PURIFICATION AND CHARACTERIZATION OF GLYOXALASE-II FROM HANSENULA-MRAKII

Glyoxalase II [S-(2-hydroxyacyl)glutathione hydrolase], one of the components of the glyoxalase system, catalyzes the hydrolysis of S-lactoylglutathione to glutathione and D-lactic acid. The enzyme was partially purified from the yeast Hansenula mrakii IFO 0895 by successive column chromatographies and polyacrylamide gel electrophoresis. The molecular weight of the enzyme was estimated to be 22,000 daltons by gel-filtration of Sephadex G-150 column chromatography and 24,000 daltons by SDS-polyacrylamide gel electrophoresis. The enzyme was specific to S-lactoylglutathione and S-acetylglutathione. The activity of the enzyme was strongly inhibited by Cu2+, p-chloromercuribenzoate and HgCl2. The enzyme activity was also inhibited by hemimercaptal, a non-enzymatic condensation product between glutathione and methylglyoxal.