Microfluorometry of Brain Trypsin-Like Activity and Trypsin Inhibition with N-Carbobenzoxydiglycyl- L-arginine-2-naphthylamide (GGANA)

Abstract

A microfluorometric method is described for the assay of trypsin, of trypsinlike activity of brain tissue and of trypsin inhibition by brain tissue. Characteristics of these assays with the fluorogenic substrate Ncarbobenzoxydiglycyl- L-arginine-2-naphthylamine (GGANA) are described. As little as 0.5 mg (0.25 mg/ml) of brain tissue or 0.5 pg of bovine trypsin are required. The ‘neutral proteinase’ of rat brain studied had a pH optimum at 7.3—7.4 and was inhibited by calcium. Trypsin inhibition by brain homogenates had peaks at pH 7.8 and 8.4.