[关键词]
[摘要]
环氧基团可以在温和条件下与酶分子的氨基发生共价结合使其固定于载体表面。选用含有活性环氧基团的甲基丙烯酸缩水甘油酯(GMA)为单体,N,N′-亚甲基双丙烯酰胺(MBAA)为交联剂,聚乙烯吡咯烷酮(PVP)为稳定剂,2,2′-偶氮二异丁腈(AIBN)为引发剂,乙醇水溶液为分散介质,并加入Fe3O4磁流体,通过反相悬浮聚合成功合成了大孔Ferrofluid-GMA-MBAA共聚物载体(FGM)。通过调节磁流体和交联剂用量,可调节载体比表面积,孔径以及溶胀性能。将葡萄糖氧化酶(GOD)偶联于GMA含量20%,磁流体含量4%,交联剂含量40%的共聚物载体4FGM (40),制成固定化葡萄糖氧化酶,其表观酶活高达546.23±2.33 U/g。讨论了固定化葡萄糖氧化酶的酶学性质,在最适条件(55 ℃,pH 8.0)下,固定化酶的表观酶活回收率为90.45%;连续使用15次活性仍接近初始值的60%;固定化酶在4 ℃保存30 d,活性保持不变。
[Key word]
[Abstract]
Oxirane groups can react with the amino groups of enzyme under mild conditions so that could be immobilized on the surface of copolymer supporter. The macroporous Ferrofluid-GMA-MBAA (FGM) polymer were synthesized by inverse suspension polymerization with glycidyl methacrylate (GMA) as the reactive monomer and N,N′-methylene-bis-acrylamide (MBAA) as the cross-linking agent. Polyvinylpyrrolidone (PVP) was used as the stabilizer monomer and azodiisobutyronitrile (AIBN) was used as the initiator monomer. Fe3O4 was added as magnetofluid to the dispersion medium, ethanol solution. The effects of the amount of magnetofluid and crosslinking agent on the structure properties and the apparent activity of immobilized enzyme were investigated. The recovery rate of apparent relative activity of 90.45% (about 546.23±2.33 U/g) was obtained when the glucose oxidase (GOD) enzyme was immobilized on FGM polymer [w (GMA) = 20%, w (ferrofluid) = 0.4%, w (MBAA) = 40%] at 55 ℃ and pH 8.0. The enzyme activity was nearly 60% of its initial even after being used for 15 times. After a 30-day storage at 4 ℃, the immobilized enzyme showed little changes in its activity.
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[基金项目]
国家高技术研究发展计划(863计划)(2012AA021504)