Catalytic inhibition of γ-aminobutyric acid-α-ketoglutarate transaminase of bacterial origin by 4-aminohex-5-ynoic acid, a substrate analog

γ-Aminobutyric acid-α-ketoglutarate transaminase from Pseudomonas fluorescens is irreversibly inhibited by 4-aminohex-5-yhoic acid, a new structural analog of GABA. The fact that this inhibition requires the pyridoxal form of the holoenzyme, and the formation of a Michaelis complex is in support of a catalytic mechanism. The compound is also active in vitro and in vivo on the same enzyme from mammalian brain.