L-kynurenine aminotransferase and L-[alpha]-aminoadipate aminotransferase. I. Evidence for identity

Abstract

SummaryThe following observations strongly suggest that L-kynurenine aminotransferase (KAT) and L-[alpha]-aminoadipate aminotransferase (AAT) activities are associated with the same protein: 1. a similar distribution in the supernatant and mitochondrial fractions of kidney and liver of male rats, 2. a similar distribution in these fractions of kidney and liver of female rats, 3. a similar sex difference in the supernatant and mitochondrial fractions of kidney with no sex difference in liver fractions, 4. a similar pattern of inhibition with a homologous series of dicarboxylic acids with adipate being most effective, 5. competitive inhibition of KAT with d,l-[alpha]-aminoadipate ([alpha]AA), 6. substrate inhibition of KAT with [alpha]-ketoadipate ([alpha]KA), and 7. AAT activity in a highly purified preparation of KAT. A scheme for the interaction of the two activities in lysine and tryptophan metabolism is presented.