黑曲霉胞外β-葡萄糖苷酶的纯化及酶学性质的研究  

Purification of β-glucosidase from Aspergillus niger and its Enzymological Character

作　　者：徐星 肖华[1] 黄琳琳 别松涛[1] 

机构地区：[1]工业发酵微生物教育部重点实验室工业酶国家工程实验室天津市工业微生物重点实验室天津科技大学生物工程学院,天津300457

出　　处：《天津科技大学学报》2015年第5期15-19,共5页Journal of Tianjin University of Science & Technology

摘　　要：利用硫酸铵盐析、Superdex 200凝胶柱层析等步骤,从黑曲霉发酵液中纯化得到两种β–葡萄糖苷酶蛋白,其相对分子质量分别为1.15×105和7.0×104左右,比活力分别为62.1,U/mg（相对分子质量约为1.15×10^5）和53.0,U/mg（相对分子质量约为7.0×10^4）,纯化倍数分别为1.54和1.31,回收率分别为19.6%,和19.1%,β–葡萄糖苷酶最适水解p H为4.6,最适反应温度为50~55,℃.在p H 4.2~4.8、温度40~60,℃下均能保持稳定.Mn2＋、Mg2＋和K＋对β–葡萄糖苷酶有不同程度的激活作用,而Ca^2＋、Fe^3＋、Zn^2＋、Cu^2＋和Fe^2＋会抑制β–葡萄糖苷酶的酶活,Na＋和Ba2＋对β–葡萄糖苷酶活力影响不明显.以p NPG为底物时,该酶的Km和vmax分别为2.33,mmol/L与3.14,mmol/（L·min）.Two kinds of beta-glucosidase protein were separated and purified from Aspergillus niger through ammonium sulfate precipitation and Superdex 200 gel filtration chromatography. The enzyme molecular weights were about 1.15 × 10^5 and 7.0×10^4, which were identified by SDS-PAGE, The specific activities were 62.1 U/mg and 53.0 U/mg. And then they were purified to 1.54-fold and 1.31-fold with a recovery of 19.6% and 19.1%. The optimum reaction pH and temperature for beta-glucosidase were 4.6 and 50-55 ℃. The enzyme is stable in the pH value range of 4.2-4.8 and at the temperature be- tween 40 ℃ to 60 ℃. Mn^2＋, Mg^2＋ and K＋ have different degree of activation to the beta-glucosidase, while Ca^2＋, Fe^3＋, Zn^2＋, Cu^2＋ and Fe^2＋ can inhibit the activity of the beta-glucosidase. Na^＋ and Ba^2＋ have no obvious effect on the activity. The Km and vmax values of the enzyme are 2.33 mmol/L and 3.14 mmol/（L.min） respectively.

关 键 词：β–葡萄糖苷酶 分离纯化 黑曲霉 

分 类 号：Q814.1[生物学—生物工程]