Fig. 8.

PD-incorporated SVM cycle: the prediction-experimental validation-data feedback is a powerful procedure for deorphanization of GPCRs for novel neuropeptides. The original prediction model was constructed by learning positive data (red dots) and negative data (blue dots) for known neuropeptide–GPCR pairs, followed by cell-based signaling assays of each predicted pair; predicted GPCR–peptide pairs are green dots, positive matches are yellow dots, and false positives are purple dots. The feedback of experimentally validated neuropeptide–GPCR pairs updated the prediction model, which enabled the prediction of more positive GPCR–peptide pairs. This improved prediction model indicated that repeated prediction-experimental validation-feedback cycles make the PD-incorporated SVM more “intelligent” and improve the prediction performance.