PPIKB: a data resource of peptide ligand–protein interaction structures and binding affinity records for peptide drug discovery

PPIKB is a curated dataset of experimentally validated peptide–protein interactions, integrating standardized binding affinity measurements (Kd, Ki and IC50 converted to pAffinity) and non-redundant protein–peptide complex structures with residue-level interaction annotations. This version is a frozen snapshot (v1.0) released for reuse and benchmarking; an up-to-date web interface is available at https://ppikb.duanlab.ac/.