Design, synthesis and structural mechanism of action of TRPV1 agonist MSP20 with long-lasting analgesic effect

Transient receptor potential vanilloid type-1 (TRPV1) channel is a polymodal receptor involved in pain perception and neuronal signalling that represents a promising target for the development of analgesics and neuroprotective agents. In this study we implement a combination of computational techniques and targeted design of chemical libraries to discover benzothiophene-substituted TRPV1 agonists with high affinity and efficacy toward TRPV1. In vitro functional experiments show that prolonged or repeated exposure to these compounds induce calcium-dependent desensitization of TRPV1, making it insensitive to noxious stimuli. We solve a cryo-electron microscopy (cryo-EM) structure of human TRPV1 (hTRPV1) in complex with the most promising benzothiophene-substituted agonist MSP20. The structure reveals molecular details of MSP20 binding to the vanilloid site and a desensitized conformation of hTRPV1, characterized by the closed ion channel pore, α-helical C-terminus and distinct behaviour of annular lipids. Our in vivo experiments demonstrate that MSP20 exhibits robust and long-lasting antinociceptive activity with ex-vivo neuroprotective effects, supporting the perspective of benzothiophene-substituted vanilloids as future analgesics.