磁性高分子微球共价结合中性蛋白酶

Immobilization of a Neutral Protease onto a Magnetic Polymer Microsphere by Covalent Coupling

磁性高分子微球内含磁核，外部是表面带羧基的聚苯乙烯高分子外壳，不仅可以共价偶联酶分子，而且易于磁场分离，是固定化酶的理想载体。采用碳化二亚胺法，在磁性高分子微球上固载ＡＳ１．３９８中性蛋白酶，制备活性达７００Ｕ／ｇ的磁性固定化中性蛋白酶，缓冲液的ｐＨ６．０、离子强度较高时，磁性固定化酶（ＭＩＥ）的活性最高。载体性质对ＭＩＥ活性影响很大，磁性微球粒径愈小，表面羧基含量愈大，ＭＩＥ活性愈高。

A neutral protease from Bacillus subtilis has been immobilized onto a magnetic polystyrene microsphere havig surface carboxyl groups by covalent coupling. The magnetic immobilized neutral protease, having 700U/g enzyme activity, has benn prepared. The magnetic immobilized neutral protease will show optimum activity when a neutral protease is immobilized onto a magnetic microsphere at pH 6. 0 and high ionic strength. With the diameter of magnetic microspheres decreasing and surface carboxyl groups of magnetic microspheres increasing,magnetic immobilized neutral protease activity will increase.