ACTION PATTERN OF AEROMONAS-HYDROPHILA CHITINASE ON PARTIALLY N-ACETYLATED CHITOSAN

Oligosaccharides from the digestion of 34% N-acetylated chitosan by Aeromonas hydrophila chitinase were separated by CM-Sephadex C-25 column chromatography. Sugar compositions and the sequences of main oligosaccharides were identified through their N-acetylation, their cleavage with exo-glycosidases, and their degradation with nitrous acid. Hetero-chitooligosaccharides such as GlcN · GlcNAc, GlcN · GlcNAc · GlcNAc, GlcNAc · GlcN · GlcNAc, and GlcNAc · GlcN · GlcNAc · GlcNAc, together with GlcNAc and (GlcNAc)2, were detected. The structure of GlcN · GlcNAc was confirmed by the analysis with proton and carbon NMR spectroscopy. These studies indicate that Aeromonas hydrophila chitinase is more specific toward the N-acetyl-β-d-glucosaminidic bonds in partially N-acetylated chitosan. © 1990 by the Japan Society for Bioscience, Biotechnology, and Agrochemistry. All rights reserved.