Studies on gamma-glutamyl transpeptidase will include the localization of the functional sites on the two non-identical subunits. Partial reactions of the separated subunits will be ascertained. The enzyme is membrane-bound and will be localized by ferritin-conjugated antibodies against the whole enzyme and its subunits. The possible role of the enzyme in transport and transmembrane catalysis will be determined, and characterization of the functional unit containing this enzyme will be conducted after its specific isolation in a nearly "native environment".