Kadokura K, Rokutani A, Yamamoto M, Ikegami T, Sugita H, Itoi S, Hakamata W, Oku T, Nishio T
Department of Biological Chemistry, College of Bioresource Sciences, Nihon University, 1866 Kameino, Fujisawa, Kanagawa, 252-8510, Japan.
Appl Microbiol Biotechnol. 2007 May;75(2):357-65. doi: 10.1007/s00253-006-0831-6. Epub 2007 Mar 3.
A chitin-degrading bacterial strain, KN1699, isolated from Yatsu dry beach (Narashino, Chiba Prefecture, Japan), was identified as Vibrio parahaemolyticus. Treatment of powdered chitin with crude enzyme solution prepared from the supernatant of KN1699 cultures yielded a disaccharide, beta-D-N-acetylglucosaminyl-(1,4)-D-glucosamine (GlcNAc-GlcN), as the primary chitin degradation product. The extracellular enzymes involved in the production of this heterodisaccharide, chitinase (Pa-Chi; molecular mass, 92 kDa) and chitin oligosaccharide deacetylase (Pa-COD; molecular mass, 46 kDa), were isolated from the crude enzyme solution, and their hydrolysis specificities were elucidated. These studies confirmed that (1) Pa-Chi hydrolyzes chitin to produce (GlcNAc)(2) and (2) Pa-COD hydrolyzes the acetamide group of reducing end GlcNAc residue of (GlcNAc)(2). These findings indicate that GlcNAc-GlcN is produced from chitin by the cooperative hydrolytic reactions of both Pa-Chi and Pa-COD.
从日本千叶县习志野市八津干滩分离出的一株几丁质降解细菌菌株KN1699，被鉴定为副溶血性弧菌。用从KN1699培养物上清液制备的粗酶溶液处理几丁质粉末，得到一种二糖，β-D-N-乙酰葡糖胺基-(1,4)-D-葡糖胺（GlcNAc-GlcN），作为主要的几丁质降解产物。从粗酶溶液中分离出参与这种异二糖产生的细胞外酶，几丁质酶（Pa-Chi；分子量92 kDa）和几丁质寡糖脱乙酰酶（Pa-COD；分子量46 kDa），并阐明了它们的水解特异性。这些研究证实：（1）Pa-Chi水解几丁质产生(GlcNAc)₂；（2）Pa-COD水解(GlcNAc)₂还原端GlcNAc残基的酰胺基团。这些发现表明，GlcNAc-GlcN是由Pa-Chi和Pa-COD的协同水解反应从几丁质产生的。
