TY - BOOK AU - Volohonsky,G. AU - Tuby,C.N. AU - Porat,N. AU - Wellman-Rousseau,M. AU - Visvikis,A. AU - Leroy,P. AU - Rashi,S. AU - Rashi,S. AU - Stark,A.A. TI - A spectrophotometric assay of gamma-glutamylcysteine synthetase and glutathione synthetase in crude extracts from tissues and cultured mammalian cells N2 - An assay of gamma-glutamylcysteine synthetase (gamma-GCS)and glutathione synthetase (GS)in crude extracts of cultured cells and tissues is described. It represents a novel combination of known methods, and is based on the formation of glutathione (GSH)from cysteine, glutamate and glycine in the presence of rat kidney GS for the assay of gamma-GCS, or from gamma-glutamylcysteine and glycine for the assay of GS. GSH is then quantified by the Tietze recycling method. Assay mixtures contain the gamma-glutamyl transpeptidase (GGT)inhibitor acivicin in order to prevent the degradation of gamma-glutamylcysteine and of the accumulating GSH, and dithiothreitol in order to prevent the oxidation of cysteine and gamma-glutamylcysteine. gamma-GCS and GS levels determined by this method are comparable to those determined by others. The method is suitable for the rapid determination of gamma-GCS GS in GGT-containing tissues and for the studies of induction of gamma-GCS and GS in tissue cultures UR - https://drive.google.com/file/d/1SYrWQWxVj5Vw1rY8qhvDkA2z9yCyWmQo/view?usp=drivesdk ER -