iHaptenAb: an integrated hapten-antibody database for rational hapten design and antibody discovery.

Antibodies targeting small molecules play indispensable roles in food safety, environmental monitoring, clinical diagnostics, and immunotherapy. The generation of such antibodies critically depends on hapten design. Although several generic antibody databases exist, an open resource that specifically integrates haptens and the corresponding antibody performance has remained unavailable, thereby limiting data-driven support for rational hapten design and novel antibody discovery. To address this gap, we developed iHaptenAb, which is currently the only publicly accessible comprehensive database dedicated to hapten-antibody relationships. The database contains 589 small-molecule targets, 1678 immunizing haptens, 2090 resultant antibodies, and 6718 immunoassay performance records, totaling 17 129 entries. iHaptenAb systematically compiles hapten structures/properties, conjugation strategies, antibody affinity and specificity parameters, and evaluation metrics for immunoassays. Through multilayer entity relationships, users can trace the full workflow from hapten design to antibody application, enabling the mining of structure-property-performance relationships and supporting machine-learning model training. iHaptenAb is freely accessible at http://ihaptenab.com and http://ihaptenab.cn and is intended to provide a data platform for rational hapten design and the discovery of high-performance antibodies.