Estimation of Affinity of HLA-A*0201 Restricted CTL Epitope Based on the SCORE Function

A set of 70 peptides with affinity for the class I MHC HLA-A*0201 molecule was subjected to quantitative analyses of structure-affinity relationship based on the SCORE function with good results (r2=0.6982, q2=0.6188, RMS=0.280). Then the ‘leave-one-out’ cross-validation (LOO-CV) and an outer test set including 18 outer samples were used to validate the QSAR model, and the results show that the QSAR model has good predictability for outside samples. Statistical analysis showed that the hydrophobic and hydrogen bond interaction played a significant role in peptide-MHC molecule binding. The study also provided useful information for structure modification of CTL epitope, and laid theoretical base for molecular design of therapeutic vaccine.