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)

The enzyme 4-aminobutyrate aminotransferase (EC 2.6.1.19) isolated from Pseudomonas fluorescens was inhibited by the nucleotide ATP in an apparent competitive manner (Ki = 10.4 mM). This reversible effect was antagonized by the substrate GABA, whose apparent Km was increased from 0.6 mM to 2 mM in the presence of 20 mM ATP, suggesting that ATP interferes with GABA binding to the active site of the enzyme. The apparent Km with respect to the second substrate alpha-ketoglutarate was also increased, although to a lesser extent, whereas the cofactor pyridoxal 5'-phosphate was unable to influence the inhibition by ATP. The ATP structural analogues ADP, CTP and XTP were also able to inhibit the enzyme to a similar extent. These data indicate that GABA concentrations within the bacterial cell can be regulated by the action of ATP on 4-aminobutyrate aminotransferase. In addition, because the inhibition by ATP is similar to the inhibition of the enzyme from mammalian brain, the bacterial enzyme could provide a convenient source of the enzyme for studies of drug effects on brain GABA metabolism in vitro.
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PMID:Inhibition of 4-aminobutyrate aminotransferase from Pseudomonas fluorescens by ATP. 826 Sep 45