一株嗜热毛壳菌β-葡萄糖苷酶的分离纯化及特性  

PURIFICATION AND PROPERTIES OF β-GLUCOSIDASE FROM THERMOPHILIC CHEATOMIUM THERMOPHILE

作　　者：楚春雪[1] 李多川[1] 郭润芳[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》2004年第3期397-402,共6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(30170013 30270013)

摘　　要：研究了液体发酵嗜热毛壳菌Chaetomium thermophile产生的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12.5%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78.4kDa和81kDa。该酶反应的最适温度和pH值分别为60℃和4.5-5.0。有较好的酸稳定性和热稳定性。金属离子对β-葡萄糖苷酶的活性影响较大, 其中Ca2+对酶有激活作用, 而Ag+、Cu2+ 、Hg2+对酶有显著的抑制作用。该酶对水杨苷具有很强的底物特异性。glucosidase is an important component of the cellulase complex. It not only hydrolyzes oligosaccharides to glucose cellobiose, but also removes the inhibitory effect of cellobiose on the -1, 4-endoglucanase and exoglucanase, thereby increasing the overall rate of cellulose biodegradation.β-glucosidase from culture supernatant of a thermophilic fungus Cheatomium thermophile 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 and substrate specificities were studied. The molecular mass of the enzyme is about between 78.4kDa to 81kDa, as identified by 12.5% SDS-PAGE and gel filtration correspondingly. Its optimum pH value and temperature are 4.5-5.0 and 60℃ respectively. It has thermostable and aciduric activity , then will remain 20% after 15min at 80℃. Different metal ions show different effects on the -glucosidase activity. Ca2+ will enhance its activity , while Ag+, Cu2+, Hg2+ will cause obvious inhibition. The enzyme acts specially on salicin.

关 键 词：Β-葡萄糖苷酶 分离 纯化 嗜热真菌 嗜热毛壳菌 水杨苷 

分 类 号：Q936[生物学—微生物学]