【作者】 严钦； 周伟； 李幸慰； 冯美卿； 周珮；

【Author】 Qin Yan;Wei Zhou;Xingwei Li;Meiqing Feng;Pei Zhou;School of Pharmacy,Fudan University;

【机构】 复旦大学药学院；

【摘要】 从拟青霉菌sp.229中分离纯化得到一种能将人参皂苷Rb1专一性转化为人参皂苷Rg3的β-葡萄糖苷酶。该酶的分子量约为305KDa,由三个分子量约为102KDa的相同亚基组成。在pH3.5和55℃酶具有最佳的反应活性,在pH3⁷和温度不高于50℃时酶保持相对稳定。Mg²⁺和Ni²⁺对酶反应有较强的抑制作用,而Fe²⁺则对该酶具有明显的活化作用。该酶的最佳反应底物为p-硝基苯酚-β-葡萄糖苷（pNPβG）,同时对人参皂苷Rd和人参皂苷Rb1具有很强的反应活性。人参皂苷Rb1在该酶的催化反应下,其水解路径为Rb1→Rd→Rg3。更多还原

【Abstract】 A ginsenoside-β-glucosidase that hydrolyzes ginsenoside Rb1 to ginsenoside Rg3 was successfully purified to homogeneity from a newly isolated Paecilomyces Bainier sp.229.The purified enzyme,with a native molecular mass estimated to 305 KDa,was composed of three identical subunits of about 102 KDa.The optimal enzyme activity was observed at pH 3.5 and 55℃.It was stable within pH 3-7and at temperatures lower than 50℃.The enzyme was most inhibited by Mg²⁺ and Ni²⁺,and was obviously activated by Fe²⁺.The optimal substrate for the enzyme was p-nitrophenyl-β-D-glucoside（pNPβG）,followed by ginsenoside Rd,ginsenoside Rb1.The hydrolyzing pathway of ginsenoside Rbl by the enzyme was Rb1→Rd→Rg3.更多还原