仿生硅化固定化胰蛋白酶用于控制生物粘泥的研究

摘要

目的:采用仿生硅化法实现对胰蛋白酶的固定,并将固定化酶与聚甲基丙烯酸甲酯(PMMA)相结合用于抗生物粘泥复合膜的制备.方法:研究了正硅酸甲酯(TMOS)与酶的浓度比、介孔氧化硅(MPS)与酶的质量比、有机溶剂等因素的影响.并以MPS固定化酶为对照实验,对复合膜酶的稳定性、催化活性、重复使用性、抗蛋白质吸附性能等进行了分析.结果:通过仿生硅化法制备的仿生氧化硅-酶-聚甲基丙烯酸甲酯复合膜(SiO2-Enzyme-PMMA film),与介孔氧化硅-酶-聚甲基丙烯酸甲酯复合膜(MPS-Enzyme-PMMA film)相比,具有更好的稳定性,在25℃和50℃储藏30 d后,两种膜酶活性分别为86.3％和81.2％.SiO2-Enzyme-PMMA film在重复使用6次之后,复合膜的酶活剩余89.1％.将复合膜浸泡在牛血清白蛋白(BSA)溶液中18d后,其表面蛋白质吸附量仅为不合酶PMMA的三分之一.两种复合膜均具有良好的抗蛋白吸附性能.结论:仿生硅化制备固定化酶,与介孔氧化硅载体相比,在提高固定化酶的包埋率和稳定性方面有更显著的优势,其条件温和,操作简便,活性高,应用于抗生物粘泥涂层具有更好的防污效果.%Objective:Trypsin was immobilized on the SiO2 by biomimetic silicification process.The catalytic films were prepared by suspending the immobilized trypsin directly into a poly(methyl methacrylate) solution in toluene.Methods:The concentration ratio of TMOS and enzyme,mass ratio of MPS and enzyme and the type of organic solvents were studied.Compared with mesoporous silica (MPS) immobilized enzyme,the storage stability of the composite films,catalytic activity,reusability,and resistant to protein adsorption properties was studied.Results:The results indicated that the SiO2-Enzyme-PMMA film showed the better stability.After 30 days,the residual activity of SiO2-Enzyme-PMMA film and MPS-Enzyme-PMMA film were 86.3％ and 81.2％ of the initial activity,respectively.The SiO2-Enzyme-PMMA film also showed good operational stabilities in six times of continuous operations.The enzyme residual activity was 89.1％.The surface protein adsorption capacity of SiO2-Enzyme-PMMA film immersed in BSA solution for 18 days was only 1/3 of the PMMA film without enzyme.The two films both had good adsorption properties resistant to protein.Conclusion:Compared with the mesoporous silica carrier,SiO2 prepared by biomimetic silicification process had higher stability and embedding rate.The method had the advantages of mild condition,simple operation and high activity,and can be used in the anti fouling coating.