包埋-交联磷脂酶A_1聚集体的制备及酶学性质

Preparation of Encapsulation-crosslinked Aggregates of Phospholipase A_1

为得到可重复使用且活力较高的固定化磷脂酶A1,采用包埋-交联酶聚集体的方法对磷脂酶A1进行固定,对固定化条件和部分酶学特性进行优化和研究,确定最佳条件为:酶液质量浓度0.06g/mL、沉淀剂饱和度80%、沉淀pH6、沉淀时间35min、戊二醛体积分数0.4%、交联时间6.5h、海藻酸钠质量分数2%、Ca2+浓度0.25mol/L。得到包埋-交联磷脂酶聚集体A1的酶活回收率为80.2%。固定化酶热稳定性增强,重复使用7次相对酶活力保留在6 5%以上。

In order to prepare reusable immobilized phospholipase A1 with high activity, the encapsulation-crosslinked aggregate method was used. The immobilization conditions and partial properties of immobilized phospholipase were determined. Results indicated that the optimal preparation conditions were enzyme concentration of 0.06 g/mL, precipitant saturation degree of 80%, precipitation time of 35 min, glutaradehyde concentration of 0.4%, cross-linking time of 6.5 h, sodium alginate concentration of 0.2% and Ca^2＋ concentration of 0.25 mol/L. Under the optimal preparation conditions, the recovery rate of enzyme activity was 80.2%. The thermal stability of immobilized phospholipase was better than that of free phospholipase. Meanwhile, after seventh repeated use, the relative activity of immobilized phospholipase still remained more than 65%.