Purification and characterization of the two forms of glutathione S-transferase present in human lens

Human lens has two forms of glutathione S-transferase having pI values of greater than 10 and 4.4. Both of these enzymes may have been purified to an apparent homogeneity from normal human lenses using glutathione affinity chromatography and isoelectric focusing. These two isoenzymes are significantly different from each other in their kinetic, structural, and immunological properties. The cationic form (pI greater than 10) is a dimer of Mr 24 500 subunits whereas the anionic form (pI 4.4) is a dimer of Mr 22 500 subunits. Neither of the two forms express selenium-independent glutathione peroxidase II activity.