Alpha-Glutamyl-beta-naphthylamide hydrolase of rabbit small intestine. Localization in the brush border and separation from other brush border peptidases

Abstract

About 70% of the total mucosal enzymatic activity hydrolyzing beta-L-glutamyl-beta-naphthylamide in the rabbit small intestine is present in the brush border; the specific activity in this subcellular fraction is 7 times higher than that of the homogenate. Similar results are obtained for L-leucyl beta-naphthylamide hydrolase. The enzyme activity is efficiently solubilized by papain digestion and is clearly separated from L-leucyl-beta-naphthylamide hydrolase by chromatography on concanavalin A-Sepharose. It probably represents a digestive peptidase, different from the other known peptide hydrolases of the digestive surface of the small intestine.