A highly glycosylated heterodimeric enzyme (γ-glutamyl transpeptidase, EC 220.127.116.11, 662 aa) attached to the outer surface of the plasma membrane that transfers a γ-l-glutamyl residue (usually from glutathione) to the amino group of an amino acid, e.g. in the conversion of leukotriene LTC4 to LTD4. The enzyme is widely distributed in tissues involved in absorption and secretion and there appear to be several γ-glutamyltransferase genes located on chromosome 22. Elevated plasma levels are used as a diagnostic marker of hepatic disorder and pancreatitis.
Subjects: Medicine and Health.