Purification and Some Properties of β-N-Acetylglucosaminidase from Aeromonas sp. 10S-24

Abstract

β-N-Acetylglucosaminidase (EC 3.2.1.30) was purified from a cell-free extract of Aeromonas sp. 10S-24 by precipitation with ammonium sulfate and column chromatographies with DEAE-Toyopearl, Sephacryl S-200 HR, chromatofocusing, and Q-Sepharose. The purified enzyme was homogeneous on polyacrylamide gel electrophoresis. The molecular weight was about 103, 000 by SDS-PAGE, and 100, 000 by gel filtration. The pI was 5.05 by chromatofocusing. The optimum pH was 7.0 and the stable pH was around 7.0. The enzyme was potently inhibited by various metal ions and SH reagents. The K_m was 0.27 mM for p-nitrophenyl-β-D-N-acetylglucosaminide. The enzyme hydrolyzed N-acetylchitooligosaccharides, di-N-acetylchitobiose through hexa-N-acetylchitohexaose.