交联青霉素G酰化酶聚集体制备及其催化特性研究

目的考察交联青霉素G酰化酶聚集体催化特性，探讨其应用潜力。方法以硫酸铵为沉淀剂获得青霉素G酰化酶蛋白沉淀，戊二醛交联沉淀的蛋白质制备交联酶聚集体，在此基础上研究交联酶聚集体的催化特性。结果交联粪产碱杆菌来源青霉素G酰化酶聚集体的最适反应温度55℃，最适pH9．0，其酸碱和热稳定性均优于游离酶，重复使用13批次几乎无酶活性丢失，反应20批次后仍有50．9％的活性。结论交联酶聚集体的稳定性较游离酶好，具有一定的工业应用前景。

Preparation of Cross-linked Penicillin G Acylase Aggregates and Its Catalytic Property

Objective Cross-linked enzyme aggregates （CLEA） have more advantages than carrier-bound immobilized enzymes. And this paper explored the potential application of cross-linked aggregates of penicillin G acylase by investigating its catalytic property. Methods The preparation of cross-linked aggregates about penicillin G acylase from Alcaligenesfaecalis was as follows： the enzyme was precipitated by ammonium sulfate and then was cross-linked with glutaraldehyde. Furthermore, its catalytic property was studied. Results The optimum reaction temperature and pH of the cross-linked penicillin G acylase aggregates were 55 ℃ and pH9.0. In addition, they had better thermal and pH stability than the free enzyme. The activity hardly lost after 13 cycles, and there was even 50.9% of the enzyme activity after 20 cycles. Conclusion The cross-linked penicillin G acylase aggregates have good operation stability and potential application as an industrial biocatalyst.