Department of Chemistry, Northwestern University Evanston, Illinois 60201 USA
Abstract:
γ-Aminobutyric acid-α-ketoglutarate transaminase from pig brain is irreversibly inactivated by 4-amino-5-halopentanoic acids. Protection from inactivation by the natural substrates, the pH dependence of inactivation and the incorporation of 1.7 moles of radioactive inhibitor per mole of enzyme from (S)-U-14C]-4-amino-5-chloropentanoic acid suggest a covalent adduct at the active site of the enzyme. A mechanism-based inactivation is proposed.