两性离子聚合物的制备及其对酶活性的影响

摘要

以具有生物相容性的羧基甜菜碱甲基丙烯酸酯(CBMA)为单体、过硫酸铵为引发剂、亚硫酸钠为还原剂,采用自由基聚合工艺制备了羧基甜菜碱两性离子聚合物PCBMA,并对其进行核磁氢谱和凝胶渗透色谱表征,结果显示聚合物具有预期结构.进一步以葡萄糖氧化酶(GOD)为模型酶,分别制备了添加和未添加聚合物PCBMA的GOD溶液,在四种不同温度下探究酶的活性与时间的关系.结果表明,添加PCBMA的GOD在65℃条件下经过12h后,其活性浓度是对照样GOD 1h时活性浓度的103％;未添加PCBMA的对照样12h后GOD活性浓度仅为1h时的35％.羧基甜菜碱两性离子聚合物能够有效地维持酶的活性,并且温度越高聚合物对酶活性维持的效果越明显.%The carboxyl betaine zwitterionic polymer (PCBMA) was synthesized by free radical polymerization,the biocompatible zwitterionic carboxybetaine methacrylate (CBMA) as monomer,ammonium persulfate as initiator and sodium sulfite as a reductant.The results of 1H NMR and GPC indicated that the polymer has expected structure.As a model enzyme,the glucose oxidase (GOD) was prepared with and without PCBMA to investigate the relationship between the activity of GOD and time under different temperatures.The results showed that the activity concentration of GOD with PCBMA at 65℃ after 12h was 103％ of that without PCBMA for lh,whereas the GOD activity of control after 12h was only 35％ of that without PCBMA for 1h.The carboxyl betaine zwitterionic polymer could effectively maintain the enzyme activity,and this effect was more evident as the temperature increases.