亲水性交联聚合物载体的合成及其固定化青霉素酰化酶

Synthesis of Hydrophilic Macroporous Copolymer and its Application as Support of Immobilizing Penicillin G Acylase

选用含环氧基团的甲基丙烯酸缩水甘油酯(GMA)和亲水性的N-乙烯吡咯烷酮(NVP)单体,以N,N′-亚甲基双丙烯酰胺(MBAA)为交联剂,甲酰胺作致孔剂,通过反相悬浮聚合技术成功合成了一系列大孔、珠状GMA-NVP-MBAA三元共聚物载体.N-乙烯吡咯烷酮介入共聚物体系,使共聚物载体具有较强的亲水性,有利于青霉素酰化酶的固定化.通过调节交联剂的用量和单体NVP与GMA的比例,可以调节共聚物载体的孔结构与表面性能.用合成的平均孔径为15.7nm、表面环氧基含量1.11mmol·g-1亲水性珠状载体固定青霉素酰化酶,固定化酶水解青霉素G钾盐的活性达491U·g-1;在4℃保存30d,活性保持不变.经4次使用后活性达到稳定(444U·g-1),再经14次使用后,活性没有明显变化.

A series of the macroporous beaded glycidyl methacrylate (GMA) \|N\|vinyl\|2\|pyrrolidone (NVP) \|N, N′\|methylene\|bis\|(acrylamide) (MBAA) copolymers (GNM) were synthesized with formamide as pore generating agent by inverse suspension polymerization and used as the support for the immobilization of penicillin G acylase. The effects of the amount of crosslinking agent and the ratio of NVP/GMA on the structure properties and apparent activity of the immobilized enzyme were investigated. The specific surface area of GNM copolymer increases but its average pore diameter and pore volume decrease with increasing the amount of crosslinking agent. The activity of enzyme immobilized on GNM was about 491 U·g\+\{-1\}, when the polymer was synthesized at w (NVP)/w (GMA) = 1/10 with 50%(wt) crosslinking agent having a mean pore diameter of 15.7 nm and an oxirane group content of 1.11mmol/g. After the immobilized enzyme had been kept at 4 ℃ for 30 days, no any change of the activity could be found. When the immobilized enzyme was used repeatedly to hydrolysis penicillin G for 4 times, the activity reached the relatively steady value (444 U·g\+\{-1\}) from 491 U·g\+\{-1\}, then it was used continuously for 14 times, its activity was hardly changed.