| alpha helix | <molecular biology> A particular helical folding of the polypeptide backbone in protein molecules (both fibrous and globular), in which the carbonyl oxygens are all hydrogen bonded to amide nitrogen atoms three residues along the chain. The translation of amino acid residues along the long axis is 0.15 nm and the rotation per residue, 100 |
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| alpha-hydroxyethylthiamin pyrophosphate | The activated form of acetaldehyde that is formed during the decarboxylation of active pyruvate. Formed in alcohol fermentation and in carbohydrate metabolism. Synonym: a-hydroxyethylthiamin pyrophosphate. (05 Mar 2000) |
| alpha-hydroxyglycine amidating dealkylase | <enzyme> From bovine neurointermediate pituitary; catalyses the conversion of alpha-hydroxybenzoylglycine to benzamide and glycolytic acid Registry number: EC 1.14.99.- Synonym: hgad-ase (26 Jun 1999) |
| alpha interferon | <cytokine> Interferon which is released by leukocytes in response to a viral infection. A protein cytokine that is used as an anticancer agent. (15 Nov 1997) |
| alpha-keto acid dehydrogenase | See: alpha-keto acid dehydrogenase. Anaerobic dehydrogenase, an enzyme (usually a pyridinoenzyme) catalyzing the transfer of hydrogen from some metabolite to some acceptor molecule (e.g., NAD+, cytochrome) other than oxygen; e.g., lactate dehydrogenase's, isocitrate dehydrogenase's, and others in EC class 1, excluding those listed under aerobic dehydrogenase. (05 Mar 2000) |
| alpha-keto acid dehydrogenase complex | See: alpha-keto acid dehydrogenase. Anaerobic dehydrogenase, an enzyme (usually a pyridinoenzyme) catalyzing the transfer of hydrogen from some metabolite to some acceptor molecule (e.g., NAD+, cytochrome) other than oxygen; e.g., lactate dehydrogenase's, isocitrate dehydrogenase's, and others in EC class 1, excluding those listed under aerobic dehydrogenase. (05 Mar 2000) |
| alpha-ketoadipate dehydrogenase | <enzyme> X-ketoadipic acid + nad + CoA yields glutaryl-CoA + co(2) + NADH + h Registry number: EC 1.2.1.- (26 Jun 1999) |
| alpha-ketoarginine decarboxylase | <enzyme> Alpha-ketoarginine gives gamma-guanidinobutyraldehyde Registry number: EC 4.1.1.- Synonym: alpha keto-arginine decarboxylase (26 Jun 1999) |
| alpha-ketobutyrate dehydrogenase | <enzyme> Rat liver enzyme oxidatively decarboxylates alpha-ketobutyrate to carbon dioxide and propionyl CoA; requires nad, fad and thiamine pyrophosphate Registry number: EC 1.2.1.- (26 Jun 1999) |
| alpha-ketodecarboxylase | Formerly, the enzyme system converting pyruvate (a 2-oxoacid) to acetyl-CoA and CO2, with reduction of NAD+ to NADH and the participation of lipoamide and thiamin pyrophosphate; now known to involve at least three enzymes in succession: pyruvate dehydrogenase, dihydrolipoamide acetyltransferase, and dihydrolipoamide dehydrogenase. Compare: pyruvate dehydrogenase (lipoamide). (05 Mar 2000) |
| alpha-ketoglutaramic acid | H2N-COCH2CH2COCOOH;a metabolite of glutamine formed by the action of glutamine aminotransferase; elevated in certain cases of hepatocoma. Synonym: 2-oxoglutaric acid. (05 Mar 2000) |
| alpha-ketoglutarate | A salt or ester of alpha-ketoglutaric acid. Alpha-ketoglutarate dehydrogenase, an enzyme that catalyses the oxidative decarboxylation of 2-ketoglutaric acid to succinyldihydrolipoate; the succinyl group is later transferred to CoA and the reduced lipoate is oxidised by NAD+; a complex that is a part of the tricarboxylic acid cycle. Synonym: 2-oxoglutarate dehydrogenase, alpha-ketoglutarate dehydrogenase complex. (05 Mar 2000) |
| alpha-ketoglutarate dehydrogenase complex | alpha-ketoglutarate dehydrogenase |
| alpha-ketoglutarate permease | <chemical> From E coli; 432-amino acid protein; amino acid sequence given in first source Synonym: kGTP gene product, wita protein, alpha-ketoglutarate transporter (26 Jun 1999) |
| alpha-ketoisocaproate oxygenase | <enzyme> From rat liver cytosol; oxidatively decarboxylates and hydroxylates alpha-ketoisocaporate to form beta-hydroxyisovalerate; requires fe(2+) and thiol; activated by ascorbate Registry number: EC 1.13.11.- Synonym: 2-ketoisocaproate oxygenase, alpha-ketoisocaproate dioxygenase (26 Jun 1999) |