title: Classification of chitosanases by hydrolytic specificity toward N¹,N⁴-diacetylchitohexaose.
abstract: The hydrolytic specificities of chitosanases were determined using N¹,N⁴-diacetylchitohexaose [(GlcN)₂-GlcNAc-(GlcN)₂-GlcNAc]. The results for the hydrolytic specificities of chitosanases belonging to subclasses I, II, and III toward chitohexaose and N¹,N⁴-diacetylchitohexaose agreed with previous results obtained by analysis of the hydrolysis products of partially N-acetylated chitosan. N¹,N⁴-Diacetylchitohexaose is a useful substrate to determine the hydrolytic specificity of chitosanase. On the other hand, chitosanases from Amycolatopsis sp. CsO-2 and Pseudomonas sp. A-01 showed broad cleavage specificity. They cleaved both the GlcNAc-GlcN and the GlcN-GlcNAc bonds in addition to the GlcN-GlcN bond in the substrate. Thus, both enzymes were new chitosanases. The chitosanases were divided into four subclasses according to their specificity for hydrolysis of the β-glycosidic linkages in partially N-acetylated chitosan.
authors.affiliation: Department of Applied Biochemistry and Food Science, Faculty of Agriculture, Saga University, Saga, Japan.
authors.forename: Katsuaki
authors.initials: K
authors.lastname: Hirano
authors.forename: Masamichi
authors.initials: M
authors.lastname: Watanabe
authors.forename: Kiyohiko
authors.initials: K
authors.lastname: Seki
authors.forename: Akikazu
authors.initials: A
authors.lastname: Ando
authors.forename: Akihiro
authors.initials: A
authors.lastname: Saito
authors.forename: Masaru
authors.initials: M
authors.lastname: Mitsutomi
mesh_terms: D006026:Glycoside Hydrolases / Q000378:metabolism*; D006868:Hydrolysis; D009844:Oligosaccharides / Q000378:metabolism*; D011549:Pseudomonas / Q000201:enzymology; D013379:Substrate Specificity
chemical_list: D009844:Oligosaccharides; C050523:chitohexaose; D006026:Glycoside Hydrolases; C019868:chitosanase