Purification and Characterization of α-Glucuronidase from Snail Acetone Powder

Abstract

We have purified the p-nitrophenyl α-D-glucuronide-hydrolyzing enzyme (PNP-GAase) from snail (Helix pomatia) acetone powder by chromatographies on DEAE-cellulose, CM-Toyopearl, and Toyopearl HW-55F. The molecular weight of the enzyme was 180, 000 by gel filtration chromatography with Superose 6, and 97, 000 by SDS-polyacrylamide gel electrophoresis, and the pI was 6.8 by isoelectric focusing. The enzyme showed the maximum activity at pH 3.0 and 50°C, and was stable at pH between 3.0-7.0 and up to 50°C. The enzyme activity was greatly inhibited by Hg²⁺, p-chloromercuribenzoic acid, sodium dodecylsulfate, and N-bromosuccinimide. The enzyme released D-glucuronic acid not only from PNP-GA but also from 2-, 3-, and 4-O-α-D-glucuronosyl-D-xyloses, O-α-D-glucuronosyl α-D-glucuronide, and benzyl 4-O-α-D-glucuronosyl-β-D-glucoside. The results suggest that the α-glucuronidase from snail acetone powder had a broad substrate specificity comparing with α-glucuronidases from Aspergillus niger and basidiomycetes.