Purification and characterization of a new form of glutathione S-transferase from human erythrocytes.

Presence of a new form of glutathione S-transferase has been demonstrated in human erythrocytes. Using two different affinity ligands this enzyme has been separated from the previously characterized glutathione S-transferases rho. The new enzyme is highly basic with a pI of greater than 10. The new enzyme which represents less than 5 percent of glutathione-S-transferase activity towards 1-chloro-2,4-dinitrobenzene as substrate and about 10 percent of total glutathione S-transferase protein of erythrocytes has different amino acid composition, substrate specificities, and immunological characteristics from those of the major erythrocyte glutathione S-transferase rho. Immunological properties of the new enzyme indicate that this form may be different from other glutathione S-transferases of human tissues.