| supplement | Something that supplies a want or make an addition: something that completes, adds a finishing touch or brings closer to completion or a desired state. (18 Nov 1997) |
|---|---|
| alpha-aminoadipyl-cysteinyl-valine synthetase | <enzyme> As of 9/27/95 this has been separated from isopenicillin n synthetase Registry number: EC 6.3.2.- Synonym: acv synthetase, aa-cysteine synthetase, delta-(alpha-aminoadipyl)-cys-val synthetase, delta-(l-alpha-aminoadipyl)-l-cyteinyl-d-valine synthetase, pcbab gene product, acva gene product (26 Jun 1999) |
| valine | <amino acid> An essential amino acid. Valine is found in abundant quantities in most food. Valine has a stimulant effect. Healthy growth depends on it. A deficiency results in a negative hydrogen balance in the body. Valine is used by bodybuilders, in conjunction with leucine and isoleucine, for muscle growth, tissue repair and as an energizer. There is little scientific evidence to support these claims, though studies have shown that these three substances might be able to help restore muscle mass in people with liver disease, injuries or who have undergone surgery, but no studies have shown them to be effective for healthy people. Because valine cannot be produced by the body, healthy people should ensure that they are obtaining at least the recommended amount in their diet. Valine can be metabolised to produce energy, which spares glucose. A deficiency may affect the myelin covering of the nerves. Recent studies indicate that valine, as well as leucine and isoleucine, may be effective in treating or reversing hepatic encephalopathy or alcohol related brain damage. It may also be useful in degenerative neurological conditions. Main food sources of valine are soy flour, raw brown rice, cottage cheese, fish, beef, lamb, chicken, almonds, brazil nuts cashews, peanuts, sesame seed, lentils, chickpeas and mushrooms. (22 May 1997) |
| valine-pyruvate transaminase | <enzyme> E coli enzyme catalyzing the terminal step of valine biosynthesis; consider also EC 2.6.1.42, branched-chain-amino-acid transaminase; alanine-alpha-oxoisovalerate aminotransferase and alanine-alpha-ketoisovalerate aminotransferase were ens to alanine aminotransferase 1981-93 Registry number: EC 2.6.1.66 Synonym: alanine-valine transaminase, transaminase c, alanine alpha-ketoisovalerate aminotransferase, alanine-alpha-oxoisovalerate aminotransferase, alanine-alpha-ketoisovalerate aminotransferase (26 Jun 1999) |
| valine-trna ligase | <enzyme> An enzyme that activates valine with its specific transfer RNA. Chemical name: L-Valine:tRNA(Val) ligase (AMP-forming) Registry number: EC 6.1.1.9 (12 Dec 1998) |
| endothelin-valine-generating endopeptidase | <enzyme> Cleaves big endothelin between val22 and asn23 Registry number: EC 3.4.21.- Synonym: big-et-ge (26 Jun 1999) |
| acidic amino acid | An Amino acid with a second acid moiety, e.g., glutamic acid, aspartic acid, cysteic acid. (05 Mar 2000) |
| activated amino acid | The product formed by the condensation of the acyl radical of an amino acid and adenosine 5'-monophosphate (originally in the form of adenosine 5'-triphosphate, with elimination of a pyrophosphoric group). Formed in the first step of protein biosynthesis. Synonym: activated amino acid. (05 Mar 2000) |
| alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid | <chemical> Alpha-amino-2,3-dihydro-5-methyl-3-oxo-4-isoxazolepropanoic acid. An ibotenic acid homolog and glutamate agonist. The compound is the defining agonist for the ampa subtype of glutamate receptors (receptors, ampa). It has been used as a radionuclide imaging agent but is more commonly used as an experimental tool in cell biological studies. Pharmacological action: excitatory amino acid agonists. Chemical name: 4-Isoxazolepropanoic acid, alpha-amino-2,3-dihydro-5-methyl-3-oxo- (12 Dec 1998) |
| alpha-amino acid | Typically, an amino acid of the general formula R-CHNH2-COOH (i.e., the NH2 in the a position); the l forms of these are the hydrolysis products of proteins. In rarer usages, this class of molecules also includes alpha-amino phosphoric acids and alpha-aminosulfonic acids. (05 Mar 2000) |
| alpha-amino acid esterase | <enzyme> Converts alpha-amino acid esters and water to alpha-amino acids and alcohol Registry number: EC 3.1.1.43 Synonym: alpha-amino acid ester hydrolase (26 Jun 1999) |
| alpha-amino-beta-ketoadipic acid | 2-Amino-3-oxo-1,6-hexanedioic acid;an intermediate of porphobilinogen synthesis formed by d-aminolevulinic acid synthase from succinyl-CoA and glycine; it rapidly decarboxylates to d-aminolevulinic acid. (05 Mar 2000) |
| amino acid | <biochemistry> A class of organic molecules that containing an amino group and can combine in linear arrays to form proteins in living organisms. There are twenty common amino acids: alanine, arginine, aspargine, aspartic acid, cysteine, glutamic acid, glutamine, glycine, histidine, isoleucine, leucine, lysine, methionine, phenylalanine, proline, serine, threonine, tryptophan, tyrosine, and valine. They are key components in all living things from which proteins are synthesised by formation of peptide bonds during ribosomal translation of messenger RNA. All the amino acids have the L configuration, except glycine which is not optically active. Other amino acids occurring in proteins, such as hydroxyproline in collagen, are formed by post translational enzymatic modification of amino acid residues in polypeptide chains. There are also several important amino acids, such as the neurotransmitter y aminobutyric acid, that have no relation to proteins. Amino acids can now be produced by biotechnology in bulk using fermentation and biotransformation. Acronym: AA (13 Nov 1997) |
| amino acid activating enzyme | <enzyme> Enzymes catalyzing the formation of a specific aminoacyl-tRNA from an amino acid and adenosine 5'-triphosphate with the concomitant formation of adenosine 5'-monophosphate and pyrophosphate. Synonym: amino acid activating enzyme, aminoacyl-tRNA ligases. (05 Mar 2000) |
| amino acid activation | The first step of protein synthesis, whereby an amino acid reacts with adenosine triphosphate in the presence of aminoacyl RNA synthetase to produce an amino acid adenylate, which provides the energy necessary for the attachment of the amino acid to a specific transfer RNA molecule. (12 Dec 1998) |