Anionic glutathione S-transferases of human erythrocytes, placenta, and lung: evidence for structural differences

Studies were undertaken to elucidate the structural interrelationships among glutathione S-transferase (GST) isozymes of human placenta, lung, and erythrocytes. Results of the high-performance liquid chromatography of the trypsin digests of the three isozymes indicate minor but significant differences in their elution profiles. Although a number of peptides generated by proteolysis were common for either 2 or 3 of the isozymes, significant differences were observed in elution profiles of other peptides. Qualitative as well as quantitative differences were also observed in the electrophoretic peptide maps of these isozymes. These studies suggest that there may be fine structural differences among the pi class GST isozymes of human tissues.