壳聚糖酶的分离纯化及其特性研究

Study on Separation and Purification of Chitosanase and Its Characteristics

通过硫酸铵分级盐析、Sephadex G-25凝胶过滤层析、DEAE Cellulose 52离子交换层析,将曲霉TCCC45017产的壳聚糖酶进行纯化,纯化倍数为57.21,回收率为26.55%,比活力提高至587.55 U/mg.经过SDS-PAGE电泳测得其分子质量为3.75×104 u.该酶作用的最适温度为55℃,最适pH为5.5,50℃以下保温1 h内酶的热稳定性较好,pH稳定范围为5.5～7.0,添加金属离子Mg2+、Ca2+、Ba2+、Mn2+对该酶有激活作用,Cu2+、Fe2+、Zn2+、Al3+则对酶有抑制作用.

The chitosanase from Aspergillus TCCC45017 was purificated by ammonium sulfate precipitation,Sephadex G-25 gel filtration and ion-exchange chromatography（DEAE Cellulose 52）.The chitosanase activity and recovery rates were 57.12-fold and 26.55% respectively.The specific activity reached 587.55 U/mg.The purified enzyme was demonstrated by SDS-PAGE to be a homogeneous protein,and its molecular weight was 3.75×104 u.The optimal temperature for the enzyme was 55 ℃ and optimal pH was 5.5,it was stable below 50 ℃ with one hour and within pH range of 5.5-7.0.Mg2＋,Ca2＋,Ba2＋,Mn2＋ enhanced the enzyme activity,whereas Cu2＋,Fe2＋,Zn2＋,Al3＋ inhibited the enzyme activity.