Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P80404 (GABA transaminase)
 786 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Metabolism of the glutamate group of amino acids--glutamic acid, gamma-amino-butyric acid, glutamine, aspartic acid and alanine--was studied in the brain of rat as a function of age. The levels of glutamic acid, glutamine and aspartic acid decreased while those of gamma-aminobutyric acid, and alanine increased with age. The results on the activity of the twelve enzymes involved in the metabolism showed that five of them (glutamate dehydrogenase, glutamine synthase, gamma-aminobutyric acid transaminase, succinic semialdehyde dehydrogenase and NAD+-isocitrate dehydrogenase) decreased, while four of them (glutaminase, glutamotransferase, glutamic acid decarboxylase, and alpha-ketoglutarate dehydrogenase) increased. The other three enzymes (aspartate aminotransferase, alanine aminotransferase and NADP+-isocitrate dehydrogenase) did not show any significant change in activity. An age-related increase was seen in alpha-ketoglutarate and ammonia, the intermediates involved in the metabolism of these amino acids. The changes in the level of these amino acids are discussed in relation to the altered energy metabolism during aging.
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PMID:Metabolism of the glutamate group of amino acids in rat brain as a function of age. 614 62

Homotaurine (3-aminopropanesulfonate), a natural product and an analogue of GABA (4-aminobutyrate), was found to be a sole source of nitrogen for Cupriavidus necator (Ralstonia eutropha) H16, whose genome sequence is known. Homotaurine nitrogen was assimilated into cell material, and the quantitative fate of the organosulfonate was sulfopropanoate, which was recovered in the growth medium. The first scalar reaction was shown to be inducible homotaurine:2-oxoglutarate aminotransferase, which released 3-sulfopropanal from homotaurine. This aminotransferase was purified to homogeneity and characterized. Peptide mass fingerprinting yielded locus tag H16_B0981, which was annotated gabT, for GABA transaminase (EC 2.6.1.19). Inducible, NAD(P)(+)-coupled 3-sulfopropanal dehydrogenase, which yielded 3-sulfopropanoate from 3-sulfopropanal, was also purified and characterized. Peptide mass fingerprinting yielded locus tag H16_B0982, which was annotated gabD1, for succinate-semialdehyde dehydrogenase (EC 1.2.1.16). GabT and GabD1 were each induced during growth with GABA, and cotranscription of gabTD was observed. In other organisms, regulator GabC or GabR is encoded contiguous with gabTD: candidate GabR' was found in strain H16 and in many other organisms. An orthologue of the GABA permease (GabP), established in Escherichia coli, is present at H16_B1890, and it was transcribed constitutively. We presume that GabR'PTD are responsible for the inducible metabolism of homotaurine to intracellular 3-sulfopropanoate. The nature of the exporter of this highly charged compound was unclear until we realized from the sodium dodecyl sulfate-polyacrylamide gel electrophoresis data that sulfoacetaldehyde acetyltransferase (EC 2.3.3.15; H16_B1872) was strongly induced during growth with homotaurine and inferred that the sulfite exporter encoded at the end of the gene cluster (H16_B1874) has a broad substrate range that includes 3-sulfopropanoate.
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PMID:Homotaurine metabolized to 3-sulfopropanoate in Cupriavidus necator H16: enzymes and genes in a patchwork pathway. 1964 35