Studies on glutathione S-alkyltransferase of the rat.

1. A rat-liver enzyme catalysing the S-alkylation of glutathione by iodomethane and various other alkyl compounds has been identified and partially purified; its stability, specificity and response to inhibitors and activators and to changes in reaction pH have been studied. 2. The enzyme is distinct from glutathione S-aryltransferase, but both enzymes respond similarly to various inhibitors. 3. A similar enzyme has been found in the kidney and adrenal of rat and in the liver and kidney of numerous species. 4. The identity and the physiological role of the enzyme are discussed.