The isolation and characterization of mouse liver glyoxalase I.

The purification of glyoxalase I (S-lactoyl-glutathione methylglyoxal-lyase (isomerizing) EC 4.4.1.5) from DBA/1J mouse liver employing ion exchange and affinity chromatography is described. The enzyme was purified 1140-fold and it exhibits a specific activity of 2200 units/mg of protein. The activity was determined to be homogeneous by sedimentation velocity and sedimentation equilibrium ultracentrifugation and by polyacrylamide electrophoresis. The molecular weight is approimately 43 000 and the sedimentation coefficient is 3.4 S. Kinetic data are consistent with a one-substrate (hemimercaptal) reaction mechanism but do not rule out alternate branches at low substrate and free glutathione concentrations.