白头翁皂苷H3糖苷酶的分离纯化及酶性质

Isolation and properties of pulchinenoside H3 glycosidase

对Absidiasp.P39r所产白头翁皂苷H3糖苷酶进行了分离纯化,得到了电泳纯的酶蛋白,并对其性质做了进一步研究。结果表明,该酶分子质量约为40ku;最适反应温度为40℃,最适反应pH为5.0;在pH 4.0-7.0,温度低于40℃条件下具有相对稳定的酶活力;金属离子Na＋、K＋、Mg2＋对酶反应无显著影响,而Fe3＋、Cu2＋、Zn2＋对其有较强的抑制作用;米氏常数为17.01mmol/L,最大反应速度为0.38mmol/（L·min）。

Glycosidase capable of degrading pulchinenoside H3 fromAbsidia sp.P39 rwas purified and characterized.The results showed that its molecular weight was 40 ku,and the maximal activity was obtained at pH 5and 40 ℃ and stable at pH 4.0-7.0and 40 ℃.Ions of Fe3＋,Cu2＋,Zn2＋inhibit glycosidase but Na＋,K＋,Mg2＋had no effect on the activity.The maximum reaction rate was0.38mmol/（L·min）and Kmwas 17.01mmol/L.