CMG2-Fc融合蛋白突变体筛选及中和炭疽毒素活性分析  

Design and Identify CMG2-Fc Mutants to Neutralizing Anthrax Toxin

作　　者：刘宗伟 任雨春 郗永义[3] 岳俊杰[3] 张连成[3] 邵勇[3] 高丽华[3] 胡显文[3] 周艳荣[3] 吴晓洁[3] 陈红星[3] 

机构地区：[1]常熟市公安局DNA实验室,江苏常熟215500 [2]滕州市工人医院,山东滕州277500 [3]军事医学科学院生物工程研究所,北京100071

出　　处：《现代生物医学进展》2016年第9期1601-1605,共5页Progress in Modern Biomedicine

基　　金：国家自然科学基金项目(81202445)

摘　　要：目的:筛选能有效中和炭疽毒素和抵抗炭疽毒素损伤细胞的CMG2-Fc(炭疽毒素受体II-人免疫球蛋白Fc段融合蛋白)突变体。方法:运用FoldX等计算软件分析CMG2与PA晶体学结构,设计能提高CMG2-PA亲和力的突变体分子,并与人IgG1Fc片段构成融合基因,转染CHO-S细胞并通过亲和层析获得CMG2-Fc突变体蛋白,通过亲和力检测和细胞保护实验分析各突变体中和炭疽毒素能力。结果:筛选并表达了8个CMG2-Fc突变体分子,亲和力实验显示其中E117Q突变可明显提高CMG2-Fc与PA的亲和力(KD=1.35×10-11 mol/L),细胞保护实验提示E117Q突变能有效提高CMG2-Fc中和炭疽毒素能力(CMG2-Fc(E117Q)的IC50为15 ng/μL,而wt CMG2-Fc的IC50为50ng/μL)。结论:CMG2-Fc(E117Q)突变体分子可作为拮抗炭疽毒素损伤的炭疽治疗药物分子,进行进一步研究。Objective： To identify CMG2-Fc mutant to neutralize anthrax toxin. Methods： CMG2-Fc Crystal structure was analysed by Fold X software. CMG2-Fc mutants were designed and transfected in CHO-S cells, those mutants were purified by protein A affinity chromatography. The abilities of CMG2-Fc mutants neutralizing anthrax toxin were analysed by affinity assay and toxin neutralization assay in cells. Results： Eight CMG2-Fc mutants were designed and expressed, the affinity assay results show that E117 Q mutant could strengthen CMG2-PA binding, and cell protection assay results certify that CMG2-Fc（E117Q） mutant has superior ability to neutralize toxin（IC50=15 ng/μL） than wt CMG2-Fc（IC50=50） ng/μL. Conclusion： CMG2-Fc（E117Q） was a superior anti-anthrax toxin molecule and valuable to study more.

关 键 词：炭疽 炭疽毒素 CMG2 FC融合蛋白 

分 类 号：R517.2[医药卫生—内科学] Q75[医药卫生—临床医学]