Competitive inhibition of mouse brain gamma-aminobutyrate aminotransferase by ATP.
The nucleotide ATP was shown to be a reversible inhibitor of partially purified gamma-aminobutyrate aminotransferase isolated from mouse brain. This inhibition was of the competitive type with respect to the substrate, gamma-aminobutyric acid (Ki = 3.7 +/- 0.6 mM), but was noncompetitive with respect to both the second substrate alpha-ketoglutarate and the cofactor pyridoxal 5'-phosphate. Two analogues of ATP, ADP and GTP, also gave rise to an inhibition gamma-aminobutyrate aminotransferase that was similar to that produced by ATP. These results are consistent with the view that mouse brain gamma-aminobutyric acid aminotransferase could be under regulatory control by ATP and certain other nucleotides within the mitochondria.
Tunnicliff
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Indiana University School of Medicine, Evansville 47712.
Youngs
T L
TL
D000612:4-Aminobutyrate Transaminase / Q000037:antagonists & inhibitors* / Q000378:metabolism; D000244:Adenosine Diphosphate / Q000494:pharmacology; D000255:Adenosine Triphosphate / Q000494:pharmacology*; D000818:Animals; D001667:Binding, Competitive; D001921:Brain / Q000201:enzymology*; D006160:Guanosine Triphosphate / Q000494:pharmacology; D007656:Ketoglutaric Acids / Q000378:metabolism; D007700:Kinetics; D008297:Male; D051379:Mice; D008813:Mice, Inbred ICR; D011732:Pyridoxal Phosphate / Q000378:metabolism; D005680:gamma-Aminobutyric Acid / Q000378:metabolism
D007656:Ketoglutaric Acids; D005680:gamma-Aminobutyric Acid; D011732:Pyridoxal Phosphate; D000244:Adenosine Diphosphate; D006160:Guanosine Triphosphate; D000255:Adenosine Triphosphate; D000612:4-Aminobutyrate Transaminase