HISTOCHEMICAL DEMONSTRATION OF A GAMMA-GLUTAMYL TRANSPEPTIDASE-LIKE ACTIVITY

Abstract

A histochemical method for the demonstration of a γ-glutamyl transpeptidase-like enzymic activity using N(γ-glutamyl)β-naphthylamide as substrate in a simultaneous diazonium coupling reaction has revealed many tissue localizations distinct from those noted with other peptidase substrates. The biochemical and histochemical evidence presented suggests that at the pH of the histochemical reaction both a transpeptidase and hydrolytic reaction mediated by the same enzyme occurs and, as indicated by histochemical inhibitor studies, the characteristics of the activity appear to be identical with those of γ-glutamyl transpeptidase as defined biochemically.