Hydrolytic Model of Chitosanases Produced with Aspergillus CJ22-326

Hydrolytic model of two chitosanases of chitosan, ChiB and ChiA, separated and purified from a culture filtrate of Aspergillus CJ22-326, was investigated. The experimental results on the viscosity changes of reaction solution and analysis of enzymatic hydrolysis products by TLC and HPLC showed that ChiB was an endo-type cleavage enzyme. ChiB decreased the viscosity of reaction solution significantly, hydrolyzed 1341,4) glucosidic bond of chitosan at random. Using chitooligosaccharides as substrates, ChiB acted on GleN-GleN and did not act on G1cNAc - G1cNAc glucosidic bond. Chitooligosaccharides with the degree of polymerization below 5 could not be hydrolyzed by ChiB. Hydrolysis products of chitopentose were chitobiose and chitotriose. The latter was the main product of chitohexaose hydrolysis. ChiA was an exo-type amino-glucosidase which mainly cleaved glucosamine residue from non-reducing end of chitosan or chitooligosaccharides. ChiA acted only on GlcN - GlcN and GlcN - GleNAc glucosidic bonds.