Fukamizo T, Ohkawa T, Ikeda Y, Goto S
Laboratory of Biophysical Chemistry, Faculty of Agriculture, Kinki University, Nara, Japan.
Biochim Biophys Acta. 1994 Apr 13;1205(2):183-8. doi: 10.1016/0167-4838(94)90232-1.
Partially (25-35%) N-acetylated chitosan was digested by chitosanase from Bacillus pumilus BN-262, and structures of the products, partially N-acetylated chitooligosaccharides, were analyzed in order to investigate the specificity of the chitosanase. The chitosanase produced glucosamine (GlcN) oligosaccharides abundantly, indicating that the chitosanase splits the beta-1,4-glycosidic linkage of GlcN-GlcN. The chitosanase also produced hetero-oligosaccharides consisting of glucosamine and N-acetyl-D-glucosamine (GlcNAc). Three types of the hetero-oligosaccharides purified by cation-exchange chromatography and HPLC were found to have GlcNAc residue at their reducing end and GlcN residue at their non-reducing end, indicating that the chitosanase can also split the linkage of GlcNAc-GlcN. The determination of the mode of action toward partially N-acetylated chitosan enables a classification of chitosanases according to their specificities and a more precise definition of chitosanases.
用短小芽孢杆菌BN-262产生的壳聚糖酶消化部分（25%-35%）N-乙酰化壳聚糖，并对产物部分N-乙酰化壳寡糖的结构进行分析，以研究该壳聚糖酶的特异性。该壳聚糖酶大量产生氨基葡萄糖（GlcN）寡糖，表明该壳聚糖酶能切断GlcN-GlcN的β-1,4-糖苷键。该壳聚糖酶还产生由氨基葡萄糖和N-乙酰-D-葡萄糖胺（GlcNAc）组成的杂合寡糖。通过阳离子交换色谱和高效液相色谱纯化的三种杂合寡糖在其还原端有GlcNAc残基，在其非还原端有GlcN残基，这表明该壳聚糖酶也能切断GlcNAc-GlcN的连接。确定壳聚糖酶对部分N-乙酰化壳聚糖的作用方式，能够根据壳聚糖酶的特异性对其进行分类，并对壳聚糖酶进行更精确的定义。
