CD28嵌合抗体及与抗原分子的3D空间结构模建

Construction of 3D model of CD28 chimeric antibody with its antigen docked

目的:对1株嵌合抗体(antiCD28:ch-2F5)进行3D建模,并与其抗原分子进行对接,验证是否与抗原抗体结合理论相符,并提供一种抗原抗体及其识别的空间结构分析方法。方法:在http://www.ncbi.nlm.nih.gov网站提交序列进行分析,综合运用GenBank、Protein data bank、GENO-3D等数据库比对分析,用Swiss-model同源建模服务器模建,运用GRAMM-X Protein Docking Web Server在线进行对接,结果采用Chimera软件对嵌合抗体的重、轻链、重/轻链复合体、重/轻链与抗原分子复合体进行3D展示并拍照,并标出抗体重轻链、可变区、恒定区、CDR区、框架区,全方位展示抗体的空间结构。结果:运用该方法构建的重/轻链与抗原分子复合体的3D结构与理论上抗原分子、抗体分子结合的位置相符,对所构建的嵌合抗体从生物信息学角度进行了理论论证。结论:所构建的嵌合抗体分子结构符合抗体的常规结构,与抗原分子结合的位置也符合抗原抗体分子理论结合位点,为抗体的3D结构分析及蛋白质的相互作用提供了例证。

AIM： To construct a 3D model of the chimeric antibodies （ AntiCD28 ： ch-2F5 ） with corresponding antigen molecule docked to theoretically verify the rationality of the binding of antibody with its antigen and to provide a method of 3D identification between antigen and antibody and spatial structure analysis. METHODS： We analyzed the sequence by submitting it to http：//www, ncbi. nlm. nih. gov/ and made a comparison using integratly the 3 databases of Gen-Bank, Protein data bank and GENO-3D. The 3D model was constructed by Swiss-model homology modeling server and molecular docking online was performed by GRAMM-X Protein Docking Web Server. Chimeric heavy chain, light chain, heavy-light chain complex, heavy-light chain and antigen complex were displayed and photographed by the Chimera Software. Meanwhile, the spatial structures of heavy, light chains, variable region, constant region, CDR and frame area were marked by different colours respectively to exhibit the 3D structure on every side. RESULTS： The 3D structure of the heavy-light chain and antigen complex we constructed was consistent well with the theory of antigen binding to antibody molecules. CONCLUSON： The structure of the chimeric antibody we constructed with the bioinformatic method was in accordance with the general structure of antibody, and its antigen binding site was also consistent with the molecular theory. Thus, the model helps to analyze the 3D structure of antibody and antigen-antibody interaction.