SMA基微孔膜固定化β-半乳糖苷酶的研究  

Immobilization of β-galactosidase by the SMA Modified PVDF Membrane

作　　者：李咏兰[1] 邱广亮[1] 陈香君[1] 门泉渌 邱广明[3] 

机构地区：[1]内蒙古师范大学生物工程研究中心,呼和浩特010022 [2]甘肃省医疗器械检测中心,兰州730030 [3]内蒙古工业大学电力学院,呼和浩特010051

出　　处：《中国生物工程杂志》2008年第10期66-71,共6页China Biotechnology

基　　金：国家自然科学基金资助项目(50066002)

摘　　要：以超临界二氧化碳(SCCO2)为分散介质在聚偏氟乙烯(PVDF)微孔膜表面和孔内进行马来酸酐和苯乙烯的接枝共聚,合成出超高分子量的苯乙烯/马来酸酐交替共聚物(SMA)基微孔PVDF膜。以SMA基PVDF膜为载体通过酸酐基和酶分子上的氨基偶联,制备出具有酶催活性的功能性分离膜。考察了影响酶固定化的因素,确定其最佳固定化条件为:温度,4℃;pH,8.2;酶/膜,1:10;反应时间,6h。固定化酶膜的最适温度为55℃,最适pH为7.8,均比自由酶稍高;Km(0.3mmol/L)与自由酶接近。固定化酶膜活力达13.5U/cm2膜,比活为280.0U/mg蛋白,蛋白载量为68.2μg/cm2膜,相对活力为89.0%。固定化酶膜表现出良好的操作稳定性和储存稳定性,SMA基PVDF微孔酶膜超滤制备低乳糖牛奶实验表明该技术应用前景广阔。The SMA modified PVDF membrane were prepared by the copolymerization of styrene with maleic anhydride on the surface of PVDF membrane in the supercritical carbon dioxide. Free β-galactosidase was immobilized on the membranes by the formation of amido bonds between the amino groups of the enzyme and the anhydrides on the surface of the membranes. The effects of immobilization on the properties of the immobilized β- galactosidase were studied. The immobilized membrane showed the highest activity when β-galactosidase was immobilized for 6h under the condition of pH 8. 2, 4℃, and enzyme/membrane 1 ： 10. The activity of immobilized enzyme and protein binding capacity reached 13.5U and 68. 2μg/cm2 membrane. The specific activity of immobilized enzyme could reach 280.0U/mg protein. The relative activity was 89.0% , compared with the free β-galactosidase. The immobilized enzyme had higher optimum temperature （55℃） and pH （7. 8 ） compared with that of free β-galaetosidase and showed excellent operational and storage stability.

关 键 词：SMA基PVDF膜 Β-半乳糖苷酶 固定化 

分 类 号：Q814.2[生物学—生物工程]