摘要
以Bacillus sp LS产生的壳聚糖酶粗酶液出发,经(NH4)2SO4盐析、DEAE-Sephadex A25阴离子交换、Sephadex G-100凝胶过滤分离纯化后,SDS-PAGE显示为一条带,测得其分子量为30.9k u。同时对其酶学性质进行了初步研究,发现该酶在低于40℃、pH6.0～7.5范围内较稳定,最适反应温度和pH值分别为55℃和5.0;Zn2+、Ag+、Ca2+、Co2+、Mn2+对该酶有明显的促进作用,而Fe3+、Hg2+对该酶有强烈的抑制作用;该酶的米氏常数为2.50 mg/mL,最大反应速度为4.19μmol/mL.min。
The chitosanase from Bacillus sp. LS is purified by ammonium sulfate fractionation, DEAE-Sephadex A25 ion-exchange chromatography and sephadex G-100 gel filtration. The purified enzyme is demonstrated by SDS-PAGE to be a homogeneous protein and the molecular weight is estimated as 30.9k u. The chitosanase was stable below 40℃ and within the pH range from 6.0-7.5. The optimal temperature for the enzyme was 55℃ and optimal pH was 5.0. Zn^2＋, Ag^＋, Ca^2＋, Co^2＋, Mn^2＋ enhance the enzyme activity, whereas Fe^3＋, Hg^2＋ inhibit the enzyme activity significantly. Kinetic parameter Km was 2.50 mg/mL, Vmax was 4.19 μmol/mL·min.
出处
《食品科技》
CAS
北大核心
2008年第2期4-7,共4页
Food Science and Technology
关键词
壳聚糖酶
纯化
性质
chitosanase
purification
properties
