抗癌胚抗原嵌合重链与核心链霉亲和素基因的融合及表达  

Fusion and Expression of the Genes Encoding Murine Human Chimeric Heavy Chain to Carcinoembryonic Antigen with Core streptavidin Gene

作　　者：杨卫东[1,2] 李彪[1] 朱承谟[1] 廖文韬[3] 杨冠珍[3] 吴祥甫[3] 

机构地区：[1]上海第二医科大学瑞金医院 [2]中国科学院上海生物化学研究所,上海200031 [3]中国科学院上海生物化学研究所

出　　处：《生物化学与生物物理学报》2000年第1期55-58,共4页

基　　金：国家自然科学基金;上海市启明星计划资助

摘　　要：将抗癌胚抗原（ＣＥＡ）单克隆抗体的重链可变区与人的恒定区（Ｃγ３） 连接， 制备抗癌胚抗原嵌合重链用于放免治疗及其他导向治疗， 可减少人抗鼠抗体反应（ＨＡＭＡ） 。为纯化及核素标记抗体， 将嵌合重链基因与核心链霉亲和素基因融合。融合基因在大肠杆菌得到高效表达， 表达量占菌体总蛋白的２４ ％ 。ＳＤＳＰＡＧＥ 和蛋白质印迹图谱显示表达产物分子量为７０ ｋＤ， 与其基因编码蛋白质的理论推算值相符。以ＨＲＰ标记的生物素作为抗体进行蛋白质印迹， 在７０ ｋＤ 处可见表达条带， 表明融合蛋白能特异性地与生物素结合， 使嵌合重链经生物素柱进行廉价纯化成为可能。表达产物在胞内主要以不溶性的包含体存在， 经变性和复性处理后， ＲＩＡ 表明表达产物具有结合其特异性抗原ＣＥＡ的能力。In order to reduce the human anti murine antibody (HAMA) in radioimmunotherapy, the gene encoding the heavy chain variable region (V H) of the murine monoclonal antibody with high specificity and affinity to carcinoembryonic antigen was fused to the human C γ3 gene to construct the murine human chimeric heavy chain antibody gene, then was linked to core streptavidin which can specifically bind to biotin, facilitating its purification and radioisotope labeling. The fusion gene was expressed in E.coli at high level, accounting for 24% of the total bacteria protein, and was characterized by SDS PAGE and Western blots. When using RIA the content of inclusion bodies was denatured and followed by renaturation, it was shown by using RIA to possess ability to bind to its specific antigen of CEA. Using horseradish peroxidase (HRP) labeled biotin as antibody in Western blots, one band of 70 kD only was detected, demonstrating the fusion protein not only had the ability to bind CEA, but also could bind biotin specifically.

关 键 词：癌胚抗原 嵌合重链 链霉亲和素 基因表达 

分 类 号：R730.3[医药卫生—肿瘤]