Differentiation between alanine-glutamate and alanine-glycine transaminase activities of penicillium martensii

ABSTRACT

Dialyzed cell-free extracts of Penicillium martensii contained, at the constitutive level, two different alanine transaminase catalyzing the formation of pyruvate and glutamate from alanine and alpha- oxoglutarate. The second was alanine-glycine from alanine and glyoxylate. The reversibility of the two reactions was demonstrated. Optimum activity of both enzymes occurred at pH 8.0 and 40C, but their temperature activity profiles and heat inactivation kinetics were different. The activity of the two enzymes was stimulated by addition of pyridoxal phosphate, whereas hydroxylamine inhibited it. The inhibition by hydroxylamine was overcome by pyridoxal phosphate