分子模拟在筛选HLA-A2.1高亲和性MART-1 CTL表位中的应用研究

Molecular modeling in selection of MART-1 CTL epitopes stably binding to HLA-A2.1 molecule

目的 探讨计算机分子模拟在CTL表位与HLA A2 1亲和力特性研究中的应用价值。方法 应用SiliconGraphics图像工作站及InsightⅡ软件 ,分别建立MART 16个CTL预测表位与HLA A2 1结合的三维结构 ,并进行分子动力学模拟 ,通过对各结合特征性参数的计算 ,对各表位肽与HLA A2 1结合稳定性进行了比较。应用Merrifield固相多肽合成技术合成上述小肽 ,通过HLA A2 1与各肽亲和力分析试验 ,证实分子模拟结果的可靠性。结果 通过分子模拟手段计算所得 6个表位与HLA A2 1结合特性结果 ,基本与通过实验手段所得结果相符。结论 计算机分子模拟在CTL表位与MHC Ⅰ类分子的亲和力研究中 ,具有简单、直观、快速、准确等优点 ,该方法在筛选MHC Ⅰ类分子高亲和性CTL表位的研究中具有诱人的应用前景。

Objective To verify the practicability of computed molecular modeling in the study of MART 1 CTL epitopes binding to the HLA-A2.1 molecule. Methods Silicon Graphics workstation and InsightⅡ software were used to build 6 CTL epitope candidates of MART 1 and the 3 dimensional structures of them binding to HLA A2.1. Molecular dynamics simulation was carried out to select the best epitope by calculating the parameters related to binding affinity. MHC peptide binding assays was employed to test the binding of HLA A2.1 with 6 nonamer peptides synthesized with Merrifield solid phase polypeptide synthesis according to computer prediction in order to verify the reliability of the results obtained from molecular modeling. Results The results obtained from molecular modeling were consistent with those from the MHC peptide binding affinity assays in substance. Conclusion This study demonstrates that molecular modeling can be used in the study on the affinities of CTL epitope candidates to MHC Ⅰ molecules its convenience, speediness and veracity.