Purification and characterization of glutathione-S-transferase from liver cytosol of phenobarbital-treated rabbits.

Glutathione-S-transferase (GST) from the liver cytosol of phenobarbital (PB)-treated rabbits was purified by DEAE-cellulose, CM-cellulose and hydroxylapatite column chromatography. Four species of GST were obtained by eluting the CM-cellulose column with a linear KCl gradient, and the major protein investigated. The purified enzyme from PB-treated and untreated rabbit had specific activities of 125.16 units/mg and 72.8 units/mg of protein, respectively, and the apparent Km was 0.6 X 10(-3) M for GSH and 1.6 X 10(-3) M for 1-chloro-2,4-dinitrobenzene. The optimum pH value was 8.7 and the enzyme was able to conjugate with 1-chloro-2,4-dinitrobenzene, 1,2-dichloro-4-nitrobenzene, 1,2-epoxy-3-(p-nitrophenoxy)propane and p-nitrobenzyl chloride.