嗜热毛壳菌一种β-葡萄糖苷酶的分离纯化及特性  

Purification and properties of β-glucosidase from Chaetomium thermophilum

作　　者：滕芳超[1] 李多川[1] 李亚玲[1] 李浙江[1] 

机构地区：[1]山东农业大学环境生物系,泰安271018

出　　处：《菌物学报》2006年第3期481-487,共7页Mycosystema

基　　金：国家863计划资助项目(2003AA241162);国家自然科学基金资助项目(3017001330270013)

摘　　要：研究了嗜热毛壳菌Chaetomium thermophilum 液体发酵产生的一种胞外β-葡萄糖苷酶的分离纯化及特性.粗酶液经硫酸铵沉淀、DEAE-Sepharose Fast Flow 阴离子层析、Phenyl-Sepharose 疏水层析、Sephacryl S-100 分子筛层析等步骤后获得凝胶电泳均一的β-葡萄糖苷酶.经10%SDS-PAGE 和凝胶过滤层析方法分别测得该酶的分子量大小约为118.0kDa 和120.1kDa.该酶反应的最适温度为70℃, 最适pH 值为4.0～5.0.有高的热稳定性,在60℃保温1小时酶活性不丧失,在70℃时的半衰期为16min,在90℃保温10min仍具有7.6%的活性.且能在pH 4.0～11.0 之间保持稳定.金属离子对β-葡萄糖苷酶的活性影响较大, 其中 Ca2＋、Ba2＋对酶有激活作用, 而Zn2＋ 、Cu2＋、Al3＋、Ag＋、Hg2＋对酶有显著的抑制作用.β-Glucosidase is an important component of the cellulase complex. It not only hydrolyzes cellobiose and short-chain cellooligosaccharides to glucose, but also removes the inhibitory effect of cellobiose on the 13-1, 4-endoglucanase and exoglucanase, thereby increasing the overall rate of cellulose biodegradation. 13-Glucosidase from culture supernatant of a thermophilic fungus Chaetomium thermophilum was purified to homogeneity, by using ammonium sulfate fraction, DEAE-sepharose fast flow chromatography, phenyl-sepharose fast flow chromatography and sephacryl S-100 chromatography, and its properties were studied. The molecular mass of the enzyme is about between ll8.0kDa to 120.1kDa, as identified by 10% SDS-PAGE and gel filtration correspondingly. Its optimum pH value and temperature are 4.0-5.0 and 70℃ respectively. It is stable in pH 4.0-11.0 and under 60℃. Different metal ions show different effects on the 13-glucosidase activity. Ca^2＋ and Ba^2＋ will enhance its activity, while Zn^2＋, Cu^2＋, A1^3＋, Ag^＋ and Hg^2＋ will cause obvious inhibition.

关 键 词：嗜热真菌 酶分子量 最适温度 最适PH值 

分 类 号：Q936[生物学—微生物学]