氨基酸非键作用指数用于HLA-A*0201限制性CTL表位定量预测研究

Applying three dimensional amino acid index of nonbonding interaction to quantitative prediction of HLA-A*0201-restricted CTL epitope

目的预测SSX-1和SSX-4抗原HLA-A*0201限制性表位。方法从分子的三维空间结构出发,基于静电、立体、疏水这三类与生物活性直接相关的非键作用方式,经主成分分析技术(PCA)得到了一种新的分子结构表达方法——氨基酸非键作用指数。利用该指数结合偏最小二乘(PLS)算法对152个HLA-A*0201限制性CTL表位进行了定量构效关系(QSAR)建模,再使用该模型对SSX-1和SSX-4抗原HLA-A*0201限制性表位进行预测。结果预测出8个活性值大于7的九肽表位。结论通过对SSX-1和SSX-4抗原HLA-A*0201限制性表位的预测,从而为SSX-1和SSX-4抗原HLA-A*0201限制性表位的实验探测和鉴定打下了基础。

Objective To predict the HLA-A ＊ 0201-restricted CrL epitopes in SSX-1 and SSX-4 proteins. Methods A novel three dimension amino acid index of nonbonding interaction （3D-AIN）, which spatially represents molecule structure considering of three kinds of non-bond interaction （electrostatic, sterie and hydrophobie interaction）, was proposed by the principle component analysis （PCA）. Via partial least squares （PLS） algorithm,the quantitative structure activity relationship （QSAR） model was constructed by the 3D-AIN for 152 HLA-A ＊ 0201-restricted CFL epitopes with correlative coefficient R^2cum and cross-validated correlative coefficient Q2 were 0. 505 and 0. 588, respectively, which were better than those of the reference. The model was applied to predict SSX-1 and SSX-4 antigens of HLA-A ＊ 0201- restricted CIL epitopes. Results Eight HLA-A ＊ 0201-restricted CTL epitope candidates were predicted in SSX-1 and SSX-4 proteins. Conclusion The prediction of the CTL epitopes in SSX-1 and SSX-4 proteins will benefit the identification of CTL epitopes by experiment.