Chemically diverse antagonists inhibit human TRPV1 through ligand-specific interaction networks

Abstract

Transient receptor potential vanilloid 1 (TRPV1) mediates thermosensation and pain and is a target for non-addictive analgesics; however, clinical candidates have failed due to thermoregulatory and thermosensory side effects. Limited structural data for human TRPV1 (hTRPV1) bound to clinically relevant antagonists has constrained mechanistic insight. Using chemoinformatics-informed cryo-EM and BRET assays, we identify variable antagonist target engagement across diverse chemotypes, including failed clinical compounds. A structure of hTRPV1 bound to 6-iodo-dihydrocapsaicin shows how a single atom substitution converts an agonist into an antagonist. Additional structures with Asivatrep, Mavatrep, and JNJ-17203212 reveal vanilloid pocket plasticity and divergent interaction networks, including lipid co-binding. Mutagenesis of ligand-interacting residues further demonstrates distinct contributions to antagonist engagement. Despite this diversity, antagonists converge on a conserved inhibited state, showing high potency is maintained across flexible binding modes. These findings refine our understanding of hTRPV1 antagonism and inform strategies for next-generation analgesics with improved safety.