Separation and Specificity of the Yeast Glutamate-α-Ketoadipate Transaminase

Yeast glutamate-α-ketoadipate transaminase activity exhibited differences in differential heat inactivation, pH dependence, response to pyridoxal phosphate, ammonium sulfate fractionation, diethylaminoethyl cellulose chromatography, and mutational independence from other known transaminases. Both yeast glutamate-α-ketoadipate transaminase and glutamate-pyruvate transaminase were found to be present in two varieties separable on DEAE-cellulose and Sephadex G-200 chromatography. Only one form of glutamate-oxalacetate transaminase was found. Yeast mitochondria exhibited glutamate-oxalacetate transaminase activity and only one of the varieties of each of the other transaminases. Biosynthesis of α-aminoadipate may be a mitochondrial function in Saccharomyces.