COENZYMES FOR GLYOXALASE

Abstract

In 1932 Lohmann (1) first demonstrated t,he role of glutathionc as the coenzyme for glyoxalase in the conversion of mebhylglyoxal to lactic acid.Lohmann, moreover, demonstrated that reduced glutathione was extremely specific in its role as coenzyme.Oxidized glutathione, cysteine, thioglycolic acid, hydrogen sulfide, hydrocyanic acid, hydroxyquinoline, citrate, and pyrophosphate were all found to be inactive.To the list of inactive substances Woodward (2) added thioneine and ascorbic acid.On the basis of iodomctric titrations Kiihnau (3) postulated the t'heory that glutathione and methylglyoxal form a combination.Jowett and Quastel (4) presented further evidence indicating that glutathione and methylglyoxal combine reversibly.Their evidence led them to suggest that the addition compound served as the substrate for glyoxalase according to the following equation.