抗癌胚抗原单链抗体与核心链霉亲和素基因的融合及在大肠杆菌的表达  

Fusion and Expression of Genes Encoding Single-chain Antibody to Carcinoembryonic Antigen and Core-streptavidin

作　　者：杨卫东[1] 李彪[1] 朱承谟[1] 杨冠珍[2] 吴祥甫[2] 

机构地区：[1]上海第二医科大学附属瑞金医院，上海 200025 [2]中国科学院上海生物化学研究所，上海 200031

出　　处：《上海免疫学杂志》2000年第6期333-336,共4页Shanghai Journal of Immunology

基　　金：国家自然科学基金(39770231);上海市启明星计划(98Q14011)资助项目

摘　　要：制备抗癌胚抗原 (CEA )单克隆抗体的单链抗体 ,在保留抗原抗体结合位点的同时有效降低抗体的分子量不仅可减少人抗鼠抗体反应 (HAMA ) ,而且适合放射免疫显像。为纯化及核素标记抗体 ,将单链抗体基因与核心链霉亲和素基因融合并在大肠杆菌得到高效表达 ,表达量占菌体总蛋白的 2 4%。SDS PAGE和蛋白质印迹图谱显示表达产物分子量为 41kD ,与其基因编码蛋白质的理论推算值相符。表明融合蛋白能特异性地与生物素结合 ,RIA表明表达产物具有结合其特异性抗原CEA的能力 ,以HRP标记的生物素作为抗体进行蛋白质印迹在 41kD处可见表达条带。说明表达物不仅能与生物素结合且能特异性地与CEA结合。In the course of preparing the single chain monoclonal antibodies to carcinoembryonic antigen(CEA),the effective reduction of molecular weight of the antibodies with retention of the antigen antibody conbining sites can not only reduce the incidence of human anti mouse antibody(HAMA) reaction,but also are suitable for the radioimmunoimmaging In this study,the genes encoding single chain antibody to CEA were linked to core streptavidin gene in order to facilitate purification and radioisotope labeling,and the fused genes were expressed in E coli at high lever,accounting up to 24% of the total bacterial proteins The molecular weight of the expressed products as characterized by SDS PAGE and Western blots was 41kD As shown from RIA,the expressed products processed the ability to bind with specific antigen CEA Using horseradish peroxidase(HRP) labeled biotin as antibody in Western blots,only the 41kD band could be detected,indicating that the fused protein not only had the ability to bind with CEA,but also could bind biotin specifically

关 键 词：癌胚抗原 单链抗体 链霉亲和素 基因表达 

分 类 号：R730.3[医药卫生—肿瘤]