Cationic glutathione S-transferase of human erythrocytes has unique kinetic characteristics among human glutathione S-transferases.

The cationic glutathione S-transferase (GST sigma) of human erythrocytes is activated when incubated with 1 mM N-ethylmaleimide or other sulfhydryl blocking agents. Other GST isoenzymes of human tissues were inhibited by these reagents under similar conditions. At higher concentrations of NEM, GST sigma was also inhibited. Dithiothreitol, 2-mercaptoethanol, and sodium borohydride also caused several fold activation of GST sigma but noe of the other human GST isoenzymes were activated by these reagents.