参环毛蚓肠道内源性纤维素酶的分离纯化及酶学性质分析  

Seperation,purification and Enzymatic properties of endogenous cellulase from the gut of Pheretima aspergillum

作　　者：胡亚冬[1,2] 谢春芳[1] 张琰[1] 姚冬生[1] 

机构地区：[1]暨南大学生命科学技术学院微生物技术研究所,广东广州510630 [2]广州科仁生物工程有限公司,广东广州510600

出　　处：《暨南大学学报（自然科学与医学版）》2010年第1期89-94,共6页Journal of Jinan University(Natural Science & Medicine Edition)

基　　金：广东省科技攻关计划项目(2005B20601004)

摘　　要：通过对参环毛蚓肠道组织提取液进行DEAE阴离子交换及凝胶过滤层析，获得参环毛蚓单一的内源纤维素酶的活性组分．根据AlpHaEaseFC^TM软件计算出该组分分子质量约为45ku，命名为Cxl．羧甲基纤维素钠（sodium carboxymethylcellulose，CMC）法对Cxl进行酶学性质分析．分析结果显示：对于底物羧甲基纤维素钠，Cxl的米氏常数（Km）为0．289mg/mL，Vmax为0．446U·mL^-1·min^-1，反应最适温度为55℃，最适pH为6．0，在40～60℃、pH5．0～8．0具有较好的热稳定性和pH稳定性，其相对酶活力都能保持在55％以上．Ag^＋和Ba^2＋对Cxl起显著激活作用，K^＋、Zn^2＋、Mg^2＋、Ca^2＋、NH^4＋、Ni^2＋、Na^＋、Pb^2＋部分抑制酶活性，Cu^2＋离子对Cxl有完全抑制作用，而Fe^2＋对酶活力无明显影响．The endogenous cellulase from the gut of Pheretima aspergillum by homogenization was separated by DEAE anion exchanger and gel filtration chromatography, and a single band with cellulase activity was identified by SDS-PAGE and zymography. Its molecular mass was about 45 ku as calculated by AlpHaEaseFCTM software and this cellulase was named Cxl. The results of its enzymatic properties using sodium carboxymethylcellulose （CMC） as the substrate showed that its Km was 0. 289 mg/mL and its Vmax = was 0. 446 U . mL^-1. min^-1 Its optimum reaction temperature and pH value were 55 % and pH 6.0, respectively. The enzyme was stable over a broad temperature （40 - 60 ℃ ） and pH （5.0 - 8.0） range. Under these conditions, the levels of enzymatic activity could be retained above 55 %. Moreover, it was found that the enzyme was dramatically activated by Ag ^＋ and Ba^2＋ , completely inactivated by Cu^2＋ and partially by many other metal ions, such as K^＋, Zn^2＋, Mg^2＋, Ca^2＋, NH^4＋, Ni^2＋, Na^＋ and Pb^2＋, while Fe^2＋ showed no effect on the reaction.

关 键 词：参环毛蚓 纤维素酶 纯化 酶学性质 

分 类 号：Q556.2[生物学—生物化学]