Enzymatic hydrolysis of 2,4-diketo acids.

In the course of studies on the desamidation of glutamine in rat liver extracts marked acceleration of this reaction was noted in the presence of 2,4-diketovaleric acid (acetopyruvic acid) .l Recent work indicates that pyruvic acid and certain other ar-keto acids increase the desamidation of glutamine in aqueous extracts of normal and neoplastic rat liver (l-3). Investigation of the mechanism of the acceleration of glutamine desamidation by 2,4-diketovaleric acid revealed that this effect was actually due to pyruvic acid formed by hydrolysis of the diketo acid and that 2,4-diketovaleric acid itself was apparently inactive in the glutamine system (4). This finding led to experiments on other 2,4-diketo acids. The present studies demonstrate the existence of a hitherto unrecognized enzymatic reaction occurring in extracts of liver and kidney, whereby a wide variety of 2,4-diketo acids (acylpyruvic acids) are hydrolyzed to yield pyruvic acid and the corresponding fatty acid.