THE HISTOCHEMICAL DEMONSTRATION OF INTESTINAL β- d -FUCOSIDASE WITH 5-BROMO-4-CHLOROINDOLE-3-yl-β- d -FUCOPYRANOSIDE

Enzymatic hydrolysis of a halogen-substituted indolyl substrate for β-d-fucosidase shows a strong positive reaction in the interstitial mononuclear cells in the jejunum. This localization and the optimum pH are different from that of the analogous substrate for 3-d-galactosidase. The results of competitive inhibition of these substrates suggest that the reactions demonstrate distinct but similar tissue enzymes.