Irreversible inhibition of D-3-aminoisobutyrate-pyruvate aminotransferase by gabaculine

FEBS Lett. 1990 Dec 10;276(1-2):115-8. doi: 10.1016/0014-5793(90)80521-j.

Abstract

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.

MeSH terms

  • 4-Aminobutyrate Transaminase / antagonists & inhibitors
  • Alanine Transaminase / antagonists & inhibitors
  • Alanine Transaminase / isolation & purification
  • Animals
  • Cyclohexanecarboxylic Acids / pharmacology*
  • Isoenzymes / antagonists & inhibitors
  • Kinetics
  • Liver / enzymology
  • Pseudomonas fluorescens / enzymology
  • Rats
  • Transaminases / antagonists & inhibitors*
  • beta-Alanine / pharmacology
  • gamma-Aminobutyric Acid / pharmacology

Substances

  • Cyclohexanecarboxylic Acids
  • Isoenzymes
  • beta-Alanine
  • gabaculine
  • gamma-Aminobutyric Acid
  • Transaminases
  • 4-Aminobutyrate Transaminase
  • Alanine Transaminase
  • D-3-aminoisobutyrate-pyruvate aminotransferase