| ordered on-random off mechanism | A scheme for substrate binding and product release for multisubstrate enzymes; for a two-substrate two-product enzyme with this mechanism, the individuals have to bind to the enzyme in a distinct order; however, once the products are formed they may dissociate from the enzyme in either order. It has been suggested that pyruvate kinase has such a mechanism. The random on-ordered off mechanism is simply the reverse of this mechanism. (05 Mar 2000) |
|---|---|
| A chain | A polypeptide component of insulin containing 21 amino acyl residues, beginning with a glycyl residue (NH2-terminus); insulin is formed by the linkage of an A chain to a B chain by two disulfide bonds; the amino-acid composition of the A chain is a function of species. Synonym: glycyl chain. In general, one of the polypeptides in a multiprotein complex. (05 Mar 2000) |
| alpha chain disease | A vague or indefinite term; could be used for alpha-heavy-chain disease (a lymphoplasma cell proliferative disease usually seen in Mediterranean men, characterised by intestinal involvement with steatorrhoea, often progressive with fatal outcome) or a thalassaemia (a genetic abnormality in the alpha globin chain of haemoglobin). (05 Mar 2000) |
| amino acids, branched-chain | Amino acids which have a branched carbon chain. (12 Dec 1998) |
| B chain | A polypeptide component of insulin containing 30 amino acyl residues, beginning with a phenylalanyl residue (NH2-terminus); insulin is formed by the linkage of a B chain to an A chain by two disulfide bonds; the amino-acid composition of the B chain is a function of species. Synonym: phenylalanyl chain. (05 Mar 2000) |
| behaviour chain | Related behaviours in a series in which each response serves as a stimulus for the next response. (05 Mar 2000) |
| branched chain acyl-CoA oxidase | <enzyme> Enzyme from human liver peroxisomes acts on both 2-methyl branched fatty acyl- and bile acid-CoA intermediates, unlike rat liver peroxisomes which have separate enzymes for branched chain fatty acids (pristanoyl-CoA) and bile acid-CoA; involved in beta-oxidation of fatty acids and bil Registry number: EC 1.3.3.- Synonym: 2-methyl-branched chain acyl-CoA oxidase, hbrcacox (26 Jun 1999) |
| branched-chain fatty-acid-kinase | <enzyme> From anaerobic spirochete ma-2 Registry number: EC 2.7.2.14 Synonym: isovalerate kinase, 2-methylbutyrate kinase, isobutyrate kinase (26 Jun 1999) |
| branched-chain fatty acid synthetase | <enzyme> Analogous to fatty acid synthetase complex but starting with a branched chain keto acid; from bacillis subtilis Registry number: EC 2.3.1.- Synonym: bcfa synthetase (26 Jun 1999) |
| branched chain ketoaciduria | Hereditary disease due to deficiency of an enzyme involved in amino acid metabolism, characterised by urine that smells like maple syrup. (12 Dec 1998) |
| branched chain ketonuria | Hereditary disease due to deficiency of an enzyme involved in amino acid metabolism, characterised by urine that smells like maple syrup. (12 Dec 1998) |
| gene rearrangement, alpha-chain T-cell antigen receptor | Ordered rearrangement of T-cell variable gene regions coding for the alpha-chain of antigen receptors. (12 Dec 1998) |
| gene rearrangement, beta-chain T-cell antigen receptor | Ordered rearrangement of T-cell variable gene regions coding for the beta-chain of antigen receptors. (12 Dec 1998) |
| gene rearrangement, b-lymphocyte, heavy chain | Ordered rearrangement of b-lymphocyte variable gene regions thereby contributing to antibody diversity. It occurs during the first stage of differentiation of the immature b-lymphocyte. (12 Dec 1998) |
| gene rearrangement, b-lymphocyte, light chain | Ordered rearrangement of b-lymphocyte variable gene regions coding for the kappa or lambda light chains, thereby contributing to antibody diversity. It occurs during the second stage of differentiation of the immature b-lymphocyte. (12 Dec 1998) |