Substrate specificity of α-glucuronidase isolated from snail acetone powder

Abstract

The substrate specificity of a p-nitrophenyl α-D-glucopyranosyl- uronic acid-hydrolyzing enzyme (PNP-GAase) isolated from snail acetone powder has been investigated with various substrates, such as p-nitrophenyl α-D-glucopyranosyluronic acid (PNP-GA), 2–O-α-i)-glucopyranosyluronic acid-D-xvlose (GA-2X), 2–O-(4–O-methyl-α-u-glucopyranosyluronic acid)-D-xylose (MeGA-2X), and O-α-1) glucopyranosyluronic acid-α-D-glucopyranosiduronic acid (GA-GA). The Km (mM) and Vmax (μmol of glucuronic acid formed/mg of enzyme protein/min) toward these substrates were as follows; 0,13 and 3,21 for PNP-GA, 0,33 and 0,089 for GA-2X, 17,6 and 0,094 for MeGA-2X, and 0,36 and 0,015 for GA-GA, respectively. The results indicate that the PNP-GAase specifically hydrolyzed PNP-GA, however, the enzyme had broad substrate specificity. © 1996, Taylor & Francis Group, LLC. All rights reserved.