Purification of rat liver microsomal glutathione transferase

The rat liver microsomal glutathione transferase was activated by N-ethylmaleimide, solubilized by Triton X-100 and purified by chromatography on hydroxyapatite and CM Sephadex C-50. A 28-fold purification resulted in a 38% yield. The purified protein moved as a band with an apparent molecular weight of 14,000 on sodium dodecyl sulphate polyacrylamide gel electrophoresis and appeared to be nearly homogeneous. The N-terminal amino acid of the purified enzyme was alanine, identified by the dansyl method. Optimum pH and temperature were 6.8 and 30 degrees C, respectively.