介孔材料的修饰及固定青霉素酰化酶的稳定性研究

利用扩孔剂的作用合成出较大孔径(12 nm)的介孔材料SBA-15, 并进行表面氨基修饰, 以此为载体, 以戊二醛为交联剂, 对青霉素酰化酶进行组装固定, 并对固定化青霉素酰化酶(PGA)的稳定性进行了深入的研究. 实验结果表明, PGA与载体交联后仍保持活性. 热稳定性研究结果表明, 制备的固定化青霉素酰化酶在低于60 ℃时保持稳定; pH在6~11范围内保持稳定; 固定化酶重复使用10次之后, 仍具有高达90%的残留活力.

Modification of Mesoporous Material and Stability of Immobilization of Penicillin G Acylase

Mesoporous materials of large pore size(12 nm)were synthesized by the usage of swelling agent.After modification,the mesoporous materials were used as the carriers in the immobilization of penicillin G acylase.Specifically,a study was carried out on the stability of the immobilized enzyme.Penicillin G acylase can catalyze the cleavage of the amide bond in the benzyl penicillin(penicillin G)side-chain to yield phenylacetic acid and 6-aminopenicillanic acid(6-APA).The enzyme is of great pharmaceutical importance,as the product 6-APA is the starting point for the synthesis of many semi-synthetic penicillin antibiotics.The activity of nature PGA is low,which limits the application of PGA.By immobilizing PGA on a solid support,it can be reused and its useful lifetime can be extended because the immobilized PGA is less susceptible to degradation,aggregation,or denaturation.The research results indicate that the functionalization of the internal surfaces of mesoporous solids permitted the enzyme immobilization.The reuse of the catalysts is also possible.The retention activity up to 90% of the PGA is observed in the most favorable case after using for 10 times.