壳聚糖修饰的PLGA纳米颗粒固定化碱性磷酸单酯酶的技术研究

Study on the Technology of CS-PLGA Nanospheres Immobilized Alkaline Phosphatase

以合成的壳聚糖修饰的乳酸-羟基乙醇酸共聚物(PLGA)为材料,戊二醛为交联剂,固定了在重组大肠杆菌中表达的碱性磷酸单酯酶,并通过单因素分析及正交试验探讨了酶固定化的最优条件。结果显示,在纳米颗粒质量分数50 mg、戊二醛体积分数4%、交联时间2.0 h、固定化时间9.0 h条件下,固定化酶的酶活回收率可达76.2%,同时固定化酶反应的最适温度、最适pH值及热稳定性酸碱稳定性得到了拓宽,从而为该酶的进一步应用奠定基础。

Alkaline phosphatase expressing in recombinant E.coli was immobilized on Chitosan-poly（lactic-co-glycolic acid） by using glutaraldehyde as cross-linking reagent.The immobilization conditions and characterization of the immobilized enzyme were obtained through single factor and orthogonal experiment.The results showed that the best condition of immobilization was optimal when the CS-PLGA nanoparticles concentration was 50 mg,the volume fraction of glutaraldehyde was 4%,cross-linked time was 2.0 h and immobilized time was 9.0 h,the immobilized enzyme can keep activity about 76.2%.At the same time the optimal temperature,the optimal pH,the thermal stability and pH stability of alkaline phosphatase were comparatively improved after immobilization.So it confirmed that the technology would form basis of the further application of immobilized alkaline phosphatase.