Gamma glutamyl transferase: application of a new radiochemical assay to the analysis of its subcellular distribution in the rat liver.
gamma-Glutamyl transferase (gamma-GT) is a key catalyst in the metabolism of glutathione. Its activity in the rat liver is usually very low but it increases significantly during the process of chemical hepatocarcinogenesis. A new radiochemical assay is reported which measures the amount of 3H-aniline liberated from gamma-glutamyl-3H-anilide. This assay is highly specific and no biological substances interferes. By applying this new assay to the analysis of the subcellular distribution of the rat liver gamma-GT, it is shown that it distributes between two pools, one which corresponds to a membrane-bound enzyme, the other to a soluble enzyme. The subcellular distribution of gamma-GT is discussed by comparison with the patterns of distribution of classical marker enzymes.
D000818:Animals; D008099:Liver / Q000201:enzymology*; D008722:Methods; D008862:Microsomes, Liver / Q000201:enzymology; D051381:Rats; D012995:Solubility; D013347:Subcellular Fractions / Q000201:enzymology; D005723:gamma-Glutamyltransferase / Q000032:analysis / Q000378:metabolism*
D005723:gamma-Glutamyltransferase