to NIEMANN-PICK DISEASE. EC 3.1.4.12.

Sphingosine N-Acyltransferase [M0134312]
An enzyme that catalyzes the acyltransferase of SPHINGOSINE to N-acylsphingosine using acyl-COENZYME A as donor and COENZYME A as acceptor. The enzyme is mainly localized in the MITOCHONDRIA.

Sphingosine Phosphorylcholine Receptors [M0464262]

Sphingosine-1-Phosphate Receptors [M0262120]

Splice Variants, Protein [M0495713]

Spongostan [M0008429]

SQ-14,225 [M0338110]

SQ-14,534 [M0003320]

SQ-19,844 [M0373217]

SQ-20881 [M0373891]

SQ-28,555 [M0352131]

Squalene Monooxygenase [M0079002]
The second enzyme in the committed pathway for CHOLESTEROL biosynthesis, this enzyme catalyzes the first oxygenation step in the biosynthesis of STEROLS and is thought to be a rate limiting enzyme in this pathway. Specifically, this enzyme catalyzes the conversion of SQUALENE to (S)-squalene-2,3-epoxide.

src-Family Kinases [M0028454]
A PROTEIN-TYROSINE KINASE family that was originally identified by homology to the Rous sarcoma virus ONCOGENE PROTEIN PP60(V-SRC). They interact with a variety of cell-surface receptors and participate in intracellular signal transduction pathways. Oncogenic forms of src-family kinases can occur through altered regulation or expression of the endogenous protein and by virally encoded src (v-src) genes.

SRS-A Receptors [M0027270]

Ss Erythrocyte Membrane Sialoglycoproteins [M0009489]

Staphylocoagulase [M0004657]
An extracellular protein which specifically forms a complex with human prothrombin. This complex named staphylothrombin can clot fibrinogen without any proteolytic cleavage of prothrombin.

Staphylococcal Clumping Factor [M0004655]

Staphylococcal Protein A [M0020425]
A protein present in the cell wall of most Staphylococcus aureus strains. The protein selectively binds to the Fc region of human normal and myeloma-derived IMMUNOGLOBULIN G. It elicits antibody activity and may cause hypersensitivity reactions due to histamine release; has also been used as cell surface antigen marker and in the clinical assessment of B lymphocyte function.

Staphylococcus aureus clone pSCa2 of Coagulase [M0331203]

Staphylococcus aureus strain 213 of Coagulase [M0331204]

Staphylococcus aureus strain 8325-4 of Coagulase [M0331205]

Staphylomycin [M0375365]

Starch Phosphorylase [M0332560]
An enzyme of the PHOSPHORYLASES family that catalyzes the degradation of starch, a mixture of unbranched AMYLOSE and branched AMYLOPECTIN compounds. This phosphorylase from plants is the counterpart of GLYCOGEN PHOSPHORYLASE in animals that catalyzes the reaction of inorganic phosphate on the terminal alpha-1,4-glycosidic bond at the non-reducing end of glucans resulting in the release of glucose-1-phosphate.

Starch Phosphorylase a [M0378550]

Starch Phosphorylase b [M0378551]

Starch Synthase [M0020437]
An enzyme that catalyzes the transfer of glucose from ADPglucose to glucose-containing polysaccharides in 1,4-alpha-linkages. EC 2.4.1.21.

STAT Transcription Factors [M0477894]
A family of transcription factors containing SH2 DOMAINS that are involved in CYTOKINE-mediated SIGNAL TRANSDUCTION. STAT transcription factors are recruited to the cytoplasmic region of CELL SURFACE RECEPTORS and are activated via PHOSPHORYLATION. Once activated they dimerize and translocate into the CELL NUCLEUS where they influence GENE expression. They play a role in regulating CELL GROWTH PROCESSES and CELL DIFFERENTIATION. STAT transcription factors are inhibited by SUPPRESSOR OF CYTOKINE SIGNALING PROTEINS and PROTEIN INHIBITORS OF ACTIVATED STAT.

STAT1 Transcription Factor [M0211005]
A signal transducer and activator of transcription that mediates cellular responses to INTERFERONS. Stat1 interacts with P53 TUMOR SUPPRESSOR PROTEIN and regulates expression of GENES involved in growth control and APOPTOSIS.

STAT2 Transcription Factor [M0244035]
A signal transducer and activator of transcription that mediates cellular responses to TYPE I INTERFERONS. Stat2 protein is associated constitutively with INTERFERON REGULATORY FACTOR-9. After PHOSPHORYLATION Stat2 forms the IFN-STIMULATED GENE FACTOR 3 COMPLEX to regulate expression of target GENES.

STAT3 Transcription Factor [M0229085]
A signal transducer and activator of transcription that mediates cellular responses to INTERLEUKIN-6 family members. STAT3 is constitutively activated in a variety of TUMORS and is a major downstream transducer for the CYTOKINE RECEPTOR GP130.

STAT3a Transcription Factor [M0229080]

STAT3b Transcription Factor [M0229081]

STAT4 Transcription Factor [M0231457]
A signal transducer and activator of transcription that mediates cellular responses to INTERLEUKIN-12 in T-LYMPHOCYTES. Stat4 is an important signaling molecule for differentiation in TH1 CELLS.

STAT4A Transcription Factor [M0454396]

STAT4b Transcription Factor [M0454397]

STAT5 Transcription Factor [M0420149]
A signal transducer and activator of transcription that mediates cellular responses to a variety of CYTOKINES. Stat5 activation is associated with transcription of CELL CYCLE regulators such as CYCLIN KINASE INHIBITOR P21 and anti-apoptotic genes such as BCL-2 GENES. Stat5 is constitutively activated in many patients with acute MYELOID LEUKEMIA.

STAT5a Transcription Factor [M0204508]

STAT5b Transcription Factor [M0204507]

STAT6 Transcription Factor [M0247161]
A signal transducer and activator of transcription that mediates cellular responses to INTERLEUKIN-4. Stat6 has been shown to partner with NF-KAPPA B and CCAAT-ENHANCER-BINDING PROTEINS to regulate GENETIC TRANSCRIPTION of interleukin-4 responsive GENES.

Stathmin [M0166763]
A ubiquitous phosphoprotein that serves as an intracellular substrate for a variety of SIGNAL TRANSDUCTION PATHWAYS. PHOSPHORYLATION of stathmin occurs during CELL CYCLE progression, and stathmin functions as a microtubule-destabilizing protein that promotes MICROTUBULE depolymerization during INTERPHASE and late MITOSIS. Stathmin is expressed at very high levels in a variety of human CANCERS.

Stearoyl-CoA Desaturase [M0020468]
An enzyme that catalyzes the formation of oleoyl-CoA, A, and water from stearoyl-CoA, AH2, and oxygen where AH2 is an unspecified hydrogen donor. EC 1.14.99.5.

Stem Cell Factor [M0028491]
A hematopoietic growth factor and the ligand of the cell surface c-kit protein (PROTO-ONCOGENE PROTEINS C-KIT). It is expressed during embryogenesis and is a growth factor for a number of cell types including the MAST CELLS and the MELANOCYTES in addition to the HEMATOPOIETIC STEM CELLS.

Sterigmatocystin Polyketide Synthase [M0171391]

Steroid 11-beta-Hydroxylase [M0020521]
A mitochondrial cytochrome P450 enzyme that catalyzes the 11-beta-hydroxylation of steroids in the presence of molecular oxygen and NADPH-FERRIHEMOPROTEIN REDUCTASE. This enzyme, encoded by CYP11B1 gene, is important in the synthesis of CORTICOSTERONE and HYDROCORTISONE. Defects in CYP11B1 cause congenital adrenal hyperplasia (ADRENAL HYPERPLASIA, CONGENITAL).

Steroid 12-alpha-Hydroxylase [M0020522]
A liver microsomal cytochrome P450 enzyme that catalyzes the 12-alpha-hydroxylation of a broad spectrum of sterols in the presence of molecular oxygen and NADPH-FERRIHEMOPROTEIN REDUCTASE. This enzyme, encoded by CYP8B1gene, converts 7-alpha-hydroxy-4-cholesten-3-one to 7-alpha-12-alpha-dihydroxy-4-cholesten-3-one and is required in the synthesis of BILE ACIDS from cholesterol.

Steroid 16-alpha-Hydroxylase [M0418489]
A liver microsomal cytochrome P450 enzyme that catalyzes the 16-alpha-hydroxylation of a broad spectrum of steroids, fatty acids, and xenobiotics in the presence of molecular oxygen and NADPH-FERRIHEMOPROTEIN REDUCTASE. This enzyme is encoded by a number of genes from several CYP2 subfamilies.

Steroid 17-alpha-Hydroxylase [M0020523]
A microsomal cytochrome P450 enzyme that catalyzes the 17-alpha-hydroxylation of progesterone or pregnenolone and subsequent cleavage of the residual two carbons at C17 in the presence of molecular oxygen and NADPH-FERRIHEMOPROTEIN REDUCTASE. This enzyme, encoded by CYP17 gene, generates precursors for glucocorticoid, androgen, and estrogen synthesis. Defects in CYP17 gene cause congenital adrenal hyperplasia (ADRENAL HYPERPLASIA, CONGENITAL) and abnormal sexual differentiation.

Steroid 21-Hydroxylase [M0020524]
An adrenal microsomal cytochrome P450 enzyme that catalyzes the 21-hydroxylation of steroids in the presence of molecular oxygen and NADPH-FERRIHEMOPROTEIN REDUCTASE. This enzyme, encoded by CYP21 gene, converts progesterones to precursors of adrenal steroid hormones (CORTICOSTERONE; HYDROCORTISONE). Defects in CYP21 cause congenital adrenal hyperplasia (ADRENAL HYPERPLASIA, CONGENITAL).

Steroid Hydroxylases [M0020519]
Cytochrome P-450 monooxygenases (MIXED FUNCTION OXYGENASES) that are important in steroid biosynthesis and metabolism.

Steroid Isomerases [M0020520]
Enzymes that catalyze the transposition of double bond(s) in a steroid molecule. EC 5.3.3.

Sterol O-Acyltransferase [M0004270]
An enzyme that catalyzes the formation of cholesterol esters by the direct transfer of the fatty acid group from a fatty acyl CoA derivative. This enzyme has been found in the adrenal gland, gonads, liver, intestinal mucosa, and aorta of many mammalian species. EC 2.3.1.26.

Sterol Regulatory Element Binding Protein 1 [M0218287]
A sterol regulatory element binding protein that regulates expression of GENES involved in FATTY ACIDS metabolism and LIPOGENESIS. Two major isoforms of the protein exist due to ALTERNATIVE SPLICING.

Sterol Regulatory Element Binding Protein 1a [M0218284]
SREBP1-A is an isoform of sterol regulatory element binding protein 1 that is a potent activator of GENETIC TRANSCRIPTION. It is the predominant form in SPLEEN.

Sterol Regulatory Element Binding Protein 1c [M0350711]
SREBP1-C is an isoform of sterol regulatory element binding protein 1 that is a weak activator of GENETIC TRANSCRIPTION. It is the predominant form in LIVER and ADIPOCYTES, and it mediates INSULIN induced FATTY ACID synthesis.

Sterol Regulatory Element Binding Protein 2 [M0225522]
A sterol regulatory element binding protein that regulates GENES involved in CHOLESTEROL synthesis and uptake.

Sterol Regulatory Element Binding Proteins [M0481799]
Sterol regulatory element binding proteins are basic helix-loop-helix leucine zipper transcription factors that bind the sterol regulatory element TCACNCCAC. They are synthesized as precursors that are threaded into the MEMBRANES of the ENDOPLASMIC RETICULUM.

Steryl-Sulfatase [M0072540]
An arylsulfatase with high specificity towards sulfated steroids. Defects in this enzyme are the cause of ICHTHYOSIS, X-LINKED.

Stilamin [M0020154]

Stimate [M0492525]

Streptase [M0020582]

Streptavidin [M0029402]
A 60-kDa extracellular protein of Streptomyces avidinii with four high-affinity biotin binding sites. Unlike AVIDIN, streptavidin has a near neutral isoelectric point and is free of carbohydrate side chains.

Streptodecase [M0020588]

Streptodornase [M0006008]

Streptodornase and Streptokinase [M0020578]
A mixture of the enzymes (streptokinase and streptodornase) produced by hemolytic streptococci. It is used topically on surface lesions and by instillation in closed body cavities to remove clotted blood or fibrinous or purulent accumulations. It is also used as a skin test antigen in evaluating generalized cell-mediated immunodeficiency. (Dorland, 27th ed) EC 3.-.

Streptogramin A [M0374398]
A specific streptogramin group A antibiotic produced by Streptomyces graminofaciens and other bacteria.

Streptogramin B [M0374395]
A specific streptogramin group B antibiotic produced by Streptomyces graminofaciens and other bacteria.

Streptogramin Group A [M0374393]
A structural subclass of streptogramins that includes molecules containing unsaturated macrocyclic lactones with approximate molecular weight of 500 KDa.

Streptogramin Group B [M0374412]
A structural subclass of streptogramins. They are cyclic hexadepsipeptides with approximate molecular weight of 800 that contain a characteristic 3-hydroxy picolinoyl exocyclic component.

Streptogramins [M0022748]
A class of natural cyclic peptide antibiotics produced by certain subspecies of STREPTOMYCES. They include two structurally unrelated components, STREPTOGRAMIN GROUP A and STREPTOGRAMIN GROUP B, which generally act synergistically to inhibit bacterial growth.

Streptokinase [M0020580]
Streptococcal fibrinolysin . An enzyme produced by hemolytic streptococci. It hydrolyzes amide linkages and serves as an activator of plasminogen. It is used in thrombolytic therapy and is used also in mixtures with streptodornase (STREPTODORNASE AND STREPTOKINASE). EC 3.4.-.

Streptothricins [M0020598]
A group of antibiotic aminoglycosides differing only in the number of repeating residues in the peptide side chain. They are produced by Streptomyces and Actinomyces and may have broad spectrum antimicrobial and some antiviral properties.

Stress Protein 34 [M0009987]

Stress Protein 71 [M0009988]

Styrene Epoxide Hydrolase [M0007612]

Substance P [M0020674]
An eleven-amino acid neurotransmitter that appears in both the central and peripheral nervous systems. It is involved in transmission of PAIN, causes rapid contractions of the gastrointestinal smooth muscle, and modulates inflammatory and immune responses.

Subtilisin [M0328357]
A serine endopeptidase isolated from Bacillus subtilis. It hydrolyzes proteins with broad specificity for peptide bonds, and a preference for a large uncharged residue in P1. It also hydrolyzes peptide amides. (From Enzyme Nomenclature, 1992) EC 3.4.21.62.

Subtilisin 72 [M0020693]

Subtilisin BPN' [M0020694]

Subtilisin Carlsberg [M0020689]

Subtilisin-Like Proprotein Convertases [M0449282]

Subtilisins [M0020698]
A family of SERINE ENDOPEPTIDASES isolated from Bacillus subtilis. EC 3.4.21.-

Succinate Cytochrome c Oxidoreductase [M0020702]
An electron transport chain complex that catalyzes the transfer of electrons from SUCCINATE to CYTOCHROME C. It includes ELECTRON TRANSPORT COMPLEX II and ELECTRON TRANSPORT COMPLEX III.

Succinate Dehydrogenase [M0020703]
A flavoprotein containing oxidoreductase that catalyzes the dehdyrogenation of SUCCINATE to FUMARATE. In most eukaryotic organisms this enzyme is a component of mitochondrial electron transport complex II.

Succinate-CoA Ligase (GDP-Forming) [M0020709]

Succinate-CoA Ligases [M0020708]
Enzymes that catalyze the first step leading to the oxidation of succinic acid by the reversible formation of succinyl-CoA from succinate and CoA with the concomitant cleavage of ATP to ADP (EC 6.2.1.5) or GTP to GDP (EC 6.2.1.4) and orthophosphate. Itaconate can act instead of succinate and ITP instead of GTP.EC 6.2.1.-.

Succinate-CoA Ligases (ADP-Forming) [M0020710]

Succinate-Semialdehyde Dehydrogenase [M0079133]
An enzyme that plays a role in the GLUTAMATE and butanoate metabolism pathways by catalyzing the oxidation of succinate semialdehyde to SUCCINATE using NAD+ as a coenzyme. Deficiency of this enzyme, causes 4-hydroxybutyricaciduria, a rare inborn error in the metabolism of the neurotransmitter 4-aminobutyric acid (GABA).

Succinate-Semialdehyde Dehydrogenase (NADP+) [M0079135]
An enzyme that catalyzes the oxidation of succinate semialdehyde to SUCCINIC ACID. It plays a role in the metabolism of GLUTAMATE; TYROSINE; and butanoate.

Succinyldiaminopimelate Transaminase [M0299775]
A PYRIDOXAL PHOSPHATE containing enzyme that catalyzes the transfer amino group from N-succinyl-L-2,6-diaminoheptanedioate to 2-OXOGLUTARATE in order to generate N-succinyl-2-L-amino-6-oxoheptanedioate and L-GLUTAMATE, respectively.

Sucraid [M0445459]

Sucrase [M0020719]

Sucrase-Isomaltase Complex [M0020721]
An enzyme complex found in the brush border membranes of the small intestine. It is believed to be an enzyme complex with different catalytic sites. Its absence is manifested by an inherited disease called sucrase-isomaltase deficiency.

Sugar Alcohol Dehydrogenases [M0020727]
Reversibly catalyzes the oxidation of a hydroxyl group of sugar alcohols to form a keto sugar, aldehyde or lactone. Any acceptor except molecular oxygen is permitted. Includes EC 1.1.1.; EC 1.1.2. and EC 1.1.99.

Sulfatases [M0020759]

Sulfate Adenylyltransferase [M0020760]
An enzyme that catalyzes the activation of sulfate ions by ATP to form adenosine-5'-phosphosulfate and pyrophosphate. This reaction constitutes the first enzymatic step in sulfate utilization following the uptake of sulfate. EC 2.7.7.4.

Sulfhemoglobin [M0020765]

Sulfite Dehydrogenase [M0090252]
An enzyme that catalyzes oxidation of sulfite to sulfate along with the reduction of FERROCYTOCHROME C to FERRICYTOCHROME C.

Sulfite Dehydrogenases [M0478388]

Sulfite Oxidase [M0020781]
A MOLYBDENUM requiring enzyme that catalyzes the terminal reaction in the oxidative degradation of SULFUR AMINO ACIDS with the formation of a sulfate. A deficiency of sulfite oxidase results in sulfocysteinuria.

Sulfite Reductase (Ferredoxin) [M0108156]
A FERREDOXIN-dependent oxidoreductase that is primarily found in PLANTS where it plays an important role in the assimilation of SULFUR atoms for the production of CYSTEINE and METHIONINE.

Sulfite Reductase (NADPH) [M0113137]
A NADPH-dependent oxidase that reduces hydrogen sulfite to HYDROGEN SULFIDE. It is found in many microoganisms.

Sulfite Reductases [M0020783]

Sulfotransferases [M0023419]
Enzymes which transfer sulfate groups to various acceptor molecules. They are involved in posttranslational sulfation of proteins and sulfate conjugation of exogenous chemicals and bile acids. EC 2.8.2.

Sulfur Group Transferases [M0029526]
Enzymes that catalyze the transfer of sulfur atoms (2.8.1), sulfur groups (2.8.2) or coenzyme A (2.8.3). EC 2.8.

Sulfur-Sulfur Bond Isomerases [M0029316]
Enzymes that catalyze the transposition of a sulfur-sulfur bond. EC 5.3.4.

Sulfurtransferases [M0020809]
Enzymes which transfer sulfur atoms to various acceptor molecules. EC 2.8.1.

SUMO-1 Protein [M0266272]
A 1.5-kDa small ubiquitin-related modifier protein that can covalently bind via an isopeptide link to a number of cellular proteins. It may play a role in intracellular protein transport and a number of other cellular processes.

Superantigens [M0027285]
Microbial antigens that have in common an extremely potent activating effect on T-cells that bear a specific variable region. Superantigens cross-link the variable region with class II MHC proteins regardless of the peptide binding in the T-cell receptor's pocket. The result is a transient expansion and subsequent death and anergy of the T-cells with the appropriate variable regions.

Superoxide Dismutase [M0020832]
An oxidoreductase that catalyzes the reaction between superoxide anions and hydrogen to yield molecular oxygen and hydrogen peroxide. The enzyme protects the cell against dangerous levels of superoxide. EC 1.15.1.1.

Suppressor Factor (SF4) [M0020844]

Suppressor Factors, Immunologic [M0020845]
Proteins, protein complexes, or glycoproteins secreted by suppressor T-cells that inhibit either subsequent T-cells, B-cells, or other immunologic phenomena. Some of these factors have both histocompatibility (I-J) and antigen-specific domains which may be linked by disulfide bridges. They can be elicited by haptens or other antigens and may be mass-produced by hybridomas or monoclones in the laboratory.

Suppressor of Cytokine Signaling Proteins [M0478075]
A family of structurally related proteins that are induced by CYTOKINES and negatively regulate cytokine-mediated SIGNAL TRANSDUCTION PATHWAYS. SOCS proteins contain a central SH2 DOMAIN and a C-terminal region of homology known as the SOCS box.

Symporters [M0381333]
Membrane transporters that co-transport two or more dissimilar molecules in the same direction across a membrane. Usually the transport of one ion or molecule is against its electrochemical gradient and is "powered" by the movement of another ion or molecule with its electrochemical gradient.

Synapsin I [M0025444]

Synapsin II [M0025445]

Synapsin III [M0025443]

Synapsins [M0025442]
A family of synaptic vesicle-associated proteins involved in the short-term regulation of NEUROTRANSMITTER release. Synapsin I, the predominant member of this family, links SYNAPTIC VESICLES to ACTIN FILAMENTS in the presynaptic nerve terminal. These interactions are modulated by the reversible PHOSPHORYLATION of synapsin I through various signal transduction pathways. The protein is also a substrate for cAMP- and CALCIUM-CALMODULIN DEPENDENT PROTEIN KINASES. It is believed that these functional properties are also shared by synapsin II.

Synaptic Receptors [M0027154]

Synaptophysin [M0025448]
A 38-kDa integral membrane glycoprotein of the presynaptic vesicles in neuron and neuroendocrine cells. It is expressed by a variety of normal and neoplastic neuroendocrine cells and is therefore used as an immunocytochemical marker for neuroendocrine differentiation in various tumors. In ALZHEIMER DISEASE and other dementing disorders, there is an important synapse loss due in part to a decrease of synaptophysin in the presynaptic vesicles.

Synaptophysin, Rat Clone pSR(2) Protein Moiety, Reduced [M0329409]

Synaptosomal-Associated Protein 25 [M0171973]
A ubiquitous target SNARE protein that interacts with SYNTAXIN and SYNAPTOBREVIN. It is a core component of the machinery for intracellular MEMBRANE FUSION. The sequence contains 2 SNARE domains, one is the prototype for the Qb-SNARES, and the other is the prototype for the Qc-SNARES.

Synaptotagmin I [M0183221]
A vesicular transport protein expressed predominately in NEURONS. Synaptotagmin helps regulate EXOCYTOSIS of SYNAPTIC VESICLES and appears to serve as a calcium sensor to trigger NEUROTRANSMITTER release. It also acts as a nerve cell receptor for certain BOTULINUM TOXINS.

Synaptotagmin II [M0190840]
A vesicular transport protein that was originally characterized as an inositol polyphosphate binding protein. Synaptotagmin II helps regulate EXOCYTOSIS of SYNAPTIC VESICLES and appears to serve as a calcium sensor to trigger NEUROTRANSMITTER release. It also acts as a nerve cell receptor for certain BOTULINUM TOXINS.

Synaptotagmin III [M0183222]

Synaptotagmin IV [M0183223]

Synaptotagmin IX [M0478305]

Synaptotagmin V [M0183224]

Synaptotagmin VI [M0351602]

Synaptotagmin VII [M0361151]

Synaptotagmin VIII [M0183225]

Synaptotagmin XI [M0361171]

Synaptotagmin XII [M0478325]

Synaptotagmin XIII [M0383156]

Synaptotagmin XIV [M0478319]

Synaptotagmin XV [M0478321]

Synaptotagmins [M0183227]
A family of vesicular transport proteins characterized by an N-terminal transmembrane region and two C-terminal calcium-binding domains.

Synarel [M0373294]

Syndecan-1 [M0490148]
A syndecan that interacts with EXTRACELLULAR MATRIX PROTEINS and plays a role CELL PROLIFERATION and CELL MIGRATION.

Syndecan-2 [M0208527]
A syndecan that is predominantly expressed during EMBRYONIC DEVELOPMENT. It may play a role in mediating cellular interactions with the EXTRACELLULAR MATRIX and may modulate the signaling activity of certain INTERCELLULAR SIGNALING PEPTIDES AND PROTEINS.

Syndecan-3 [M0200064]
A syndecan found at high levels in the developing LIMB BUD. It may play a role in the regulation of MUSCULOSKELETAL DEVELOPMENT by modulating the effects of INTERCELLULAR SIGNALING PROTEINS AND PEPTIDES.

Syndecan-4 [M0226175]
A ubiquitously expressed syndecan that is found in all stages of embryonic development and in most adult tissues. Syndecan-4 is found localized to focal adhesion sites in fibronectin-adherent cells and may play a role the process of CELL MIGRATION and CELL PROLIFERATION.

Syndecans [M0164318]
A family of transmembrane glycoproteins that contain a short cytoplasmic domain, a single-span transmembrane domain, and an extracellular domain with HEPARIN SULFATE and CHONDROITIN SULFATE chains. Syndecans interact with a variety of heparin-binding INTERCELLULAR SIGNALING PROTEINS AND PEPTIDES and may play a role in modulating cellular signaling in during EMBRYONIC DEVELOPMENT, tumorigenesis, and angiogenesis.

Syntaxin 1 [M0201585]
A neuronal cell membrane protein that combines with SNAP-25 and SYNAPTOBREVIN 2 to form a SNARE complex that leads to EXOCYTOSIS.

Syntaxin 10 [M0478981]

Syntaxin 11 [M0478980]

Syntaxin 13 [M0478979]

Syntaxin 16 [M0286755]
A ubiquitously expressed member of the syntaxin subfamily of SNARE proteins that localizes to the GOLGI APPARATUS.

Syntaxin 17 [M0478978]

Syntaxin 18 [M0478989]

Syntaxin 3 [M0478988]

Syntaxin 3A [M0478987]

Syntaxin 3B [M0478986]

Syntaxin 3C [M0478985]

Syntaxin 3D [M0478984]

Syntaxin 4 [M0478983]

Syntaxin 5 [M0478993]

Syntaxin 6 [M0478992]

Syntaxin 7 [M0478991]

Syntaxin 8 [M0478990]

Syntaxin A [M0201586]

Syntaxin-1A [M0201592]

Syntaxin-1B [M0201588]

Syntaxin-1C [M0201589]

Syntaxin-2 [M0201590]

Syntenin-1 [M0495551]

Syntenin-2 [M0495552]

Syntenins [M0495550]
Intracellular signaling adaptor proteins that play a role in the coupling of SYNDECANS to CYTOSKELETAL PROTEINS.

Synthase D [M0009464]

Synthase I [M0009465]

Synthetic Peptide Combinatorial Library [M0028552]

Synthetic Peptide Library [M0028553]

Synthroid [M0373452]

Synthrox [M0463516]

Syntocinon [M0015704]

Synucleins [M0159754]
A family of homologous proteins of low MOLECULAR WEIGHT that are predominately expressed in the BRAIN and that have been implicated in a variety of human diseases. They were originally isolated from CHOLINERGIC FIBERS of TORPEDO.

T Cell Transcription Factor 1 [M0473255]
A TCF transcription factor that was originally identified as a DNA-binding protein that interacts with the ENHANCERS of T-CELL RECEPTOR ALPHA GENES. It is a plays a role in T-LYMPHOCYTE development.

T-1384 [M0369472]

T-Box Domain Proteins [M0328076]
Proteins containing a region of conserved sequence, about 200 amino acids long, which encodes a particular sequence specific DNA binding domain (the T-box domain). These proteins are transcription factors that control developmental pathways. The prototype of this family is the mouse Brachyury (or T) gene product.

T-Cell Receptors alpha-Chain [M0025429]

T-Cell Receptors delta-Chain [M0025426]

T-Kininogen [M0012051]

T. cruzi PEPCK [M0029326]

T4 DNA Ligase [M0017170]

T4-Endonuclease II [M0006009]

T4-Monodeiodinase [M0011633]

T6 Antigens [M0001417]

T7 Endolysin [M0014393]

T7 Lysozyme [M0014394]

T7-Endonuclease I [M0006011]

Tachykinins [M0023589]
A family of biologically active peptides sharing a common conserved C-terminal sequence, -Phe-X-Gly-Leu-Met-NH2, where X is either an aromatic or a branched aliphatic amino acid. Members of this family have been found in mammals, amphibians, and mollusks. Tachykinins have diverse pharmacological actions in the central nervous system and the cardiovascular, genitourinary, respiratory, and gastrointestinal systems, as well as in glandular tissues. This diversity of activity is due to the existence of three or more subtypes of tachykinin receptors.

Tacrolimus Binding Protein 1A [M0182872]
A 12-KDa tacrolimus binding protein that is found associated with and may modulate the function of calcium release channels. It is a peptidyl-prolyl cis/trans isomerase which is inhibited by both tacrolimus (commonly called FK506) and SIROLIMUS.

Tacrolimus Binding Proteins [M0182899]
A family of immunophilin proteins that bind to the immunosuppressive drugs TACROLIMUS (also known as FK506) and SIROLIMUS. EC 5.2.1.-

Taka-Amylase A [M0000784]

Takus [M0003136]

Talin [M0025326]
A 235-kDa cytoplasmic protein that is also found in platelets. It has been localized to regions of cell-substrate adhesion. It binds to INTEGRINS; VINCULIN; and ACTINS and appears to participate in generating a transmembrane connection between the extracellular matrix and the cytoskeleton.

Talpha1 alpha-Tubulin [M0022143]

Tankyrases [M0416251]
A group of telomere associated proteins that interact with TRF1 PROTEIN, contain ANKYRIN REPEATS and have poly(ADP-ribose) polymerase activity.

TAP-144 [M0025474]

Taq Polymerase [M0029589]
A heat stable DNA-DIRECTED DNA POLYMERASE from the bacteria Thermus aquaticus. It is widely used for the amplification of genes through the process of POLYMERASE CHAIN REACTION. EC 2.7.7.-.

Target Membrane SNARE Proteins [M0472314]

Targocid [M0026326]

tat Protein [M0024079]

TATA Box Binding Protein-Like Proteins [M0213066]
A class of proteins related in structure and function to TATA-BOX BINDING PROTEIN that can take the place of TATA-BOX BINDING PROTEIN in the transcription initiation complex. They are found in most multicellular organisms and may be involved in tissue-specific promoter regulation. They bind to DNA and interact with TATA-BINDING PROTEIN ASSOCIATED FACTORS, however they may lack specificity for the TATA-BOX.

TATA-Binding Protein Associated Factors [M0407453]
Factors that associate with TATA-BOX BINDING PROTEIN. Many of them are components of TRANSCRIPTION FACTOR TFIID

TATA-Box Binding Protein [M0406970]
A general transcription factor that plays a major role in the activation of eukaryotic genes transcribed by RNA POLYMERASES. It binds specifically to the TATA BOX promoter element, which lies close to the position of transcription initiation in RNA transcribed by RNA POLYMERASE II. Although considered a principal component of TRANSCRIPTION FACTOR TFIID it also takes part in general transcription factor complexes involved in RNA POLYMERASE I and RNA POLYMERASE III transcription.

tau Proteins [M0025678]
Microtubule-associated proteins that are mainly expressed in neurons. Tau proteins constitute several isoforms and play an important role in the assembly of tubulin monomers into microtubules and in maintaining the cytoskeleton and axonal transport. Aggregation of specific sets of tau proteins in filamentous inclusions is the common feature of intraneuronal and glial fibrillar lesions (NEUROFIBRILLARY TANGLES; NEUROPIL THREADS) in numerous neurodegenerative disorders (ALZHEIMER DISEASE; TAUOPATHIES).

tau-Crystallins [M0005397]
A type of crystallin that has been found in the lens (LENS, CRYSTALLINE) of certain species of VERTEBRATES. They are inactivated form of PHOSPHOPYRUVATE HYDRATASE.

tau-Transferrin [M0021808]

Taurine [M0021065]
A conditionally essential nutrient, important during mammalian development. It is present in milk but is isolated mostly from ox bile and strongly conjugates bile acids.

Taurine Hydrochloride [M0329633]

Taurine Zinc Salt (2:1) [M0329632]

Taurine, Monopotassium Salt [M0329631]

tBid Protein [M0440614]
A C-terminal fragment of Bid protein that is produced by caspase cleavage. tBID is the active from of the protein and it redistributes from the CYTOSOL to MITOCHONDRIA to promote release of CYTOCHROME C.

Tc 99m-Albumin [M0021096]

TCF Transcription Factors [M0481948]
A family of DNA-binding proteins that are primarily expressed in T-LYMPHOCYTES. They interact with BETA CATENIN and serve as transcriptional activators and repressors in a variety of developmental processes.

Tdt Antigen [M0006658]

TechneScan MAG3 [M0352121]

Technetium Tc 99m Aggregated Albumin [M0021095]
A gamma-emitting radionuclide imaging agent used for the diagnosis of diseases in many tissues, particularly in cardiovascular and cerebral circulation.

Technetium Tc 99m Mertiatide [M0026202]
A technetium diagnostic aid used in renal function determination.

Teichomycin A2 [M0329318]

Teicoplanin [M0026325]
Glycopeptide antibiotic complex from Actinoplanes teichomyceticus active against gram-positive bacteria. It consists of five major components each with a different fatty acid moiety.

Telomer-Binding Protein, alpha-Subunit [M0194749]

Telomer-Binding Protein, beta-Subunit [M0406931]

Telomerase [M0028508]
An essential ribonucleoprotein reverse transcriptase that adds telomeric DNA to the ends of eukaryotic CHROMOSOMES.

Telomerase Catalytic Subunit [M0496628]

Telomere Repeat Binding Proteins [M0194759]

Telomere-Binding Proteins [M0194762]
Proteins that specifically bind to TELOMERES. Proteins in this class include those that perform functions such as telomere capping, telomere maintenance and telomere stabilization.

Telomeric Repeat Binding Protein 1 [M0194748]
A ubiquitously expressed telomere-binding protein that is present at TELOMERES throughout the CELL CYCLE. It is a suppressor of telomere elongation and may be involved in stabilization of telomere length. It is structurally different from TELOMERIC REPEAT BINDING PROTEIN 2 in that it contains acidic N-terminal amino acid residues.

Telomeric Repeat Binding Protein 2 [M0282405]
A ubiquitously expressed telomere-binding protein that is present at TELOMERES throughout the cell cycle. It is a suppressor of telomere elongation and may be involved in stabilization of telomere length. It is structurally different from TELOMERIC REPEAT BINDING PROTEIN 1 in that it contains basic N-terminal amino acid residues.

Tenascin [M0028456]
Hexameric extracellular matrix glycoprotein transiently expressed in many developing organs and often re-expressed in tumors. It is present in the central and peripheral nervous systems as well as in smooth muscle and tendons. (From Kreis & Vale, Guidebook to the Extracellular Matrix and Adhesion Proteins, 1993, p93)

Tenso Stop [M0482930]

Teprotide [M0021171]
A synthetic nonapeptide (Pyr-Trp-Pro-Arg-Pro-Gln-Ile-Pro-Pro) which is identical to the peptide from the venom of the snake, Bothrops jararaca. It inhibits kininase II and ANGIOTENSIN I and has been proposed as an antihypertensive agent.

Teriparatide [M0028836]
A synthetic polypeptide that consists of the 1-34 amino-acid fragment of human PARATHYROID HORMONE, the biologically active N-terminal region. The acetate form is given by intravenous infusion in the differential diagnosis of HYPOPARATHYROIDISM and PSEUDOHYPOPARATHYROIDISM. (Reynolds JEF(Ed): Martindale: The Extra Pharmacopoeia (electronic version). Micromedex, Inc, Englewood, CO, 1995)

Teriparatide Acetate [M0028838]

Termination Release Factor [M0016237]

Ternary Complex Factors [M0477929]
A subclass of c-ets proto-oncogene proteins that were first described by their property of binding to DNA when associated with other regulatory proteins such as SERUM RESPONSE FACTOR. They contain an amino-terminal ets domain that binds to DNA along with centrally located SERUM RESPONSE FACTOR interacting domain, and carboxy-terminal map kinase activation domains. They play an important role in transcriptional regulation by INTRACELLULAR SIGNALING PEPTIDES AND PROTEINS.

Testosterone 5-alpha-Reductase [M0021199]

Testosterone Dehydrogenases [M0023180]

Tetragastrin [M0021228]
L-Tryptophyl-L-methionyl-L-aspartyl-L-phenylalaninamide. The C-terminal tetrapeptide of gastrin. It is the smallest peptide fragment of gastrin which has the same physiological and pharmacological activity as gastrin.

Tetrahydrofolate Dehydrogenase [M0021232]
An enzyme of the oxidoreductase class that catalyzes the reaction 7,8-dihyrofolate and NADPH to yield 5,6,7,8-tetrahydrofolate and NADPH+, producing reduced folate for amino acid metabolism, purine ring synthesis, and the formation of deoxythymidine monophosphate. Methotrexate and other folic acid antagonists used as chemotherapeutic drugs act by inhibiting this enzyme. (Dorland, 27th ed) EC 1.5.1.3.

Tetraiodothyronine 5'-Deiodinase [M0011634]

TFIIIB-alpha [M0398435]

TFIIIB-beta [M0398436]

Thermolysin [M0021305]
A thermostable extracellular metalloendopeptidase containing four calcium ions. (Enzyme Nomenclature, 1992) 3.4.24.27.

Thermolysin S [M0021306]

theta-Globin [M0009289]

Thiactin [M0373340]

Thiamin Pyrophosphokinase [M0021324]
An enzyme that catalyzes the formation of thiamine pyrophosphate from ATP and thiamine. EC 2.7.6.2.

Thiamin-Triphosphatase [M0021325]
An enzyme present in nerve tissue. It catalyzes reversibly the formation of thiamine diphosphate and orthophosphate from thiamine triphosphate. EC 3.6.1.28.

Thiamine Pyrophosphatase [M0021322]
An enzyme that hydrolyzes thiamine pyrophosphate to thiamine monophosphate plus inorganic phosphate. EC 3.6.1.-.

Thiodril [M0372312]

Thioesterase I [M0015781]

Thiol-Disulfide Oxidoreductase [M0017858]

Thiola [M0373099]

Thiolester Hydrolases [M0021359]

Thiopronine [M0013445]
Sulfhydryl acylated derivative of GLYCINE.

Thioredoxin [M0021373]
A hydrogen-carrying protein that participates in a variety of biochemical reactions including ribonucleotide reduction. Thioredoxin is oxidized from a dithiol to a disulfide during ribonucleotide reduction. The disulfide form is then reduced by NADPH in a reaction catalyzed by THIOREDOXIN REDUCTASE.

Thioredoxin M [M0021374]

Thioredoxin Reductase (NADPH) [M0021375]
A FLAVOPROTEIN enzyme that catalyzes the oxidation of THIOREDOXIN to thioredoxin disulfide in the presence of NADP+. It was formerly listed as EC 1.6.4.5

Thiostatin [M0012053]

Thiostrepton [M0021380]
One of the CYCLIC PEPTIDES from Streptomyces that is active against gram-positive bacteria. In veterinary medicine, it has been used in mastitis caused by gram-negative organisms and in dermatologic disorders.

Thiosulfate Sulfurtransferase [M0021381]
An enzyme that catalyzes the transfer of the planetary sulfur atom of thiosulfate ion to cyanide ion to form thiocyanate ion. EC 2.8.1.1.

Thomaegelin [M0475083]

Threonine [M0021415]
An essential amino acid occurring naturally in the L-form, which is the active form. It is found in eggs, milk, gelatin, and other proteins.

Threonine Dehydratase [M0021416]
A pyridoxal-phosphate protein that catalyzes the deamination of THREONINE to 2-ketobutyrate and AMMONIA. The role of this enzyme can be biosynthetic or biodegradative. In the former role it supplies 2-ketobutyrate required for ISOLEUCINE biosynthesis, while in the latter it is only involved in the breakdown of threonine to supply energy. This enzyme was formerly listed as EC 4.2.1.16.

Threonine-tRNA Ligase [M0021417]
An enzyme that activates threonine with its specific transfer RNA. EC 6.1.1.3.

Thrombate III [M0434014]

Thrombin [M0021424]
An enzyme formed from PROTHROMBIN that converts FIBRINOGEN to FIBRIN.

Thrombin Receptor Activating Peptides [M0445097]
A cryptic peptide ligand contained within the N-terminal of the thrombin receptor.

Thrombinar [M0373253]

Thrombolysin [M0372964]

Thrombomodulin [M0027407]
A cell surface glycoprotein of endothelial cells that binds thrombin and serves as a cofactor in the activation of protein C and its regulation of blood coagulation.

Thromboplastin [M0021433]
Constituent composed of protein and phospholipid that is widely distributed in many tissues. It serves as a cofactor with factor VIIa to activate factor X in the extrinsic pathway of blood coagulation.

Thrombopoietin [M0021434]
A humoral factor that stimulates the production of thrombocytes (BLOOD PLATELETS). Thrombopoietin stimulates the proliferation of bone marrow MEGAKARYOCYTES and their release of blood platelets. The process is called THROMBOPOIESIS.

Thrombospondin 1 [M0029254]
An extracellular matrix glycoprotein from platelets and a variety of normal and transformed cells of both mesenchymal and epithelial origin. Thrombospondin-1 is believed to play a role in cell migration and proliferation, during embryogenesis and wound repair. Also, it has been studied for its use as a potential regulator of tumor growth and metastasis.

Thrombospondins [M0029253]
A family of related, adhesive glycoproteins which are synthesized, secreted, and incorporated into the extracellular matrix of a variety of cells, including alpha granules of platelets following thrombin activation and endothelial cells. They interact with a number of BLOOD COAGULATION FACTORS and anticoagulant factors. Five distinct forms have been identified, thrombospondin 1, -2, -3, -4, and cartilage oligomeric matrix protein (COMP). They are involved in cell adhesion, platelet aggregation, cell proliferation, angiogenesis, tumor metastasis, vascular smooth muscle growth, and tissue repair.

Thrombostat [M0373252]

Thromboxane-A Synthase [M0021440]
An enzyme found predominantly in platelet microsomes. It catalyzes the conversion of PGG(2) and PGH(2) (prostaglandin endoperoxides) to thromboxane A2. EC 5.3.99.5.

Thy-1.1 Antigen [M0028148]

Thy-1.2 Antigen [M0028147]

Thymic Factor, Circulating [M0021445]
A thymus-dependent nonapeptide found in normal blood. Stimulates the formation of E rosettes and is believed to be involved in T-cell differentiation.

Thymidine Kinase [M0021448]
An enzyme that catalyzes the conversion of ATP and thymidine to ADP and thymidine 5'-phosphate. Deoxyuridine can also act as an acceptor and dGTP as a donor. (From Enzyme Nomenclature, 1992) EC 2.7.1.21.

Thymidine Phosphorylase [M0021452]
The enzyme catalyzing the transfer of 2-deoxy-D-ribose from thymidine to orthophosphate, thereby liberating thymidine. EC 2.4.2.4.

Thymidylate Synthase [M0021454]
An enzyme of the transferase class that catalyzes the reaction 5,10-methylenetetrahydrofolate and dUMP to dihydrofolate and dTMP in the synthesis of thymidine triphosphate. (From Dorland, 27th ed) EC 2.1.1.45.

Thymine DNA Glycosylase [M0073437]
An enzyme that removes THYMINE and URACIL bases mispaired with GUANINE through hydrolysis of their N-glycosidic bond. These mispaired nucleotides generally occur through the hydrolytic DEAMINATION of 5-METHYLCYTOSINE to thymine.

Thymopoietin I [M0021461]

Thymopoietin II [M0021462]

Thymopoietins [M0021463]
Two closely related polypeptides (molecular weight 7,000) isolated from the thymus gland. These hormones induce the differentiation of prothymocytes to thymocytes within the thymus. They also cause a delayed impairment of neuromuscular transmission in vivo and are therefore believed to be the agent responsible for myasthenia gravis.

Thymosin [M0021464]
Thymosin. A family of heat-stable, polypeptide hormones secreted by the thymus gland. Their biological activities include lymphocytopoiesis, restoration of immunological competence and enhancement of expression of T-cell characteristics and function. They have therapeutic potential in patients having primary or secondary immunodeficiency diseases, cancer or diseases related to aging.

Thymosin Fs [M0021465]

Thypinone [M0021501]

Thyrax [M0463511]

Thyreoliberin [M0021502]

Thyroglobulin [M0021472]

Thyroid Galactosyltransferase [M0009491]

Thyroid Hormone Receptor alpha-1 [M0411714]
An isoform produced by alternative splicing.

Thyroid Hormone Receptor alpha-2 [M0411715]
An isoform produced by alternative splicing.

Thyroid Hormone Receptor beta-1 [M0411731]
An isoform produced by alternative splicing.

Thyroid Hormone Receptor beta-2 [M0411732]
An isoform produced by alternative splicing.

Thyroid Hormone Receptors alpha [M0018633]
High affinity receptors for THYROID HORMONES, especially TRIIODOTHYRONINE. These receptors are usually found in the nucleus where they regulate DNA transcription. They are encoded by the THRA gene (also known as NR1A1, THRA1, ERBA or ERBA1 gene) as several isoforms produced by alternative splicing.

Thyroid Hormone Receptors beta [M0018634]
High affinity receptors for THYROID HORMONES, especially TRIIODOTHYRONINE. These receptors are usually found in the nucleus where they regulate DNA transcription. They are encoded by the THRB gene (also known as NR1A2, THRB1, or ERBA2 gene) as several isoforms produced by alternative splicing. Mutations in the THRB gene cause THYROID HORMONE RESISTANCE SYNDROME.

Thyroid Hormones [M0021484]
Natural hormones secreted by the THYROID GLAND, such as THYROXINE, and their synthetic analogs.

Thyronine [M0021494]

Thyronines [M0021493]
A group of metabolites derived from THYROXINE and TRIIODOTHYRONINE via the peripheral enzymatic removal of iodines from the thyroxine nucleus. Thyronine is the thyroxine nucleus devoid of its four iodine atoms.

Thyropexin [M0021506]

Thyrotropin [M0021496]
A glycoprotein hormone secreted by the adenohypophysis (PITUITARY GLAND, ANTERIOR). Thyrotropin stimulates THYROID GLAND by increasing the iodide transport, synthesis and release of thyroid hormones (THYROXINE and TRIIODOTHYRONINE). Thyrotropin consists of two noncovalently linked subunits, alpha and beta. Within a species, the alpha subunit is common in the pituitary glycoprotein hormones (TSH; LUTEINIZING HORMONE and FSH), but the beta subunit is unique and confers its biological specificity.

Thyrotropin, beta Subunit [M0114339]
The beta subunit of thyroid stimulating hormone, thyrotropin. It is a 112-amino acid glycopolypeptide of about 16 kD. Full biological activity of TSH requires the non-covalently bound heterodimers of an alpha and a beta subunit.

Thyroxine [M0021504]
The major hormone derived from the thyroid gland. Thyroxine is synthesized via the iodination of tyrosines (MONOIODOTYROSINE) and the coupling of iodotyrosines (DIIODOTYROSINE) in the THYROGLOBULIN. Thyroxine is released from thyroglobulin by proteolysis and secreted into the blood. Thyroxine is peripherally deiodinated to form TRIIODOTHYRONINE which exerts a broad spectrum of stimulatory effects on cell metabolism.

Thyroxine 5'-Deiodinase [M0011635]

Thyroxine 5'-Monodeiodinase [M0011636]

Thyroxine Converting Enzyme [M0011637]

Thyroxine-Binding Globulin [M0021507]

Thyroxine-Binding Prealbumin [M0021508]

Thyroxine-Binding Proteins [M0021505]
A group of proteins that includes thyroxine-binding globulin, a glycoprotein that serves as the major and specific carrier of thyroxine in plasma, accounting for 70-75% of the bound thyroxine; thyroxine-binding prealbumin, an albumin that serves as the secondary carrier, accounting for between 20 and 25% of the bound thyroxine; and serum albumin, which accounts for the remaining bound thyroxine.

Tiroidine [M0463517]

Tiroxina Leo [M0463518]

Tisseel [M0373272]

Tissucol [M0373277]

Tissue Inhibitor of Metalloproteinase-1 [M0029271]
A member of the family of TISSUE INHIBITOR OF METALLOPROTEINASES. It is a N-glycosylated protein, molecular weight 28 kD, produced by a vast range of cell types and found in a variety of tissues and body fluids. It has been shown to suppress metastasis and inhibit tumor invasion in vitro.

Tissue Inhibitor of Metalloproteinase-2 [M0029272]
A member of the family of TISSUE INHIBITOR OF METALLOPROTEINASES. It is a 21-kDa nonglycosylated protein found in tissue fluid and is secreted as a complex with progelatinase A by human fibroblast and uncomplexed from alveolar macrophages. An overexpression of TIMP-2 has been shown to inhibit invasive and metastatic activity of tumor cells and decrease tumor growth in vivo.

Tissue Inhibitor of Metalloproteinase-3 [M0029273]
A member of the family of tissue inhibitor of metalloproteinases. Mutations of the gene for TIMP3 protein causes Sorsby fundus dystrophy.

Tissue Inhibitor of Metalloproteinases [M0029270]
A family of secreted proteins (TIMP-1; TIMP-2; and TIMP-3) that play a crucial role in regulating the activity of the secreted METALLOENDOPEPTIDASES; (COLLAGENASES; stromelysins; GELATINASES). Of the three characterized, only TIMP-1 and TIMP-2 appear to have related primary structures and inhibitory properties. They influence the activation of the prometalloproteinase and act to modulate proteolysis of extracellular matrix, notably during tissue remodeling and inflammatory processes. On certain cell types, they can exhibit growth factor-like activity, and they can inhibit the tumorigenic and metastatic phenotype in cancer cells. (Pharmacol Ther 1993;59:329-41)

Tissue Kallikreins [M0328361]
A family of trypsin-like SERINE ENDOPEPTIDASES that are expressed in a variety of cell types including human prostate epithelial cells. They are formed from tissue prokallikrein by action with TRYPSIN. They are highly similar to PROSTATE-SPECIFIC ANTIGEN. EC 3.4.21.35.

Tissue Plasminogen Activator [M0016991]
A proteolytic enzyme in the serine protease family found in many tissues which converts PLASMINOGEN to PLASMIN. It has fibrin-binding activity and is immunologically different from URINARY PLASMINOGEN ACTIVATOR. The primary sequence, composed of 527 amino acids, is identical in both the naturally occurring and synthetic proteases. EC 3.4.21.68.

Tissue Polypeptide Antigen [M0028860]
Serological tumor marker composed of a molecular complex of cytokeratins 8, 18, and 19. It is used in the diagnosis and staging of bronchogenic carcinoma.

TNF Receptor-Associated Death Domain Protein [M0235445]
A 34 kDa signal transducing adaptor protein that associates with TUMOR NECROSIS FACTOR RECEPTOR TYPE 1. It facilitates the recruitment of signaling proteins such as TNF RECEPTOR-ASSOCIATED FACTOR 2 and FAS ASSOCIATED DEATH DOMAIN PROTEIN to the receptor complex.

TNF Receptor-Associated Factor 1 [M0235447]
A signal transducing tumor necrosis factor receptor associated factor that is involved in TNF RECEPTOR feedback regulation. It is similar in structure and appears to work in conjunction with TNF RECEPTOR-ASSOCIATED FACTOR 2 to inhibit APOPTOSIS.

TNF Receptor-Associated Factor 2 [M0235451]
A signal transducing tumor necrosis factor receptor associated factor that is involved in TNF RECEPTOR feedback regulation. It is similar in structure and appears to work in conjunction with TNF RECEPTOR-ASSOCIATED FACTOR 1 to inhibit APOPTOSIS.

TNF Receptor-Associated Factor 3 [M0243876]
A signal transducing tumor necrosis factor receptor associated factor that is involved in regulation of NF-KAPPA B signaling and activation of MITOGEN-ACTIVATED PROTEIN KINASES.

TNF Receptor-Associated Factor 4 [M0253606]
A widely expressed member of the TNF receptor-associated family that may play a role in neuronal development and EMBRYOGENESIS. Although TNF receptor-associated factor 4 does not strongly associate with TUMOR NECROSIS FACTOR RECEPTORS it may be a signaling partner with the GLUCOCORTICOID-INDUCED TNFR-RELATED PROTEIN that plays a role in the activation of JNK MITOGEN-ACTIVATED PROTEIN KINASES and NF-KAPPA B.

TNF Receptor-Associated Factor 5 [M0262278]
A signal transducing tumor necrosis factor receptor associated factor that mediates signaling from CD27 ANTIGENS; CD40 ANTIGENS; and the LYMPHOTOXIN BETA RECEPTOR. It is involved in regulation of NF-KAPPA B signaling.

TNF Receptor-Associated Factor 6 [M0266280]
A signal transducing tumor necrosis factor receptor associated factor that is involved in regulation of NF-KAPPA B signalling and activation of JNK MITOGEN-ACTIVATED PROTEIN KINASES.

TNF-Related Apoptosis-Inducing Ligand [M0256022]
A transmembrane-protein belonging to the TNF family of intercellular signaling proteins. It is a widely expressed ligand that activates APOPTOSIS by binding to TNF-RELATED APOPTOSIS-INDUCING LIGAND RECEPTORS. The membrane-bound form of the protein can be cleaved by specific CYSTEINE ENDOPEPTIDASES to form a soluble ligand form.

TNF-sR75 [M0232365]

TNFR p80 [M0232367]

Toll-Like Receptor 1 [M0377894]
A pattern recognition receptor that forms heterodimers with TOLL-LIKE RECEPTOR 2.

Toll-Like Receptor 10 [M0479625]
A pattern recognition receptor that is expressed in LUNG and in B-LYMPHOCYTES.

Toll-Like Receptor 2 [M0286280]
A pattern recognition receptor that forms heterodimers with other TOLL-LIKE RECEPTORS. It interacts with multiple ligands including PEPTIDOGLYCAN, bacterial LIPOPROTEINS, lipoarabinomannan, and a variety of PORINS.

Toll-Like Receptor 3 [M0479621]
A pattern recognition receptor that binds DOUBLE-STRANDED RNA. It mediates cellular responses to certain viral pathogens.

Toll-Like Receptor 4 [M0460195]
A pattern recognition receptor that interacts with LYMPHOCYTE ANTIGEN 96 and LIPOPOLYSACCHARIDES. It mediates cellular responses to GRAM-NEGATIVE BACTERIA.

Toll-Like Receptor 5 [M0479622]
A pattern recognition receptor that binds FLAGELLIN. It mediates cellular responses to certain bacterial pathogens.

Toll-Like Receptor 6 [M0306173]
A pattern recognition receptor that forms heterodimers with TLR2 RECEPTOR. The complex interacts with a variety of ligands including LIPOPROTEINS from MYCOPLASMA.

Toll-Like Receptor 7 [M0479623]
A pattern recognition receptor that binds several forms of imidazo-quinoline including the antiviral compound Imiquimod.

Toll-Like Receptor 8 [M0479624]
A pattern recognition receptor that recognizes GUANOSINE and URIDINE-rich single-stranded RNA.

Toll-Like Receptor 9 [M0376024]
A pattern recognition receptor that binds unmethylated CPG CLUSTERS. It mediates cellular responses to bacterial pathogens by distinguishing between self and bacterial DNA.

Toll-Like Receptors [M0286281]
A family of pattern recognition receptors characterized by an extracellular leucine-rich domain and a cytoplasmic domain that share homology with the INTERLEUKIN 1 RECEPTOR and the DROSOPHILA toll protein. Following pathogen recognition, toll-like receptors recruit and activate a variety of SIGNAL TRANSDUCING ADAPTOR PROTEINS.

Topitracin [M0454535]

Tosylarginine Methyl Ester [M0021713]
Arginine derivative which is a substrate for many proteolytic enzymes. As a substrate for the esterase from the first component of complement, it inhibits the action of C(l) on C(4).

Tosyllysine Chloromethyl Ketone [M0021714]
An inhibitor of SERINE ENDOPEPTIDASES. Acts as an alkylating agent and is known to interfere with the translation process.

Tosylphenylalanyl Chloromethyl Ketone [M0021715]
An inhibitor of Serine Endopeptidases. Acts as alkylating agent and is known to interfere with the translation process.

Totazina [M0372332]

TRAF and TNF Receptor-Associated Proteins [M0366070]

TRAF-Interacting Proteins [M0275223]

Trans-Acting Transcription Factor, HIV [M0024080]

Trans-Activator Protein, HIV [M0024074]

Trans-Activators [M0023900]
Diffusible gene products that act on homologous or heterologous molecules of viral or cellular DNA to regulate the expression of proteins.

Trans-Cinnamate 4-Monooxygenase [M0072907]
A member of the P450 superfamily, this enzyme catalyzes the first oxidative step of the phenylpropanoid pathway in higher PLANTS by transforming trans-cinnamate into p-coumarate.

Transaldolase [M0021773]
An enzyme of the transferase class that catalyzes the reaction sedoheptulose 7-phosphate and D-glyceraldehyde 3-phosphate to yield D-erythrose 4-phosphate and D-fructose phosphate in the PENTOSE PHOSPHATE PATHWAY. (Dorland, 27th ed) EC 2.2.1.2.

Transaldolase B [M0021774]

Transaminases [M0000972]
A subclass of enzymes of the transferase class that catalyze the transfer of an amino group from a donor (generally an amino acid) to an acceptor (generally a 2-keto acid). Most of these enzymes are pyridoxyl phosphate proteins. (Dorland, 28th ed) EC 2.6.1.

Transamine [M0021845]

Transcobalamin I [M0021780]

Transcobalamin II [M0021781]

Transcobalamin III [M0021782]

Transcobalamins [M0021783]
A group of carrier proteins which bind with VITAMIN B12 in the BLOOD and aid in its transport. Transcobalamin I migrates electrophoretically as a beta-globulin, while transcobalamins II and III migrate as alpha-globulins.

Transcortin [M0021786]

Transcriptase [M0019149]

Transcription Factor AP-1 [M0028161]
A multiprotein complex composed of the products of c-jun and c-fos proto-oncogenes. These proteins must dimerize in order to bind to the AP-1 recognition site, also known as the TPA-responsive element (TRE). AP-1 controls both basal and inducible transcription of several genes.

Transcription Factor AP-2 [M0151839]
A family of DNA binding proteins that regulate expression of a variety of GENES during CELL DIFFERENTIATION and APOPTOSIS. Family members contain a highly conserved carboxy-terminal basic HELIX-TURN-HELIX MOTIF involved in dimerization and sequence-specific DNA binding.

Transcription Factor AP-2 alpha Protein [M0396304]

Transcription Factor AP-2 beta Protein [M0151827]

Transcription Factor AP-2 delta Protein [M0406061]

Transcription Factor AP-2 epsilon Protein [M0460860]

Transcription Factor AP-2 gamma Protein [M0151828]

Transcription Factor Brn-3 [M0208059]
A family of mammalian POU domain factors that are expressed predominately in NEURONS.

Transcription Factor Brn-3A [M0208056]
A POU domain factor that activates GENETIC TRANSCRIPTION of GENES encoding NEUROFILAMENT PROTEINS; alpha internexin; SYNAPTOSOMAL-ASSOCIATED PROTEIN 25; and BCL-2 PROTO-ONCOGENE PROTEINS.

Transcription Factor Brn-3B [M0208057]
A POU domain factor that represses GENETIC TRANSCRIPTION of GENES encoding NEUROFILAMENT PROTEINS, alpha internexin, and SYNAPTOSOMAL-ASSOCIATED PROTEIN 25.

Transcription Factor Brn-3C [M0208058]
A POU domain factor that activates neuronal cell GENETIC TRANSCRIPTION of GENES encoding NEUROFILAMENT PROTEINS, alpha internexin, and SYNAPTOSOMAL-ASSOCIATED PROTEIN 25. Mutations in the Brn-3c gene have been associated with DEAFNESS.

Transcription Factor CHOP [M0204031]
A CCAAT-enhancer binding protein that is induced by DNA DAMAGE and growth arrest. It serves as a dominant negative inhibitor of other CCAAT-enhancer binding proteins.

Transcription Factor DP1 [M0270783]
A transcription factor that possesses DNA-binding and E2F-binding domains but lacks a transcriptional activation domain. It is a binding partner for E2F TRANSCRIPTION FACTORS and enhances the DNA binding and transactivation function of the DP-E2F complex.

Transcription Factor Pit-1 [M0177779]
A POU domain factor that regulates expression of GROWTH HORMONE; PROLACTIN; and THYROTROPIN-BETA in the ANTERIOR PITUITARY GLAND.

Transcription Factor Pit-2 [M0177775]

Transcription Factor RelA [M0214240]
A subunit of NF-kappa B that is primarily responsible for its transactivation function. It contains a C-terminal transactivation domain and an N-terminal domain with homology to PROTO-ONCOGENE PROTEINS C-REL.

Transcription Factor RelB [M0201037]
A transcription factor that takes part in the NF-kappa-B complex by interacting with NF-KAPPA B P50 SUBUNIT or NF-KAPPA B P52 SUBUNIT. It regulates GENETIC TRANSCRIPTION that is involved in immune and inflammatory responses.

Transcription Factor TFIIA [M0171342]
An RNA POLYMERASE II specific transcription factor. It may play a role in transcriptional activation of gene expression by interacting with the TATA-BOX BINDING PROTEIN component of TRANSCRIPTION FACTOR TFIID.

Transcription Factor TFIIB [M0182486]
An RNA POLYMERASE II specific transcription factor. It plays a role in assembly of the pol II transcriptional preinitiation complex and has been implicated as a target of gene-specific transcriptional activators.

Transcription Factor TFIID [M0159351]
The major sequence-specific DNA-binding component involved in the activation of transcription of RNA POLYMERASE II. It was originally described as a complex of TATA-BOX BINDING PROTEIN and TATA-BINDING PROTEIN ASSOCIATED FACTORS. It is now know that TATA BOX BINDING PROTEIN-LIKE PROTEINS may take the place of TATA-box binding protein in the complex.

Transcription Factor TFIIH [M0206107]
A general transcription factor that is involved in basal GENETIC TRANSCRIPTION and NUCLEOTIDE EXCISION REPAIR. It consists of nine subunits including ATP-DEPENDENT DNA HELICASES; CYCLIN H; and XERODERMA PIGMENTOSUM GROUP D PROTEIN.

Transcription Factor TFIIIA [M0122836]
One of several general transcription factors that are specific for RNA POLYMERASE III. It is a zinc finger (ZINC FINGERS) protein and is required for transcription of 5S ribosomal genes.

Transcription Factor TFIIIB [M0149357]
One of several general transcription factors that are specific for RNA POLYMERASE III. TFIIIB recruits and positions pol III over the initiation site and remains stably bound to the DNA through multiple rounds of re-initiation by RNA POLYMERASE III.

Transcription Factors [M0021788]
Endogenous substances, usually proteins, which are effective in the initiation, stimulation, or termination of the genetic transcription process.

Transcription Factors, General [M0198210]
Transcription factors that form transcription initiation complexes on DNA, bind to specific DNA-DIRECTED RNA POLYMERASES and are required to initiate transcription. Although their binding may be localized to distinct sequence and structural motifs within the DNA they are considered non-specific with regard to the specific gene being transcribed.

Transcription Factors, TFII [M0028965]
The so-called general transcription factors that bind to RNA POLYMERASE II and that are required to initiate transcription. They include TFIIA; TFIIB; TFIID; TFIIE; TFIIF; TFIIH; TFII-I; and TFIIJ. In vivo they apparently bind in an ordered multi-step process and/or may form a large preinitiation complex called RNA polymerase II holoenzyme.

Transcription Factors, TFIII [M0028966]
Factors that bind to RNA POLYMERASE III and aid in transcription. They include the assembly factors TFIIIA and TFIIIC and the initiation factor TFIIIB. All combine to form a preinitiation complex at the promotor that directs the binding of RNA POLYMERASE III.

Transcriptional Elongation Factors [M0407954]
Transcription factors whose primary function is to regulate the rate in which RNA is transcribed.

Transcriptional Elongation Inhibitory Factors [M0407955]

Transducin [M0023545]
A heterotrimeric GTP-binding protein that mediates the light activation signal from photolyzed rhodopsin to cyclic GMP phosphodiesterase and is pivotal in the visual excitation process. Activation of rhodopsin on the outer membrane of rod and cone cells causes GTP to bind to transducin followed by dissociation of the alpha subunit-GTP complex from the beta/gamma subunits of transducin. The alpha subunit-GTP complex activates the cyclic GMP phosphodiesterase which catalyzes the hydrolysis of cyclic GMP to 5'-GMP. This leads to closure of the sodium and calcium channels and therefore hyperpolarization of the rod cells. EC 3.6.1.-.

Transferases [M0021801]
Transferases are enzymes transferring a group, for example, the methyl group or a glycosyl group, from one compound (generally regarded as donor) to another compound (generally regarded as acceptor). The classification is based on the scheme "donor:acceptor group transferase". (Enzyme Nomenclature, 1992) EC 2.

Transferases (Other Substituted Phosphate Groups) [M0026978]
A class of enzymes that transfers substituted phosphate groups. EC 2.7.8.

Transferrin [M0021810]
Serum beta-globulin that binds and transports iron. (From Dorland, 28th ed)

Transferrin B [M0021811]

Transferrin C [M0021809]

Transferrin-Binding Protein A [M0084815]
A subtype of bacterial transferrin-binding protein found in bacteria. It forms a cell surface receptor complex with TRANSFERRIN-BINDING PROTEIN B.

Transferrin-Binding Protein B [M0084822]
A subtype of bacterial transferrin-binding protein found in bacteria. It forms a cell surface receptor complex with TRANSFERRIN-BINDING PROTEIN A.

Transferrin-Binding Proteins [M0404225]
A class of carrier proteins that bind to TRANSFERRIN. Many strains of pathogenic bacteria utilize transferrin-binding proteins to acquire their supply of iron from serum.

Transforming Growth Factor alpha [M0024756]
Factor isolated in a variety of tissues including epithelium, and maternal decidua. It is closely related to EPIDERMAL GROWTH FACTOR and binds to the EGF receptor. TGF-alpha acts synergistically with TGF-beta in inducing phenotypic transformation, but its physiological role is unknown.

Transforming Growth Factor beta [M0024757]
A factor synthesized in a wide variety of tissues. It acts synergistically with TGF-alpha in inducing phenotypic transformation and can also act as a negative autocrine growth factor. TGF-beta has a potential role in embryonal development, cellular differentiation, hormone secretion, and immune function. TGF-beta is found mostly as homodimer forms of separate gene products TGF-beta1, TGF-beta2 or TGF-beta3. Heterodimers composed of TGF-beta1 and 2 (TGF-beta1.2) or of TGF-beta2 and 3 (TGF-beta2.3) have been isolated. The TGF-beta proteins are synthesized as precursor proteins.

Transforming Growth Factor beta 1 Latency Associated Peptide [M0202415]

Transforming Growth Factor beta 2 Latency Associated Peptide [M0496452]

Transforming Growth Factor beta 3 Latency Associated Peptide [M0496456]

Transforming Growth Factor beta1 [M0024760]
A subtype of transforming growth factor beta that is synthesized by a wide variety of cells. It is synthesized as a precursor molecule that is cleaved to form mature TGF-beta 1 and TGF-beta1 latency-associated peptide. The association of the cleavage products results in the formation a latent protein which must be activated to bind its receptor. Defects in the gene that encodes TGF-beta1 are the cause of CAMURATI-ENGELMANN SYNDROME.

Transforming Growth Factor beta2 [M0024759]
A TGF-beta subtype that was originally identified as a GLIOBLASTOMA-derived factor which inhibits the antigen-dependent growth of both helper and CYTOTOXIC T LYMPHOCYTES. It is synthesized as a precursor molecule that is cleaved to form mature TGF-beta2 and TGF-beta2 latency-associated peptide. The association of the cleavage products results in the formation a latent protein which must be activated to bind its receptor.

Transforming Growth Factor beta3 [M0358023]
A TGF-beta subtype that plays role in regulating epithelial-mesenchymal interaction during embryonic development. It is synthesized as a precursor molecule that is cleaved to form mature TGF-beta3 and TGF-beta3 latency-associated peptide. The association of the cleavage products results in the formation a latent protein which must be activated to bind its receptor.

Transforming Growth Factors [M0023538]
Hormonally active polypeptides that can induce the transformed phenotype when added to normal, non-transformed cells. They have been found in culture fluids from retrovirally transformed cells and in tumor-derived cells as well as in non-neoplastic sources. Their transforming activities are due to the simultaneous action of two otherwise unrelated factors, TRANSFORMING GROWTH FACTOR ALPHA and TRANSFORMING GROWTH FACTOR BETA.

Transglutaminases [M0017884]
Transglutaminases catalyze cross-linking of proteins at a GLUTAMINE in one chain with LYSINE in another chain. They include keratinocyte transglutaminase (TGM1 or TGK), tissue transglutaminase (TGM2 or TGC), plasma transglutaminase involved with coagulation (FACTOR XIII and FACTOR XIIIa), hair follicle transglutaminase, and prostate transglutaminase. Although structures differ, they share an active site (YGQCW) and strict CALCIUM dependence.

Transglutine [M0373276]

Transhydroxymethylases [M0029513]

Transient Receptor Potential Channels [M0472345]
A broad group of eukaryotic six-transmembrane cation channels that are classified by sequence homology because their functional involvement with SENSATION is varied. They have only weak voltage sensitivity and ion selectivity. They are named after a DROSOPHILA mutant that displayed transient receptor potentials in response to light. A 25-amino-acid motif containing a TRP box (EWKFAR) just C-terminal to S6 is found in TRPC, TRPV and TRPM subgroups. ANKYRIN repeats are found in TRPC, TRPV & TRPN subgroups. Some are functionally associated with TYROSINE KINASE or PHOSPHOLIPASE C.

Transketolase [M0021825]
An enzyme of the transferase class that catalyzes the conversion of sedoheptulose 7-phosphate and D-glyceraldehyde 3-phosphate to D-ribose 5-phosphate and D-xylulose 5-phosphate in the PENTOSE PHOSPHATE PATHWAY. (Dorland, 27th ed) EC 2.2.1.1.

Transmembrane Activator and CAML Interactor Protein [M0492355]
A tumor necrosis factor receptor superfamily member found expressed on peripheral B-LYMPHOCYTES. It has specificity for B-CELL MATURATION ANTIGEN and TUMOR NECROSIS FACTOR LIGAND SUPERFAMILY MEMBER 13.

Transposases [M0029539]
Enzymes that recombine DNA segments by a process which involves the formation of a synapse between two DNA helices, the cleavage of single strands from each DNA helix and the ligation of a DNA strand from one DNA helix to the other. The resulting DNA structure is called a Holliday junction which can be resolved by DNA REPLICATION or by HOLLIDAY JUNCTION RESOLVASES.

Transposon Resolvases [M0448784]
Recombinases that involved in the propagation of DNA TRANSPOSONS. They bind to transposon sequences found at two different sites along the same stretch of DNA and bring them into close proximity. The enzymes then catalyze the double strand cleavage, exchange of double strands and rejoining of DNA helices so that the DNA transposon is formed into a circular PLASMID.

Traskolan [M0011915]

Trasylol [M0011906]

Traumanase [M0002936]

Trehalase [M0021859]
An enzyme that catalyzes the conversion of alpha,alpha-trehalose and water to D-glucose. EC 3.2.1.28.

Tri-Sweet [M0001822]

Trichosanthin [M0024413]
Plant-derived ribosome-inactivating protein (RIP) purified from the Chinese medicinal herb tian-hua-fen which is obtained from the root tubers of Trichosanthes kirilowii. It has been used as an abortifacient and in the treatment of trophoblastic tumors. GLQ223 (Compound Q), a highly purified form of trichosanthin, has been proposed as antiviral treatment for AIDS.

Triiodothyronine [M0021977]
A T3 thyroid hormone normally synthesized and secreted by the thyroid gland in much smaller quantities than thyroxine (T4). Most T3 is derived from peripheral monodeiodination of T4 at the 5' position of the outer ring of the iodothyronine nucleus. The hormone finally delivered and used by the tissues is mainly T3.

Triiodothyronine Deiodinase [M0011638]

Triiodothyronine, Reverse [M0021978]
A metabolite of THYROXINE, formed by the peripheral enzymatic monodeiodination of T4 at the 5 position of the inner ring of the iodothyronine nucleus.

Triose-Phosphate Isomerase [M0022007]
An enzyme that catalyzes reversibly the conversion of D-glyceraldehyde 3-phosphate to dihydroxyacetone phosphate. A deficiency in humans causes nonspherocytic hemolytic disease (ANEMIA, HEMOLYTIC, CONGENITAL NONSPHEROCYTIC). EC 5.3.1.1.

Triptorelin [M0026318]
A potent synthetic long-acting agonist of GONADOTROPIN-RELEASING HORMONE with D-tryptophan substitution at residue 6.

Tristetraprolin [M0184858]
A ZINC FINGER MOTIF containing transcription factor that was originally identified as one of the IMMEDIATE-EARLY PROTEINS. It shuttles between the CYTOPLASM and the CELL NUCLEUS and is involved in destabilization of mRNAs for TUMOR NECROSIS FACTOR-ALPHA.

tRNA Ligase [M0017245]

tRNA Methyltransferases [M0019215]
Enzymes that catalyze the S-adenosyl-L-methionine-dependent methylation of ribonucleotide bases within a transfer RNA molecule. EC 2.1.1.

Trofan [M0372553]

Tromasin [M0332353]

Trophic Factor Receptors [M0027149]

Tropocollagen [M0022037]
The molecular unit of collagen fibrils that consist of repeating three-stranded polypeptide units arranged head to tail in parallel bundles. It is a right-handed triple helix composed of 2 polypeptide chains. It is rich in glycine, proline, hydroxyproline, and hydroxylysine.

Tropoelastin [M0022038]
A salt-soluble precursor of elastin. Lysyl oxidase is instrumental in converting it to elastin in connective tissue.

Tropoelastin b [M0022039]

Tropomodulin [M0196541]
An actin capping protein that binds to the pointed-end of ACTIN. It functions in the presence of TROPOMYOSIN to inhibit microfilament elongation.

Tropomyosin [M0022045]
A protein found in the thin filaments of muscle fibers. It inhibits contraction of the muscle unless its position is modified by TROPONIN.

Tropomyosin Mg [M0022046]

Troponin [M0022048]
One of the minor protein components of skeletal muscle. Its function is to serve as the calcium-binding component in the troponin-tropomyosin B-actin-myosin complex by conferring calcium sensitivity to the cross-linked actin and myosin filaments.

Troponin C [M0028613]
One of the three polypeptide chains that make up the TROPONIN complex of skeletal muscle. It is a calcium-binding protein.

Troponin I [M0028614]
One of the three polypeptide chains that make up the TROPONIN complex. It inhibits F-actin-myosin interactions.

Troponin T [M0029843]
One of the three polypeptide chains that make up the TROPONIN complex. It is a cardiac-specific protein that binds to TROPOMYOSIN. It is released from damaged or injured heart muscle cells (MYOCYTES, CARDIAC). Defects in the gene encoding troponin T result in FAMILIAL HYPERTROPHIC CARDIOMYOPATHY.

Troponin T1 [M0029845]

Troponin T2 [M0029844]

TRP Channel [M0260716]

TRPC Cation Channels [M0472346]
A subgroup of TRP cation channels that contain 3-4 ANKYRIN repeats and a conserved C-terminal domain. Members are highly expressed in the CENTRAL NERVOUS SYSTEM. Selectivity for calcium over sodium ranges from 0.5 to 10.

TRPM Cation Channels [M0472347]
A subgroup of TRP cation channels named after melastatin protein. They have the TRP domain but lack ANKYRIN repeats. Enzyme domains in the C-terminus leads to them being called chanzymes.

TRPP Cation Channels [M0474795]
A subgroup of TRP cation channels that are widely expressed in various cell types. Defects are associated with POLYCYSTIC KIDNEY DISEASES.

TRPV Cation Channels [M0194000]
A subgroup of TRP cation channels named after vanilloid receptor. They are very sensitive to TEMPERATURE and hot spicy food and CAPSAICIN. They have the TRP domain and ANKYRIN repeats. Selectivity for CALCIUM over SODIUM ranges from 3 to 100 fold.

trs-art Gene Protein, HIV [M0024071]

Trypanosoma cruzi PEPCK [M0029327]

Trypsin [M0022078]
A serine endopeptidase that is formed from TRYPSINOGEN in the pancreas. It is converted into its active form by ENTEROPEPTIDASE in the small intestine. It catalyzes hydrolysis of the carboxyl group of either arginine or lysine. EC 3.4.21.4.

Trypsin Inhibitor, Bowman-Birk Soybean [M0022079]
A low-molecular-weight protein (minimum molecular weight 8000) which has the ability to inhibit trypsin as well as chymotrypsin at independent binding sites. It is characterized by a high cystine content and the absence of glycine.

Trypsin Inhibitor, Kazal Pancreatic [M0022080]
A pancreatic trypsin inhibitor common to all mammals. It is secreted with the zymogens into the pancreatic juice. It is a protein composed of 56 amino acid residues and is different in amino acid composition and physiological activity from the Kunitz bovine pancreatic trypsin inhibitor (APROTININ).

Trypsin Inhibitor, Kunitz Soybean [M0022083]
A high-molecular-weight protein (approximately 22,500) containing 198 amino acid residues. It is a strong inhibitor of trypsin and human plasmin.

Trypsinogen [M0022085]
The inactive proenzyme of trypsin secreted by the pancreas, activated in the duodenum via cleavage by enteropeptidase. (Stedman, 25th ed)

Trypsinogen 1 [M0022086]

Tryptacin [M0372552]

Tryptan [M0372551]

Tryptases [M0210462]
A family of neutral serine proteases with TRYPSIN-like activity. Tryptases are primarily found in the SECRETORY GRANULES of MAST CELLS and are released during mast cell degranulation.

Tryptophan [M0022088]
An essential amino acid that is necessary for normal growth in infants and for NITROGEN balance in adults. It is a precursor of INDOLE ALKALOIDS in plants. It is a precursor of SEROTONIN (hence its use as an antidepressant and sleep aid). It can be a precursor to NIACIN, albeit inefficiently, in mammals.

Tryptophan Hydroxylase [M0022090]
An enzyme that catalyzes the hydroxylation of TRYPTOPHAN to 5-HYDROXYTRYPTOPHAN in the presence of NADPH and molecular oxygen. It is important in the biosynthesis of SEROTONIN.

Tryptophan Oxygenase [M0022091]
A dioxygenase with specificity for the oxidation of the indoleamine ring of TRYPTOPHAN. It is a LIVER-specific enzyme that is the first and rate limiting enzyme in the kynurenine pathway of TRYPTOPHAN catabolism.

Tryptophan Synthase [M0022092]
An enzyme that catalyzes the conversion of L-serine and 1-(indol-3-yl)glycerol 3-phosphate to L-tryptophan and glyceraldehyde 3-phosphate. It is a pyridoxal phosphate protein that also catalyzes the conversion of serine and indole into tryptophan and water and of indoleglycerol phosphate into indole and glyceraldehyde phosphate. (From Enzyme Nomenclature, 1992) EC 4.2.1.20.

Tryptophan Transaminase [M0080194]
A PYRIDOXAL PHOSPHATE containing enzyme that catalyzes the transfer amino group from L-TRYPTOPHAN to 2-OXOGLUTARATE in order to generate indolepyruvate and L-GLUTAMATE.

Tryptophan-tRNA Ligase [M0022094]
An enzyme that activates tryptophan with its specific transfer RNA. EC 6.1.1.2.

Tryptophanase [M0022093]
An enzyme that catalyzes the conversion of L-tryptophan and water to indole, pyruvate, and ammonia. It is a pyridoxal-phosphate protein, requiring K+. It also catalyzes 2,3-elimination and beta-replacement reactions of some indole-substituted tryptophan analogs of L-cysteine, L-serine, and other 3-substituted amino acids. (From Enzyme Nomenclature, 1992) EC 4.1.99.1.

Trypure [M0332645]

Tubulin [M0022142]
A microtubule subunit protein found in large quantities in mammalian brain. It has also been isolated from sperm flagella, cilia, and other sources. Structurally, the protein is a dimer with a molecular weight of approximately 120,000 and a sedimentation coefficient of 5.8S. It binds to colchicine, vincristine, and vinblastine.

Tuftsin [M0022144]
N(2)-((1-(N(2)-L-Threonyl)-L-lysyl)-L-prolyl)-L-arginine. A tetrapeptide produced in the spleen by enzymatic cleavage of a leukophilic gamma-globulin. It stimulates the phagocytic activity of blood polymorphonuclear leukocytes and neutrophils in particular. The peptide is located in the Fd fragment of the gamma-globulin molecule.

Tumor Necrosis Factor Decoy Receptors [M0492599]
A subclass of tumor necrosis family receptors that lack cell signaling domains. They bind to specific TNF RECEPTOR LIGANDS and are believed to play a modulating role in the TNF signaling pathway. Some of the decoy receptors are products of distinct genes, while others are products of ALTERNATIVE SPLICING of the MRNA for the active receptor.

Tumor Necrosis Factor Ligand Superfamily Member 13 [M0492350]
A member of tumor necrosis factor superfamily found on MACROPHAGES; DENDRITIC CELLS and T-LYMPHOCYTES. It occurs as transmembrane protein that can be cleaved to release a secreted form that specifically binds to TRANSMEMBRANE ACTIVATOR AND CAML INTERACTOR PROTEIN; and B CELL MATURATION ANTIGEN.

Tumor Necrosis Factor Ligand Superfamily Member 14 [M0286287]
A member of tumor necrosis factor superfamily found on activated LYMPHOCYTES and MONOCYTES. It occurs as transmembrane protein that can be cleaved to release a secreted form that specifically binds to LYMPHOTOXIN BETA RECEPTOR and TUMOR NECROSIS FACTOR RECEPTOR SUPERFAMILY, MEMBER 14.

Tumor Necrosis Factor Ligand Superfamily Member 15 [M0492862]
A member of tumor necrosis factor superfamily found on ENDOTHELIAL CELLS that plays a role in the inhibition of endothelial cell growth and PHYSIOLOGIC ANGIOGENESIS.

Tumor Necrosis Factor Receptor-Associated Factors [M0460357]
A family of genetically conserved signal transducing proteins that bind directly to TUMOR NECROSIS FACTOR RECEPTORS.

Tumor Necrosis Factor Receptor-Associated Peptides and Proteins [M0460355]
Intracellular signaling peptides and proteins that bind directly or indirectly to the cytoplasmic portion of TUMOR NECROSIS FACTOR RECEPTORS.

Tumor Necrosis Factor Superfamily Ligands [M0460560]

Tumor Necrosis Factor-alpha [M0022150]
Serum glycoprotein produced by activated MACROPHAGES and other mammalian MONONUCLEAR LEUKOCYTES. It has necrotizing activity against tumor cell lines and increases ability to reject tumor transplants. Also known as TNF-alpha, it is only 30% homologous to TNF-beta (LYMPHOTOXIN), but they share TNF RECEPTORS.

Tumor Necrosis Factors [M0460559]
A family of proteins that were originally identified by their ability to cause NECROSIS of NEOPLASMS. Their necrotic effect on cells is mediated through TUMOR NECROSIS FACTOR RECEPTORS which induce APOPTOSIS.

Tumor Suppressor Protein p14ARF [M0255541]
A gene product of the p16 tumor suppressor gene (GENES, P16). It antagonizes the function of MDM2 PROTEIN (which regulates P53 TUMOR SUPPRESSOR PROTEIN by targeting it for degradation). p14ARF is produced from the beta mRNA transcript of the p16 gene. The other gene product, produced from the alternatively spliced alpha transcript, is CYCLIN-DEPENDENT KINASE INHIBITOR P16. Both p16 gene products have tumor suppressor functions.

Tumor Suppressor Protein p53 [M0024670]
Nuclear phosphoprotein encoded by the p53 gene (GENES, P53) whose normal function is to control CELL PROLIFERATION and APOPTOSIS. A mutant or absent p53 protein has been found in LEUKEMIA; OSTEOSARCOMA; LUNG CANCER; and COLORECTAL CANCER.

Tumor Suppressor Proteins [M0374857]
Proteins that are normally involved in holding cellular growth in check. Deficiencies or abnormalities in these proteins may lead to unregulated cell growth and tumor development.

Tumor-Associated Trypsin Inhibitor [M0022081]

Twist Transcription Factor [M0171774]
A basic helix-loop-helix transcription factor that was originally identified in DROSOPHILA as essential for proper gastrulation and MESODERM formation. It plays an important role in EMBRYONIC DEVELOPMENT and CELL DIFFERENTIATION of MUSCLE CELLS, and is found in a wide variety of organisms.

TYK2 Kinase [M0495106]
A Janus kinase subtype that is involved in signaling from a broad variety of CYTOKINE RECEPTORS. The TYK2 kinase is considered the founding member of the Janus Kinase family and was initially discovered as a signaling partner for the INTERFERON ALPHA-BETA RECEPTOR. The kinase has since been shown to signal from several INTERLEUKIN RECEPTORS.

Type A Monoamine Oxidase [M0014027]

Type I Insulin [M0011422]

Type I Polyketide Synthase [M0171392]

Type II Insulin [M0011423]

Type II Polyketide Beta-Ketoacyl Synthase [M0171393]

Type III Procollagen [M0017626]

Type IV Fish Antifreeze Proteins [M0355988]

Type VIII Procollagen [M0372057]

Tyrocidine [M0022198]
An antibiotic mixture produced by Bacillus brevis which may be separated into three components, tyrocidines A, B, and C. It is the major constituent (40-60 per cent) of tyrothricin, gramicidin accounting for the remaining 10-20 per cent active material. It is a topical antimicrobial agent, that is very toxic parenterally.

Tyroderm [M0373258]

Tyrosine [M0022203]
A non-essential amino acid. In animals it is synthesized from PHENYLALANINE. It is also the precursor of EPINEPHRINE; THYROID HORMONES; and melanin.

Tyrosine 3-Monooxygenase [M0022206]
An enzyme that catalyzes the conversion of L-tyrosine, tetrahydrobiopterin, and oxygen to 3,4-dihydroxy-L-phenylalanine, dihydrobiopterin, and water. EC 1.14.16.2.

Tyrosine Decarboxylase [M0022205]
A pyridoxal-phosphate protein that catalyzes the conversion of L-tyrosine to tyramine and carbon dioxide. The bacterial enzyme also acts on 3-hydroxytyrosine and, more slowly, on 3-hydroxyphenylalanine. (From Enzyme Nomenclature, 1992) EC 4.1.1.25.

Tyrosine Phenol-Lyase [M0022207]
An enzyme that catalyzes the cleavage of tyrosine to phenol, pyruvate, and ammonia. It is a pyridoxal phosphate protein. The enzyme also forms pyruvate from D-tyrosine, L-cysteine, S-methyl-L-cysteine, L-serine, and D-serine, although at a slower rate. EC 4.1.99.2.

Tyrosine Transaminase [M0022204]
An enzyme that catalyzes the conversion of L-TYROSINE and 2-oxoglutarate to 4-hydroxyphenylpyruvate and L-GLUTAMATE. It is a pyridoxal-phosphate protein. L-PHENYLALANINE is hydroxylated to L-tyrosine. The mitochondrial enzyme may be identical with ASPARTATE AMINOTRANSFERASES (EC 2.6.1.1.). Deficiency of this enzyme may cause type II Tyrosinemia (see TYROSINEMIAS). EC 2.6.1.5.

Tyrosine-tRNA Ligase [M0022208]
An enzyme that activates tyrosine with its specific transfer RNA. EC 6.1.1.1.

Tyrosur [M0477140]

Tyrothricin [M0022209]
A polypeptide antibiotic mixture obtained from Bacillus brevis. It consists of a mixture of three tyrocidines (60%) and several gramicidins (20%) and is very toxic to blood, liver, kidneys, meninges, and the olfactory apparatus. It is used topically.

U4 snRNP [M0026431]

U6 snRNP [M0026432]

Ubiquitin [M0369737]
A highly conserved 76-amino acid peptide universally found in eukaryotic cells that functions as a marker for intracellular PROTEIN TRANSPORT and degradation. Ubiquitin becomes activated through a series of complicated steps and forms an isopeptide bond to lysine residues of specific proteins within the cell. These "ubiquitinated" proteins can be recognized and degraded by proteosomes or be transported to specific compartments within the cell.

Ubiquitin C [M0375993]
A single protein comprised of tandem repeats of the UBIQUITIN 78-amino acid sequence. It is a product of the polyubiquitin gene which contains multiple copies of the ubiquitin coding sequence. Proteolytic processing of ubiquitin C results in the formation of individual ubiquitin molecules. This protein is distinct from POLYUBIQUITIN, which is a protein formed through isopeptide linkage of multiple ubiquitin species.

Ubiquitin Thiolesterase [M0116969]
A thioester hydrolase which acts on esters formed between thiols such as DITHIOTHREITOL or GLUTATHIONE and the C-terminal glycine residue of UBIQUITIN.

Ubiquitin, Human [M0329583]

Ubiquitin-Activating Enzymes [M0446165]
A class of enzymes that catalyzes the ATP-dependent formation of a thioester bond between itself and UBIQUITIN. It then transfers the activated ubiquitin to one of the UBIQUITIN-PROTEIN LIGASES.

Ubiquitin-Conjugating Enzymes [M0175386]
A class of enzymes that form a thioester bond to UBIQUITIN with the assistance of UBIQUITIN-ACTIVATING ENZYMES. They transfer ubiquitin to the LYSINE of a substrate protein with the assistance of UBIQUITIN-PROTEIN LIGASES.

Ubiquitin-Like Proteins [M0369740]

Ubiquitin-Protein Ligase Complexes [M0115796]
Complexes of enzymes that catalyze the covalent attachment of UBIQUITIN to other proteins by forming a peptide bond between the C-terminal GLYCINE of UBIQUITIN and the alpha-amino groups of LYSINE residues in the protein. The complexes play an important role in mediating the selective-degradation of short-lived and abnormal proteins. The complex of enzymes can be broken down into three components that involve activation of ubiquitin (UBIQUITIN-ACTIVATING ENZYMES), conjugation of ubiquitin to the ligase complex (UBIQUITIN-CONJUGATING ENZYMES), and ligation of ubiquitin to the substrate protein (UBIQUITIN-PROTEIN LIGASES).

Ubiquitin-Protein Ligases [M0446168]
A diverse class of enzymes that interact with UBIQUITIN-CONJUGATING ENZYMES and ubiquitination-specific protein substrates. Each member of this enzyme group has its own distinct specificity for a substrate and ubiquitin-conjugating enzyme. Ubiquitin-protein ligases exist as both monomeric proteins multiprotein complexes.

Ubiquitins [M0022212]
A family of proteins that are structurally-related to Ubiquitin. Ubiquitins and ubiquitin-like proteins participate in diverse cellular functions, such as protein degradation and HEAT-SHOCK RESPONSE, by conjugation to other proteins.

UCHL1 Antigens [M0026539]

UDP Reductase [M0019073]

UDP-Glucuronic Acid 3-O-beta-D-Galactosyl-D-Galactose Glucuronosyltransferase [M0022223]

UDPglucose 4-Epimerase [M0022349]
A necessary enzyme in the metabolism of galactose. It reversibly catalyzes the conversion of UDPglucose to UDPgalactose. NAD+ is an essential component for enzymatic activity. EC 5.1.3.2.

UDPglucose-Hexose-1-Phosphate Uridylyltransferase [M0010336]
An enzyme that catalyzes the transfer of UMP from UDPglucose to galactose 1-phosphate, forming UDPgalactose and glucose 1-phosphate. Deficiency in this enzyme is the major cause of GALACTOSEMIA. EC 2.7.7.12.

Ultralente Insulin [M0011439]

Ultrase [M0474986]

Unithroid [M0463519]

Upstream Stimulatory Factors [M0159344]
Ubiquitously expressed basic HELIX-LOOP-HELIX MOTIF transcription factors. They bind CANNTG sequences in the PROMOTERS of a variety of GENES involved in carbohydrate and lipid metabolism.

Uracil-DNA Glycosidase [M0080376]
An enzyme that catalyzes the HYDROLYSIS of the N-glycosidic bond between sugar phosphate backbone and URACIL residue during DNA synthesis.

Urate Oxidase [M0022307]
An enzyme that catalyzes the conversion of urate and unidentified products. It is a copper protein. The initial products decompose to form allantoin. EC 1.7.3.3.

Urdamycin Polyketide Synthase [M0171394]

Urease [M0022318]
An enzyme that catalyzes the conversion of urea and water to carbon dioxide and ammonia. EC 3.5.1.5.

Ureohydrolases [M0022321]

Uridine Diphosphate Glucose Dehydrogenase [M0022348]
An enzyme that catalyzes the oxidation of UDPglucose to UDPglucuronate in the presence of NAD+. EC 1.1.1.22.

Uridine Kinase [M0022356]
An enzyme that catalyzes the phosphorylation of uridine and cytidine to uridine 5'-phosphate and cytidine 5'-phosphate, respectively. ATP, dUTP, dGTP, and dATP are effective phosphate donors. EC 2.7.1.48.

Uridine Phosphorylase [M0022359]
An enzyme that catalyzes the transfer of ribose from uridine to orthophosphate, forming uracil and ribose 1-phosphate. EC 2.4.2.3.

Urinary Plasminogen Activator [M0022396]
A proteolytic enzyme that converts plasminogen to plasmin where the preferential cleavage is between arginine and valine. It was isolated originally from human urine, but is found in most tissues of most vertebrates. EC 3.4.21.73.

Urocanate Hydratase [M0022381]
An enzyme that catalyzes the conversion of 4,5-dihydro-4-oxo-5-imidazolepropanoate to urocanate and water. EC 4.2.1.49.

Urofollitropin [M0013388]
A protein extract of human menopausal urine in which LUTEINIZING HORMONE has been partially or completely removed. Urofollitropin represents FOLLICLE STIMULATING HORMONE from the urine. In highly purified preparations, LH and other urinary proteins are removed.

Uropontin [M0195574]
A urinary form of osteopontin.

Uroporphyrinogen Decarboxylase [M0022406]
An enzyme that catalyzes the decarboxylation of UROPORPHYRINOGEN III to coproporphyrinogen III by the conversion of four acetate groups to four methyl groups. It is the fifth enzyme in the 8-enzyme biosynthetic pathway of HEME. Several forms of cutaneous PORPHYRIAS are results of this enzyme deficiency as in PORPHYRIA CUTANEA TARDA; and HEPATOERYTHROPOIETIC PORPHYRIA.

Uroporphyrinogen III Synthetase [M0022407]
An enzyme that catalyzes the cyclization of hydroxymethylbilane to yield UROPORPHYRINOGEN III and water. It is the fourth enzyme in the 8-enzyme biosynthetic pathway of HEME, and is encoded by UROS gene. Mutations of UROS gene result in CONGENITAL ERYTHROPOIETIC PORPHYRIA.

Urotensins [M0022411]
Teleost hormones. A family of small peptides isolated from urophyses of bony fishes. They have many different physiological effects, including long-lasting hypotensive activity and have been proposed as antihypertensives. There are at least four different compounds: urotensin I, urotensin II, urotensin III, and urotensin IV.

Uterine-Tissue Plasminogen Activator [M0016995]

Uteroglobin [M0022436]
A protein fraction of pregnant uterine fluid which can induce and regulate blastocystic development. Blastokinin is thought to be similar or identical to uteroglobin. Presence in uterine fluid regulated by progesterone.

UTP-Glucose-1-Phosphate Uridylyltransferase [M0009355]
An enzyme that catalyzes the formation of UDPglucose from UTP plus glucose 1-phosphate. EC 2.7.7.9.

UTP-Hexose-1-Phosphate Uridylyltransferase [M0008942]
An enzyme that catalyzes the synthesis of UDPgalactose from UTP and galactose-1-phosphate. It is present in low levels in fetal and infant liver, but increases with age, thereby enabling galactosemic infants who survive to develop the capacity to metabolize galactose. EC 2.7.7.10.

Utrophin [M0194275]
An autosomally-encoded 376-kDa cytoskeletal protein that is similar in structure and function to DYSTROPHIN. It is a ubiquitously-expressed protein that plays a role in anchoring the CYTOSKELETON to the PLASMA MEMBRANE.

V14rho [M0182788]

Vaccines, Recombinant [M0022456]

Vaccines, Synthetic [M0022459]
Small synthetic peptides that mimic surface antigens of pathogens and are immunogenic, or vaccines manufactured with the aid of recombinant DNA techniques. The latter vaccines may also be whole viruses whose nucleic acids have been modified.

Vacuolar Proton-Translocating ATPases [M0374091]
Proton-translocating ATPases that are involved in acidification of a variety of intracellular compartments.

Valine [M0022497]
A branched-chain essential amino acid that has stimulant activity. It promotes muscle growth and tissue repair. It is a precursor in the penicillin biosynthetic pathway.

Valine Dehydrogenase (NADP+) [M0171245]
An amino acid oxidoreductase that catalyzes the oxidative hydroxylation of L-VALINE to 3-methyl-2-oxobutanoate and AMMONIA in the presence of NADP.

Valine Lipoamide Dehydrogenase [M0012556]

Valine-tRNA Ligase [M0022507]
An enzyme that activates valine with its specific transfer RNA. EC 6.1.1.9

Valinomycin [M0022498]
A cyclododecadepsipeptide ionophore antibiotic produced by Streptomyces fulvissimus and related to the enniatins. It is composed of 3 moles each of L-valine, D-alpha-hydroxyisovaleric acid, D-valine, and L-lactic acid linked alternately to form a 36-membered ring. (From Merck Index, 11th ed) Valinomycin is a potassium selective ionophore and is commonly used as a tool in biochemical studies.

Vanadium Nitrogenase [M0014905]

Vanco Azupharma [M0476498]

VANCO-cell [M0476499]

Vanco-saar [M0476500]

Vancocin [M0022519]

Vancomicina Abbott [M0476502]

Vancomicina Chiesi [M0476503]

Vancomicina Combino Phar [M0476504]

Vancomicina Norman [M0476505]

Vancomycin [M0022517]
Antibacterial obtained from Streptomyces orientalis. It is a glycopeptide related to RISTOCETIN that inhibits bacterial cell wall assembly and is toxic to kidneys and the inner ear.

Vancomycin Hexal [M0476508]

Vancomycin Hydrochloride [M0022518]

Vancomycin Phosphate (1:2) [M0329598]

Vancomycin Phosphate (1:2), Decahydrate [M0329599]

Vancomycin Sulfate [M0329597]

Vancomycin-ratiopharm [M0476507]

Vancomycine Dakota [M0476509]

Vaniqa [M0485299]

Variant Surface Glycoproteins, Trypanosoma [M0022522]
Glycoproteins attached to the surface coat of the trypanosome. Many of these glycoproteins show amino acid sequence diversity expressed as antigenic variations. This continuous development of antigenically distinct variants in the course of infection ensures that some trypanosomes always survive the development of immune response to propagate the infection.

Varidase [M0020579]

Vascular Cell Adhesion Molecule-1 [M0028388]
Cytokine-induced cell adhesion molecule present on activated endothelial cells, tissue macrophages, dendritic cells, bone marrow fibroblasts, myoblasts, and myotubes. It is important for the recruitment of leukocytes to sites of inflammation. (From Pigott & Power, The Adhesion Molecule FactsBook, 1993, p154)

Vascular Endothelial Growth Factor A [M0356369]
The original member of the family of endothelial cell growth factors referred to as VASCULAR ENDOTHELIAL GROWTH FACTORS. Vascular endothelial growth factor-A was originally isolated from tumor cells and referred to as "tumor angiogenesis factor" and "vascular permeability factor". Although expressed at high levels in certain tumor-derived cells it is produced by a wide variety of cell types. In addition to stimulating vascular growth and vascular permeability it may play a role in stimulating VASODILATION via NITRIC OXIDE-dependent pathways. Alternative splicing of the mRNA for vascular endothelial growth factor A results in several isoforms of the protein being produced.

Vascular Endothelial Growth Factor B [M0259370]
A vascular endothelial growth factor expressed in a variety of tissues. It binds with high specificity to VASCULAR ENDOTHELIAL GROWTH FACTOR RECEPTOR-1 and NEUROPILIN-1.

Vascular Endothelial Growth Factor C [M0260241]
A vascular endothelial growth factor that specifically binds to VASCULAR ENDOTHELIAL GROWTH FACTOR RECEPTOR-2 and VASCULAR ENDOTHELIAL GROWTH FACTOR RECEPTOR-3. In addition to being an angiogenic factor it can act on LYMPHATIC VESSELS to stimulate LYMPHANGIOGENESIS. It is similar in structure to VASCULAR ENDOTHELIAL GROWTH FACTOR D in that they both contain N- and C-terminal extensions that were not found in other VEGF family members.

Vascular Endothelial Growth Factor D [M0279673]
A vascular endothelial growth factor that specifically binds to VASCULAR ENDOTHELIAL GROWTH FACTOR RECEPTOR-2 and VASCULAR ENDOTHELIAL GROWTH FACTOR RECEPTOR-3. In addition to being an angiogenic factor it can act on LYMPHATIC VESSELS to stimulate LYMPHANGIOGENESIS. It is similar in structure to VASCULAR ENDOTHELIAL GROWTH FACTOR C in that they both contain N- and C-terminal extensions that were not found in other VEGF family members.

Vascular Endothelial Growth Factor Receptor-1 [M0175703]
A 180-kDa VEGF receptor found primarily in endothelial cells that is essential for vasculogenesis and vascular maintenance. It is also known as Flt-1 (fms-like tyrosine kinase receptor-1). A soluble, alternatively spliced isoform of the receptor may serve as a binding protein that regulates the availability of various ligands for VEGF receptor binding and signal transduction.

Vascular Endothelial Growth Factor Receptor-2 [M0185196]
A 200-230-kDa tyrosine kinase receptor for vascular endothelial growth factors found primarily in endothelial and hematopoietic cells and their precursors. VEGFR-2 is important for vascular and hematopoietic development, and mediates almost all endothelial cell responses to VEGF.

Vascular Endothelial Growth Factor Receptor-3 [M0202877]
A vascular endothelial cell growth factor receptor whose expression is restricted primarily to adult lymphatic endothelium. VEGFR-3 preferentially binds the vascular endothelial growth factor C and vascular endothelial growth factor D and may be involved in the control of lymphangiogenesis.

Vascular Endothelial Growth Factor, Endocrine-Gland-Derived [M0398985]
A vascular endothelial growth factor whose expression is found largely restricted to the GONADS; ADRENAL CORTEX; and PLACENTA. It has similar biological activity to VASCULAR ENDOTHELIAL GROWTH FACTOR-A.

Vascular Endothelial Growth Factors [M0057221]
A family of angiogenic proteins that are closely-related to VASCULAR ENDOTHELIAL GROWTH FACTOR A. They play an important role in the growth and differentiation of vascular as well as lymphatic endothelial cells.

Vasoactive Intestinal Peptide [M0022549]
A highly basic, 28 amino acid neuropeptide released from intestinal mucosa. It has a wide range of biological actions affecting the cardiovascular, gastrointestinal, and respiratory systems and is neuroprotective. It binds special receptors (RECEPTORS, VASOACTIVE INTESTINAL PEPTIDE).

Vasopressin (USP) [M0494241]
A pharmaceutical preparation containing a mixture of arg-vasopressin and lys-vasopressin. It is prepared by synthesis or obtained from neurohypophyseal extract of domestic animals. Its vasopressor activity is not less than 300 USP vasopressin units per mg.

Vasopressin Receptor 1 [M0119330]

Vasopressin V1a Receptor [M0119325]

Vasopressin V1b Receptor [M0119326]

Vasopressin V2 Receptor [M0026522]

Vasopressins [M0022562]
Antidiuretic hormones released by the NEUROHYPOPHYSIS of all vertebrates (structure varies with species) to regulate water balance and OSMOLARITY. In general, vasopressin is a nonapeptide consisting of a six-amino-acid ring with a cysteine 1 to cysteine 6 disulfide bridge or an octapeptide containing a CYSTINE. All mammals have arginine vasopressin except the pig with a lysine at position 8. Vasopressin, a vasoconstrictor, acts on the KIDNEY COLLECTING DUCTS to increase water reabsorption, increase blood volume and blood pressure.

Vasotec [M0363632]

Vasotocin [M0022564]
A nonapeptide that contains the ring of OXYTOCIN and the side chain of ARG-VASOPRESSIN with the latter determining the specific recognition of hormone receptors. Vasotocin is the non-mammalian vasopressin-like hormone or antidiuretic hormone regulating water and salt metabolism.

Vault Ribonucleoprotein Particles [M0030039]
Large cytoplasmic ribonucleoprotein particles that have an eight-fold symmetry with a central pore and petal-like structure giving the appearance of an octagonal dome. (The Dictionary of Cell Biology, Lackie and Dow, 2nd ed.)

VDJ Recombinases [M0448805]
Recombinases involved in the rearrangement of immunity-related GENES such as IMMUNOGLOBULIN GENES and T-CELL RECEPTOR GENES.

Vegetable Proteins [M0022575]
Proteins which are present in or isolated from vegetables or vegetable products used as food. The concept is distinguished from PLANT PROTEINS which refers to non-dietary proteins from plants.

Velosulin [M0011424]

Venacil [M0332983]

Venimmune [M0025527]

Venoglobulin [M0025528]

Venoglobulin-I [M0025529]

Venombin A [M0328362]
A thrombin-like enzyme from the venom of snakes of the viper/rattlesnake group. Species variants of the enzyme include ANCROD (Agkistrodon rhodostoma (Malayan pit viper)); BATROXOBIN from Bothrops atrox; and crotalase from Crotalus adamanteus (Eastern diamondback rattlesnake). EC 3.4.21.74.

Ventricular alpha, beta- Myosin [M0371572]
A form of ventricular myosin that contains one alpha-myosin heavy chain and one beta-myosin heavy chain. It has an ATPase activity and contraction rate that is intermediate between ventricular alpha-myosin and ventricular beta-myosin.

Ventricular alpha-Myosin [M0014360]
A form of ventricular myosin that contains two alpha-myosin heavy chains. It has a higher ATPase activity and contracts at a faster rate than myosins containing beta-myosin heavy chains.

Ventricular beta-Myosin [M0023672]
A form of ventricular myosin that contains two beta-myosin heavy chains. It has a lower ATPase activity and contracts at a slower rate than myosins containing alpha-myosin heavy chains.

Ventricular Myosins [M0371571]
Isoforms of MYOSIN TYPE II, specifically found in the ventricular muscle of the HEART. Defects in the genes encoding ventricular myosins result in FAMILIAL HYPERTROPHIC CARDIOMYOPATHY.

Ventricular Natriuretic Peptide, B-type [M0215929]

Vernamycin B [M0022746]
An antibiotic mixture originally isolated from Streptomyces loidensis. It contains a mixture of compounds belonging to STREPTOGRAMIN GROUP A and STREPTOGRAMIN GROUP B.

Versicans [M0171368]
HYALURONAN-containing proteoglycans found in the EXTRACELLULAR MATRIX of a variety of tissues and organs. Several versican isoforms exist due to multiple ALTERNATIVE SPLICING.

Vesicle SNARE Proteins [M0472313]

Vesicle-Associated Membrane Protein 1 [M0157865]
A member of the vesicle-associated membrane protein family involved in the MEMBRANE FUSION of TRANSPORT VESICLES to their target membrane.

Vesicle-Associated Membrane Protein 2 [M0157866]
A synaptic membrane protein involved in MEMBRANE FUSION of SYNAPTIC VESICLES with the presynaptic membranes. It is the prototype member of the R-SNARE PROTEINS.

Vesicle-Associated Membrane Protein 3 [M0219041]
A member of the vesicle associated membrane protein family. It has a broad tissue distribution and is involved in MEMBRANE FUSION events of the endocytic pathways.

Vesicle-Associated Membrane Proteins [M0157867]

Vesicular Acetylcholine Transport Proteins [M0475622]
Vesicular amine transporter proteins that transport the neurotransmitter ACETYLCHOLINE into small SECRETORY VESICLES. Proteins of this family contain 12 transmembrane domains and exchange vesicular PROTONS for cytoplasmic acetylcholine.

Vesicular Biogenic Amine Transport Proteins [M0475619]
Integral membrane proteins of the LIPID BILAYER of SECRETORY VESICLES that catalyze transport and storage of biogenic amine NEUROTRANSMITTERS such as ACETYLCHOLINE; SEROTONIN; MELATONIN; HISTAMINE; and CATECHOLAMINES. The transporters exchange vesicular protons for cytoplasmic neurotransmitters.

Vesicular Glutamate Transport Protein 1 [M0397464]
A vesicular glutamate transporter protein that is predominately expressed in TELENCEPHALON of the BRAIN.

Vesicular Glutamate Transport Protein 2 [M0397465]
A vesicular glutamate transporter protein that is predominately expressed in the DIENCEPHALON and lower brainstem regions of the CENTRAL NERVOUS SYSTEM.

Vesicular Glutamate Transport Proteins [M0475624]
A family of vesicular neurotransmitter transporter proteins that were originally characterized as sodium dependent inorganic phosphate cotransporters. Vesicular glutamate transport proteins sequester the excitatory neurotransmitter GLUTAMATE from the CYTOPLASM into SECRETORY VESICLES in exchange for lumenal PROTONS.

Vesicular Inhibitory Amino Acid Transport Proteins [M0475623]
A family of vesicular neurotransmitter transporter proteins that sequester the inhibitory neurotransmitters GLYCINE; GAMMA-AMINOBUTYRIC ACID; and possibly GAMMA-HYDROXYBUTYRATE into SECRETORY VESICLES.

Vesicular Monoamine Transport Proteins [M0475621]
A family of vesicular amine transporter proteins that catalyze the transport and storage of CATECHOLAMINES and indolamines into SECRETORY VESICLES.

Vesicular Monoamine Transporter 1 [M0207698]

Vesicular Monoamine Transporter 2 [M0207699]

Vesicular Neurotransmitter Transport Proteins [M0475595]
A family of neurotransmitter transporter proteins that are INTEGRAL MEMBRANE PROTEINS of the LIPID BILAYER of SECRETORY VESICLES. They are ANTIPORTERS that exchange vesicular PROTONS for cytoplasmic NEUROTRANSMITTER and play an essential role in regulating neurotransmission.

Vesicular Transport Proteins [M0404369]
A broad category of proteins involved in the formation, transport and dissolution of TRANSPORT VESICLES. They play a role in the intracellular transport of molecules contained within membrane vesicles. Vesicular transport proteins are distinguished from MEMBRANE TRANSPORT PROTEINS, which move molecules across membranes, by the mode in which the molecules are transported.

Vestin [M0373241]

Vigabatrin [M0328364]
An analogue of GAMMA-AMINOBUTYRIC ACID. It is an irreversible inhibitor of 4-AMINOBUTYRATE TRANSAMINASE, the enzyme responsible for the catabolism of GAMMA-AMINOBUTYRIC ACID. (From Martindale The Extra Pharmacopoeia, 31st ed)

Vimentin [M0022670]
An intermediate filament protein found in most differentiating cells, in cells grown in tissue culture, and in certain fully differentiated cells. Its insolubility suggests that it serves a structural function in the cytoplasm. MW 52,000.

Vinactane [M0373267]

Vinculin [M0025312]
A cytoskeletal protein associated with cell-cell and cell-matrix interactions. The amino acid sequence of human vinculin has been determined. The protein consists of 1066 amino acid residues and its gene has been assigned to chromosome 10.

Viocin [M0373266]

Viokase [M0045747]

Viomycin [M0022690]
A strongly basic peptide, antibiotic complex from several strains of Streptomyces. It is allergenic and toxic to kidneys and the labyrinth. Viomycin is used in tuberculosis as several different salts and in combination with other agents.

Viomycins [M0022691]

Viral Core Proteins [M0022705]
Proteins found mainly in icosahedral DNA and RNA viruses. They consist of proteins directly associated with the nucleic acid inside the NUCLEOCAPSID.

Viral Envelope Glycoprotein gp55 (Friend Virus) [M0022715]

Viral Envelope Glycoprotein gPr90 (Murine Leukemia Virus) [M0022716]

Viral Envelope Proteins [M0022717]
Layers of protein which surround the capsid in animal viruses with tubular nucleocapsids. The envelope consists of an inner layer of lipids and virus specified proteins also called membrane or matrix proteins. The outer layer consists of one or more types of morphological subunits called peplomers which project from the viral envelope; this layer always consists of glycoproteins.

Viral Envelope Proteins E1 [M0022718]

Viral Envelope Proteins E2 [M0022719]

Viral Envelope Proteins gp52 [M0022720]

Viral Envelope Proteins gp70 [M0022721]

Viral Fusion Glycoproteins [M0022729]

Viral Fusion Proteins [M0022730]
Proteins, usually glycoproteins, found in the viral envelopes of a variety of viruses. They promote cell membrane fusion and thereby may function in the uptake of the virus by cells.

Viral M Protein [M0022736]

Viral Matrix Proteins [M0022735]
Proteins associated with the inner surface of the lipid bilayer of the viral envelope. These proteins have been implicated in control of viral transcription and may possibly serve as the "glue" that binds the nucleocapsid to the appropriate membrane site during viral budding from the host cell.

Viral N Protein [M0029091]

Viral Nonstructural Proteins [M0026358]
Proteins encoded by a VIRAL GENOME that are produced in the organisms they infect, but not packaged into the VIRUS PARTICLES. Some of these proteins may play roles within the infected cell during VIRUS REPLICATION or act in regulation of virus replication or VIRUS ASSEMBLY.

Viral Nonstructural Proteins NS1 [M0026359]

Viral Nonstructural Proteins NS2 [M0026361]

Viral Protein A, HIV [M0024986]

Viral Protein P19 [M0022703]

Viral Protein Q, HIV [M0024987]

Viral Proteins [M0022737]
Proteins found in any species of virus.

Viral Regulatory Proteins [M0023880]
Proteins which regulate the rate of transcription of viral structural genes.

Viral Structural Proteins [M0024034]
Viral proteins that are components of the mature assembled VIRUS PARTICLES. They may include nucleocapsid core proteins (gag proteins), enzymes packaged within the virus particle (pol proteins), and membrane components (env proteins). These do not include the proteins encoded in the VIRAL GENOME that are produced in infected cells but which are not packaged in the mature virus particle,i.e. the so called non-structural proteins (VIRAL NONSTRUCTURAL PROTEINS.)

Viral Structural Proteins VP [M0024035]

Viral Tail Proteins [M0026390]
Proteins found in the tail sections of DNA and RNA viruses. It is believed that these proteins play a role in directing chain folding and assembly of polypeptide chains.

Virginiamycin [M0022742]
A cyclic polypeptide antibiotic complex from Streptomyces virginiae, S. loidensis, S. mitakaensis, S. pristina-spiralis, S. ostreogriseus, and others. It consists of 2 major components, VIRGINIAMYCIN FACTOR M1 and virginiamycin Factor S1. It is used to treat infections with gram-positive organisms and as a growth promoter in cattle, swine, and poultry.

Virosomes [M0358923]
Semi-synthetic complex derived from nucleic-acid free viral particles. They are essentially reconstituted viral coats, where the infectious nucleocapsid is replaced by a compound of choice. Virosomes retain their fusogenic activity and thus deliver the incorporated compound (antigens, drugs, genes) inside the target cell. They can be used for vaccines (VACCINES, VIROSOME), drug delivery, or gene transfer.

Virus Peplomer Proteins [M0022722]

Vitamin B 12 Binder [M0021784]

Vitamin B12-Dependent Methionine Synthase [M0021237]

Vitamin B12-Independent Methionine Synthase [M0021238]

Vitamin D-Binding Protein [M0022799]
An alpha-globulin found in the plasma of man and other vertebrates. It is apparently synthesized in the liver and carries vitamin D and its metabolites through the circulation and mediates the response of tissue. It is also known as group-specific component (Gc). Gc subtypes are used to determine specific phenotypes and gene frequencies. These data are employed in the classification of population groups, paternity investigations, and in forensic medicine.

Vitamin K Reductase [M0025390]

Vitamin U [M0022809]
A vitamin found in green vegetables. It is used in the treatment of peptic ulcers, colitis, and gastritis and has an effect on secretory, acid-forming, and enzymatic functions of the intestinal tract.

Vitellins [M0007125]
Major egg yolk proteins from egg-laying animals such as non-mammalian VERTEBRATES; ARTHROPODS; and others. They are high-density lipoglycoproteins derived from circulating precursors, VITELLOGENINS. Vitellins serve as nutrients for the growing non-mammalian embryos (EMBRYO, NONMAMMALIAN).

Vitellogenin II [M0022817]

Vitellogenins [M0022816]
Phospholipoglycoproteins produced in the fat body of egg-laying animals such as non-mammalian VERTEBRATES; ARTHROPODS; and others. Vitellogenins are secreted into the HEMOLYMPH, and taken into the OOCYTES by receptor-mediated ENDOCYTOSIS to form the major yolk proteins, VITELLINS. Vitellogenin production is under the regulation of steroid hormones, such as ESTRADIOL and JUVENILE HORMONES in insects.

Vitronectin [M0028506]
A blood plasma glycoprotein that mediates cell adhesion and interacts with proteins of the complement, coagulation, and fibrinolytic cascade. (From Segen, Dictionary of Modern Medicine, 1992)

Voltage-Dependent Anion Channel 1 [M0134830]
Voltage-dependent anion channel 1 is the major pore-forming protein of the mitochondrial outer membrane. It also functions as a ferricyanide reductase in the PLASMA MEMBRANE.

Voltage-Dependent Anion Channel 2 [M0134831]
Voltage-dependent anion channel 2 is a low abundance mammalian isoform of VDAC that interacts with the inactive form of BAK PROTEIN.

Voltage-Dependent Anion Channels [M0472147]
A family of voltage-gated eukaryotic porins that form aqueous channels. They play an essential role in mitochondrial CELL MEMBRANE PERMEABILITY, are often regulated by BCL-2 PROTO-ONCOGENE PROTEINS, and have been implicated in APOPTOSIS.

Von Hippel-Lindau Tumor Suppressor Protein [M0481855]
A ubiquitin-protein ligase that mediates OXYGEN-dependent polyubiquitination of HYPOXIA-INDUCIBLE FACTOR 1, ALPHA SUBUNIT. It is inactivated in VON HIPPEL-LINDAU SYNDROME.

von Willebrand Factor [M0022850]
A high-molecular-weight plasma protein, produced by endothelial cells and megakaryocytes, that is part of the factor VIII/von Willebrand factor complex. The von Willebrand factor has receptors for collagen, platelets, and ristocetin activity as well as the immunologically distinct antigenic determinants. It functions in adhesion of platelets to collagen and hemostatic plug formation. The prolonged bleeding time in von Willebrand's disease is due to the deficiency of this factor.

von Willebrand Factor Type IIB [M0022851]

VP(1) [M0024036]

VP(2) [M0024037]

VP(3) [M0024038]

VP(6) [M0024039]

VP(7) [M0024040]

Vps34 Phosphatidylinositol 3-Kinase [M0029503]

vpu Protein [M0024975]

VSG 117 [M0022523]

VSG 118 [M0022524]

VSG 221 [M0022525]

WASP-Family Verprolin Homologous Proteins [M0481814]

Water-Splitting Enzyme of Photosynthesis [M0080433]

WdPKS1 Protein [M0353930]

Wegener Autoantigen [M0491650]
Human myeloblastin that is the antigen involved in the autoimmune disorder WEGENER GRANULOMATOSIS.

Wellferon [M0025712]

Wheat Germ Agglutinin-Horseradish Peroxidase Conjugate [M0028372]
The lectin wheatgerm agglutinin conjugated to the enzyme HORSERADISH PEROXIDASE. It is widely used for tracing neural pathways.

WhiE Polyketide Synthase [M0171395]

Winged-Helix Transcription Factors [M0480916]
A subfamily of HELIX-TURN-HELIX DNA-binding proteins that contain a variable length loop adjacent to the HTH motif. The loop connects two anti-parallel strands and forms a wing when bound to DNA.

Wiskott-Aldrich Syndrome Protein [M0235436]
WASP protein is mutated in WISKOTT-ALDRICH SYNDROME and is expressed primarily in hematopoietic cells. It is the founding member of the WASP protein family and interacts with CDC42 PROTEIN to help regulate ACTIN polymerization.

Wiskott-Aldrich Syndrome Protein Family [M0480078]
A family of microfilament proteins whose name derives from the fact that mutations in members of this protein family have been associated with WISKOTT-ALDRICH SYNDROME. They are involved in ACTIN polymerization and contain a polyproline-rich region that binds to PROFILIN, and a verprolin homology domain that binds G-ACTIN.

Wiskott-Aldrich Syndrome Protein Family, Member 1 [M0301786]

Wiskott-Aldrich Syndrome Protein Family, Member 2 [M0480129]

Wiskott-Aldrich Syndrome Protein Family, Member 3 [M0480130]

Wiskott-Aldrich Syndrome Protein, Neuronal [M0267544]
A member of the Wiskott-Aldrich syndrome protein family that is found at high levels in NERVE CELLS. It interacts with GRB2 ADAPTOR PROTEIN and with CDC42 PROTEIN.

Wnt Proteins [M0151350]
Wnt proteins are a large family of secreted glycoproteins that play essential roles in EMBRYONIC AND FETAL DEVELOPMENT, and tissue maintenance. They bind to FRIZZLED RECEPTORS and act as PARACRINE PROTEIN FACTORS to initiate a variety of SIGNAL TRANSDUCTION PATHWAYS. The canonical Wnt signaling pathway stabilizes the transcriptional coactivator BETA CATENIN.

Wnt1 Protein [M0151359]
A proto-oncogene protein and member of the Wnt family of proteins. It is expressed in the caudal MIDBRAIN and is essential for proper development of the entire mid-/hindbrain region.

Wnt2 Protein [M0468931]
A proto-oncogene protein and member of the Wnt family of proteins. It is frequently up-regulated in human GASTRIC CANCER and is a tumor marker (TUMOR MARKERS, BIOLOGICAL) of gastric and COLORECTAL CANCER.

WT1 Proteins [M0193890]
Isoforms encoded by the WT1 Wilms tumor suppressor gene (GENES, WILMS TUMOR) and produced by alternative splicings. They are zinc finger-containing transcription factors involved in both transactivation and repression, and are critical for normal development and function of the urogenital tract.

Wy-42462 [M0373921]

Wydase [M0373020]

X-Linked Inhibitor of Apoptosis Protein [M0261895]
An inhibitor of apoptosis protein that is translated by a rare cap-independent mechanism. It blocks caspase-mediated cellular destruction by inhibiting CASPASE 3; CASPASE 7; and CASPASE 9.

Xanef [M0485300]

Xanthine Dehydrogenase [M0023044]
An enzyme that catalyzes the oxidation of xanthine in the presence of NAD+ to form urate and NADH. It acts also on a variety of other purines and aldehydes. EC 1.1.1.204.

Xanthine Oxidase [M0023045]
An iron-molybdenum flavoprotein containing FLAVIN-ADENINE DINUCLEOTIDE that oxidizes hypoxanthine, some other purines and pterins, and aldehydes. Deficiency of the enzyme, an autosomal recessive trait, causes xanthinuria. EC 1.1.3.22.

Xedar Receptor [M0492713]
An ectodysplasin receptor subtype that is specific for ECTODYSPLASIN A2. Unlike the EDAR RECEPTOR the Xedar receptor signals through direct association with TNF RECEPTOR-ASSOCIATED FACTORS. The protein name derives from the fact that gene that encodes it resides on the X CHROMOSOME.

Xenobiotic Monooxygenases [M0417290]
Monooxygenases that oxidize exogenous substrates.

Xenopus laevis Proteins [M0385444]

Xenopus Proteins [M0385443]
Proteins obtained from various species of Xenopus. Included here are proteins from the African clawed frog (XENOPUS LAEVIS). Many of these proteins have been the subject of scientific investigations in the area of MORPHOGENESIS and development.

Xeroderma Pigmentosum Group A Protein [M0182049]
A ZINC FINGER MOTIF protein that recognizes and interacts with damaged DNA. It is a DNA-binding protein that plays an essential role in NUCLEOTIDE EXCISION REPAIR. Mutations in this protein are associated with the most severe form of XERODERMA PIGMENTOSUM.

Xeroderma Pigmentosum Group D Protein [M0201753]
A DNA helicase that is a component of TRANSCRIPTION FACTOR TFIIH. It plays an essential role in NUCLEOTIDE EXCISION REPAIR, and mutations in this protein are associated with XERODERMA PIGMENTOSUM.

XR78E-F protein [M0196518]

Xylan Endo-1,3-beta-Xylosidase [M0073459]
A xylosidase that catalyses the random hydrolysis of 1,3-beta-D-xylosidic linkages in 1,3-beta-D-xylans.

Xylanase A [M0446649]

Xylanase B [M0175642]

Xylanase C [M0195124]

Xylanase D [M0216568]

Xylanase J [M0446916]

Xylanase Y [M0446919]

Xylanase Z [M0446915]

Xylose Reductase [M0000685]

Xylosidases [M0023077]
A group of enzymes that catalyze the hydrolysis of alpha- or beta-xylosidic linkages. EC 3.2.1.8 catalyzes the endo-hydrolysis of 1,4-beta-D-xylosidic linkages; EC 3.2.1.32 catalyzes the endo-hydrolysis of 1,3-beta-D-xylosidic linkages; EC 3.2.1.37 catalyzes the exo-hydrolysis of 1,4-beta-D-linkages from the non-reducing termini of xylans; and EC 3.2.1.72 catalyzes the exo-hydrolysis of 1,3-beta-D-linkages from the non-reducing termini of xylans. Other xylosidases have been identified that catalyze the hydrolysis of alpha-xylosidic bonds.

Y-Box-Binding Protein 1 [M0124261]
Y-box-binding protein 1 was originally identified as a DNA-binding protein that interacts with Y-box PROMOTER REGIONS of MHC CLASS II GENES. It is a highly conserved transcription factor that regulates expression of a wide variety of GENES.

Yb-Glutathione-S-Transferase [M0009403]

Yeast Alcohol Dehydrogenase [M0000646]

Yeast Proteins [M0385154]

Yolk Proteins [M0007124]

Yolk Proteins, Dietary [M0023710]

YY1 Transcription Factor [M0324228]
A ubiquitously expressed zinc finger-containing protein that acts both as a repressor and activator of transcription. It interacts with key regulatory proteins such as TATA-BINDING PROTEIN; TFIIB; and ADENOVIRUS E1A PROTEINS.

ZAP-70 Protein-Tyrosine Kinase [M0209216]
A protein tyrosine kinase that is required for T-CELL development and T-CELL ANTIGEN RECEPTOR function.

Zebrafish Proteins [M0385517]
Proteins obtained from the ZEBRAFISH. Many of the proteins in this species have been the subject of studies involving basic embryological development (EMBRYOLOGY).

Zein [M0023123]
A protein obtainable from corn. It has a molecular weight of about 40,000. It does not contain tryptophan or lysine. (Dorland, 28th ed)

Zemaira [M0462993]

Zestril [M0026772]

zeta-Crystallins [M0005398]
A group of crystallins that have been found in the lens (LENS, CRYSTALLINE) of certain species of VERTEBRATES including GUINEA PIGS; CAMELS; and LLAMAS. They are inactivated forms of NAD(P)H DEHYDROGENASE (QUINONE).

zeta-Globin [M0009290]

Zinc Chelatase [M0008357]

Zinc Cysteinate [M0005540]

Zinc Pantothenate [M0015825]

Zoladex [M0026218]

Zomacton [M0475572]

Zyderm [M0369419]

Zymase [M0474987]

Zymofren [M0011916]

Amino Acid, Peptide, or Protein

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