| aspartate | <amino acid> A nonessential amino acid that plays a critical part of the enzyme in the liver that transfers nitrogen-containing amino groups, either in building new proteins and amino acids or in breaking down proteins and amino acids for energy and detoxifying the nitrogen in the form of urea. Depleted levels of aspartic acid may occur temporarily within certain tissues under stress, but, because the body is able to make its own aspartic acid to replace any depletion, deficiency states do not occur. Aspartic acid is abundant in plants, especially in sprouting seeds. In protein, it exists mainly in the form of its amide, asparagine. The popular sweetener Aspartame is a combination of aspartic acid and phenylalanine. Aspartic acid is considered nontoxic. (15 Nov 1997) |
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| aspartate 1-decarboxylase | <enzyme> A pyridoxal-phosphate protein that catalyses 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 gaba levels in normal nervous tissues. The brain enzyme also acts on l-cysteate, l-cysteine sulfinate, and l-aspartate. Chemical name: L-Glutamate-1-carboxy-lyase Registry number: EC 4.1.1.15 (12 Dec 1998) |
| aspartate 4-decarboxylase | Aspartate beta-decarboxylase;a carboxy-lyase converting l-aspartate to l-alanine (releasing CO2); it decarboxylates aminomalonate and (in bacteria) removes SO2 from cysteinesulfinate. See: desulfinase. (05 Mar 2000) |
| aspartate aminotransferase | <enzyme> An enzyme catalyzing the reversible transfer of an amine group from l-glutamic acid to oxaloacetic acid, forming alpha-ketoglutaric acid and l-aspartic acid; a diagnostic aid in viral hepatitis and in myocardial infarctions. Synonym: aspartate transaminase, glutamic-aspartic transaminase, glutamic-oxaloacetic transaminase, serum glutamic-oxaloacetic transaminase. (05 Mar 2000) |
| aspartate ammonia-lyase | <enzyme> An enzyme that catalyses the conversion of aspartic acid to ammonia and fumaric acid in plants and some microorganisms. Chemical name: L-Aspartate ammonia-lyase Registry number: EC 4.3.1.1 (12 Dec 1998) |
| aspartate carbamoyltransferase | <enzyme> An enzyme that catalyses the conversion of carbamoyl phosphate and l-aspartate to yield orthophosphate and n-carbamoyl-l-aspartate. Chemical name: Carbamoyl-phosphate:L-aspartate carbamoyltransferase Registry number: EC 2.1.3.2 (12 Dec 1998) |
| aspartate kinase | <enzyme> An enzyme that catalyses 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. Chemical name: ATP:L-aspartate 4-phosphotransferase Registry number: EC 2.7.2.4 (12 Dec 1998) |
| aspartate N-acetyltransferase | <enzyme> Nervous system enzyme that mediates synthesis of n-acetylaspartic acid; utilises acetyl-CoA Registry number: EC 2.3.1.17 (26 Jun 1999) |
| aspartate transaminase | <enzyme> An enzyme of the transferase class that catalyses the reaction of l-aspartate and 2-ketoglutarate to yield oxaloacetate and l-glutamate. The enzyme is a pyridoxal phosphate protein. In the liver the reaction transfers excess metabolic nitrogen into aspartate for disposal in the urea cycle. Chemical name: L-Aspartate:2-oxoglutarate aminotransaminase Registry number: EC 2.6.1.1 (12 Dec 1998) |
| aspartate-alpha-decarboxylase | <enzyme> Forms beta-alanine Registry number: EC 4.1.1.11 Synonym: aspartate 1-decarboxylase (26 Jun 1999) |
| aspartate-ammonia ligase | <enzyme> An enzyme that catalyses the formation of asparagine from ammonia and aspartic acid, in the presence of ATP. Chemical name: L-Aspartate:ammonia ligase (AMP-forming) Registry number: EC 6.3.1.1 (12 Dec 1998) |
| aspartate-saemialdehyde dehydrogenase | <enzyme> An enzyme that catalyses the conversion of l-aspartate 4-saemialdehyde, orthophosphate, and NADP+ to yield l-4-aspartyl phosphate and NADPH. Chemical name: L-Aspartate-4-saemialdehyde:NADP+ oxidoreductase (phosphorylating) Registry number: EC 1.2.1.11 (12 Dec 1998) |
| aspartate-trna ligase | <enzyme> An enzyme that activates aspartic acid with its specific transfer RNA. Chemical name: L-Aspartate:tRNA-(Asp) ligase (AMP-forming) Registry number: EC 6.1.1.12 (12 Dec 1998) |
| malate-aspartate shuttle | A mechanism for the transfer of NADH reducing equivalents from the cytosol into the mitochondria using two isozymes of malate dehydrogenase and aspartate transaminase. (05 Mar 2000) |
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| receptors, n-methyl-d-aspartate | A class of ionotropic glutamate receptors characterised 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. (12 Dec 1998) |
| potassium magnesium aspartate | <chemical> An intra-extracellular electrolyte exchange agent with a variety of effects. Beneficial in cardiac insufficiency, potentiates the effect of cardiac glycosides by reducing their toxicity, has hypocholesteraemic effects and potentiates the effects of calcium in disturbed calcium metabolism. Synonym: panangin; tromcardin. Chemical name: DL-Aspartic acid, monopotassium salt, mixt. With potassium hydrogen (T-4)-bis(DL-aspartato(2-)-N,O1)magnesate(2-) (12 Dec 1998) |
| protein-D-aspartate methyltransferase | <enzyme> For protein carboxymethylases consider also protein o-methyltransferase Registry number: EC 2.1.1.77 Synonym: d-aspartyl-l-isoaspartyl methyltransferase, protein d-aspartate-l-isoaspartate methyltransferase, protein l-isoaspartate o-methyltransferase, protein-beta-aspartate methyltransferase, protein-l-isoaspartate methyltransferase, protein l-isoaspartyl methyltransferase, isoaspartyl-aspartyl protein methyltransferase, protein-d-asp methyltransferase, l-isoaspartyl protein carboxymethyltransferase, pcm gene product, pcmt1 gene product (26 Jun 1999) |
| N-acyl-D-aspartate amidohydrolase | <enzyme> Specific for d-aspartate; amino acid sequence given in first source Registry number: EC 3.5.1.- Synonym: d-aaase, n-acyl-d-asp amidohydrolase (26 Jun 1999) |
| N methyl D aspartate receptor | <physiology> Glutamate receptor sub type (see excitatory amino acids). N methyl D aspartate receptor channels seem to be potentiated by intracellular arachidonic acid. Acronym: NMDA (26 Mar 1998) |
| IMP-aspartate ligase | <enzyme> A carbon-nitrogen ligase. During purine ribonucleotide biosynthesis, this enzyme catalyses the synthesis of adenylosuccinate from GTP, imp, and aspartate with the formation of orthophosphate and GDP. Chemical name: IMP:L-aspartate ligase (GDP-forming) Registry number: EC 6.3.4.4 (12 Dec 1998) |
| L-aspartate oxidase | <enzyme> E coli enzyme; forms unstable product, iminoaspartate; b protein of quinolinate synthetase Registry number: EC 1.4.3.16 Synonym: b-protein, quinolinate synthetase, l-aspartate - fumarate oxidoreductase (26 Jun 1999) |