Izume M, Nagae S, Kawagishi H, Mitsutomi M, Ohtakara A
Katakura Chikkarin Co., Ltd., R&D Center, Ibaraki, Japan.
Biosci Biotechnol Biochem. 1992 Mar;56(3):448-53. doi: 10.1271/bbb.56.448.
The hydrolyzate of partially N-acetylated chitosan by Bacillus sp. No. 7-M chitosanase was separated by gel filtration on Bio-Gel P-2. Sugar compositions and sequences of the oligosaccharides were identified by exo-splitting with beta-GlcNase, fast atom bombardment mass spectroscopy, and proton NMR spectroscopy. In addition to chitooligosaccharides, (GlcN)2, (GlcN)3, and (GlcN)4, hetero-chitooligosaccharides such as (GlcN)2.GlcNAc.(GlcN)2, GlcN.GlcNAc.(GlcN)3, (GlcN)2.GlcNAc.(GlcN)3, and GlcN.GlcNAc.(GlcN)4 were detected. These results indicate that Bacillus sp. No. 7-M chitosanase is absolutely specific toward the GlcN.GlcN bonds in partially N-acetylated chitosan and at least three GlcN residues were necessary to the hydrolysis of chitosan by chitosanase.
通过芽孢杆菌属7-M壳聚糖酶对部分N-乙酰化壳聚糖进行水解，水解产物经Bio-Gel P-2凝胶过滤分离。通过β-葡萄糖胺酶外切裂解、快原子轰击质谱和质子核磁共振光谱对寡糖的糖组成和序列进行鉴定。除了壳寡糖、（葡糖胺）2、（葡糖胺）3和（葡糖胺）4外，还检测到了杂合壳寡糖，如（葡糖胺）2·N-乙酰葡糖胺·（葡糖胺）2、葡糖胺·N-乙酰葡糖胺·（葡糖胺）3、（葡糖胺）2·N-乙酰葡糖胺·（葡糖胺）3和葡糖胺·N-乙酰葡糖胺·（葡糖胺）4。这些结果表明，芽孢杆菌属7-M壳聚糖酶对部分N-乙酰化壳聚糖中的葡糖胺-葡糖胺键具有绝对特异性，并且壳聚糖酶水解壳聚糖至少需要三个葡糖胺残基。
