摘要
研究了来源于曲霉No.5.1的β_葡萄糖苷酶的纯化和酶学性质。粗酶液经硫酸铵沉淀、DEAE-chitopearl和Sephadex G-100柱层析得到纯β_葡萄糖苷酶,SDS-PAGE凝胶电泳显示一条带,测得分子量为67.5 kD。该酶最适反应pH6.0,最适反应温度为60℃,在80℃以下、pH3.0～9.0酶活力相对稳定。K^＋、Na^＋、Mg^2＋和Zn^2＋对酶有激活作用,而Ag^＋和Fe^2＋对酶具有明显的抑制作用。该酶对纤维二糖和水杨素的水解能力最强,水解水杨素的Km值为3.09 mmol/L。
The factors affecting Aspergillus niger No.5.1 for β_glucosidase purification and enzyme properties have been investigated.β_glucosidase was purified to electrophoretic homogeneity by using ammonium sulfate precipitation,DEAE-chitopearl and Sephadex G-100 chromatography.Its molecular weight was estimated to be about 67.5 kD by SDS-PAGE.The enzyme showed optimal activity at pH 6.0 and 60 ℃.It was stable in pH 3.0～9.0 and under 80 ℃.The β-glucosidase activity was significantly inhibited by Ag^＋ and Fe^2＋ and stimulated by K^＋,Na^＋,Mg^2＋,Zn^2＋,respectively.The enzyme hydrolyzed cellobiose and salicin more efficiently than other substrates.Its michaelis constant for hydrolysis of salicin was 3.09 mmol/L.
出处
《江西农业大学学报》
CAS
CSCD
北大核心
2008年第3期521-524,共4页
Acta Agriculturae Universitatis Jiangxiensis
基金
江西省自然科学基金(0620071)
江西省教育厅科技项目(赣教技字[2007]168号)
航空高校基金(EA200502138)资助
关键词
β_葡萄糖苷酶
曲霉
纯化
酶学性质
β-glucosidase,aspergillus niger,purification,enzyme properties
