Comparative Enzymology of Glyoxalase I

The role of the metal ion in rat erythrocyte glyoxalase I was evaluated. The apoenzyme was formed by dialysis against an EDTA-imidazole buffer. Fluorescence studies of the Mg++- and Mn++-dansylated glyoxalase I\u27s suggest that the metal ion is near the active site of the enzyme and participates in the catalytic reaction. Stereochemical studies of the conversion of methylglyoxal to S-lactoylglutathione with Mg++, Mn++, Co++ and Ni++-glyoxalase I\u27s show that the 0-lactate of S-lactoylglutathione (97±1.5%) is formed. This result suggests that the reaction mechanism is the same with a change in metal ion