Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:2.6.1.19 (GABA transaminase)
 808 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Among pyrimidine derivatives, we found that 5-fluorouracil potently inhibited purified rat liver D-3-aminoisobutyrate-pyruvate aminotransferase, whereas 5-fluorouridine did so to a much lesser extent. 5-Fluorouracil acted as a competitive inhibitor against beta-alanine with a Ki of 56 microM, and was uncompetitive against pyruvic acid, with a Ki of 73 microM. alpha-Fluoro-beta-alanine, a metabolite of 5-fluorouracil, was also a competitive inhibitor with respect to beta-alanine with a Ki of 8.0 mM. 5-Fluorouracil acted also as a competitive inhibitor of 4-aminobutyrate aminotransferase with respect to beta-alanine with a Ki value of 1.9 mM, and was uncompetitive against 2-oxoglutaric acid, with a Ki of 1.8 mM.
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PMID:Inhibition of D-3-aminoisobutyrate-pyruvate aminotransferase by 5-fluorouracil and alpha-fluoro-beta-alanine. 163 95

The effect of dietary protein on pyrimidine-metabolizing enzymes was studied in the rat. The activities of dihydropyrimidine dehydrogenase and beta-ureidopropionase in the livers of rats fed a protein-free diet were significantly decreased, while the activity of dihydropyrimidinase was unaffected. Protein deficiency (5%) also decreased the activity of beta-ureidopropionase. On the other hand, a high-protein diet (60%) increased the level of beta-ureidopropionase. The activities of beta-alanine-oxoglutarate aminotransferase (aminobutyrate aminotransferase) and D-3-aminoisobutyrate-pyruvate aminotransferase ((R)-3-amino-2-methylpropionate-pyruvate aminotransferase), which are present in mitochondria, depended on the amount of protein in the diet. Ammonium ions supplemented in the diet and given by injection did not affect the activities of rat liver pyrimidine-metabolizing enzymes (dihydropyrimidine dehydrogenase, dihydropyrimidinase, beta-ureidopropionase, beta-alanine-oxoglutarate aminotransferase and D-3-aminoisobutyrate-pyruvate aminotransferase). Dietary uridine resulted in the accumulation of uracil in the liver, but did not affect the activities of pyrimidine-metabolizing enzymes.
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PMID:Effect of dietary protein on pyrimidine-metabolizing enzymes in rats. 180 76

The conversion of (R)- to (S)-beta-aminoisobutyrate was observed in the presence of D-3-aminoisobutyrate-pyruvate aminotransferase, aminobutyrate aminotransferase, pyruvate and L-glutamate. The reverse reaction was also found in the presence of 2-oxoglutarate and L-alanine. Neither D-3-aminoisobutyrate-pyruvate aminotransferase nor aminobutyrate aminotransferase revealed a racemase activity of the enantiomorphs.
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PMID:Evaluation of interconversion between (R)- and (S)-enantiomers of beta-aminoisobutyrate. 197 65

Gabaculine, 5-amino-1,3-cyclohexadienylcarboxylate, is an analogue of GABA and a potent irreversible inhibitor of GABA aminotransferase. However, D-3-aminoisobutyrate-pyruvate aminotransferase for which GABA was neither a substrate nor an inhibitor was also inactivated by gabaculine. The Ki for D-3-aminoisobutyrate-pyruvate aminotransferase was 8.3 x 10(-6) M, and the Kcat for its turnover was 0.31 min-1 at 25 degrees C. beta-Alanine protected the enzyme from inactivation by gabaculine, but GABA did so to much a lesser extent.
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PMID:Irreversible inhibition of D-3-aminoisobutyrate-pyruvate aminotransferase by gabaculine. 212 4

The effect of 6-azauracil on beta-alanine metabolism was investigated in vivo in the rat. Both of the enzymes beta-alanine-oxoglutarate aminotransferase (aminobutyrate aminotransferase) and D-3-aminoisobutyrate-pyruvate aminotransferase [R)-3-amino-2-methylpropionate-pyruvate aminotransferase), which are beta-alanine catabolizing enzymes from rat liver and kidney, were inactivated by 6-azauracil injection, while dihydrouracil dehydrogenase, dihydropyrimidinase, and beta-ureidopropionase, which are pyrimidine metabolizing enzymes, were not affected. The content of beta-alanine was increased, but the level of uridine and uracil in rat liver was not affected, by 6-azauracil. When a crude enzyme preparation was passed through a Sephacryl S-200 column, both enzymes could be separated from each other. beta-Alanine-oxoglutarate aminotransferase and beta-alanine-pyruvate aminotransferase activities in rat liver decreased to 27.4% and 63.9%, respectively, upon 6-azauracil injection, and those in kidney were 11.7% and 38.3%, respectively. From these findings, it is suggested that the accumulation of beta-alanine in 6-azauracil-treated rat liver might be caused by the inhibition of beta-alanine catabolizing enzymes, but not by an increase in the uridine pool nor by the activation of pyrimidine metabolism.
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PMID:Inhibitory effect of 6-azauracil on beta-alanine metabolism in rat. 263 79

D-3-Aminoisobutyrate-pyruvate aminotransferase (EC 2.6.1.40) and alanine-glyoxylate aminotransferase 2 (EC 2.6.1.44) were co-purified from rat liver as a single protein. The ratio of the two activities remained constant after Sephacryl S-200 chromatography and chromatofocussing. The Km value for beta-alanine as a substrate with 1 mM glyloxylate as amino group acceptor was 1.4 mM. The activity was inhibited by (S)-alanine with Ki = 2.2 mM. The Km for (S)-alanine as substrate with 1 mM glyoxylate as amino group was 6 mM. This activity was inhibited competitively by beta-alanine with Ki = 0.7 mM. (R)-3-aminoisobutyric acid, 5-aminolevulinic acid, NG,NG'-dimethyl-(S)-arginine, and (S)-2-aminobutyric acid were active competitively with respect to beta-alanine with Km of 0.12 mM, 2.1 mM, 6.4 mM and 11.3 mM, respectively. Antiserum to rat liver D-3-aminoisobutyrate-pyruvate aminotransferase inhibited alanine-glyoxylate aminotransferase activity in rat liver in the same way as that of D-3-aminoisobutyrate-pyruvate aminotransferase. Alanine-glyoxylate aminotransferase activity and D-3-aminoisobutyrate-pyruvate aminotransferase activities were inactivated competitively with respect to beta-alanine by 5-fluorouracil and 6-azauracil, which are chemotherapeutic reagents used to cancer. These experiments indicate that D-3-aminoisobutyrate-pyruvate aminotransferase is identical with alanine-glyoxylate aminotransferase 2, aminolevulinate aminotransferase, 2-aminobutyrate aminotransferase and dimetylarginine-pyruvate aminotransferase.
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PMID:Identity of D-3-aminoisobutyrate-pyruvate aminotransferase with alanine-glyoxylate aminotransferase 2. 842 75