GLUTATHIONE S-TRANSFERASE FROM HEVEA-BRASILIENSIS

Glutathione (GSH) S-transferase can be detected in a variety of tissues of H. brasiliensis. Lyophilized powders prepared from 20,000 g supernatants of latex adjusted to pH 5.0 contain substantial amounts of GSH S-transferase activity which is stable at -20.degree. for up to 6 mo. The enzyme has a broad pH optimum between 8.5 and 9.5. The Km values for GSH and 1-chloro-2,4-dinitrobenzene are in the range of 33-45 and 150-200 .mu.M, respectively. The enzyme has a MW in the range of 47,000-50,000 and an isoelectric point of 4.3. Although it appears homogeneous on analytical polyacrylamide disc gel electrophoresis (PAGE) and isoelectric focusing, it resolves into 5 forms on DEAE-Sephadex chromatography.