微生物产大豆异黄酮糖苷酶分离纯化的研究

Purification of Soybean Isoflavone-glucosidase Produced by Microorganisms

利用离子交换层析法分离纯化了由菌种Absidia sp.SI39d发酵所产的1种高活性大豆异黄酮糖苷酶,经SDS-聚丙烯酰胺凝胶电泳检验得到电泳单点的纯酶,并对其酶性质进行了研究。提纯酶的活力达173U/ mL,酶蛋白的分子量为61ku,最适反应温度为40℃,最适pH值为5.0,在20～60℃,pH4.0～7.0之间酶活力相对稳定。Co^(2+)、Ca^(2+)、Zn^(2+)对酶活性无影响;Ag^+、Cu^(2+)对酶活性有抑制作用;C_([Fe^(3+)])<50mmol/L时,对酶活性无影响;当C_([Fe^(3+)])>50mmol/L时,有抑制作用。该酶的酶反应动力学方程为V=2.07[s]/(1.45+[s])。

The Isoflavone-glucosidase from Absidia sp. SI39d strain was purified by a DEAE-Cellulose column. The enzyme activity is 173U/mL, and its molecular weight is 61ku in the SDS-polyacrylamide gel electrophoresis. The optimum reaction conditions for the enzyme are 50℃, pH 5.0. Under the conditions of temperature 20-60℃, pH 5.0-7.0, the enzyme is stable. Co^2＋ , Ca^2＋ and Zn^2＋ ions hardly had any effect on isoflavone glycosidase activity, while Ag^＋ and Cu^2＋ inhibited enzyme activity. The michaelis equation obtained in this paper is V=2.07[s]/（1.45＋[s]）.