Docking large libraries of molecules against unrefined AlphaFold2 (AF2) models of the σ2 and serotonin 2A (5-HT2A) receptors produced hit rates and affinities as high as those obtained by docking against experimental structures. These results were achieved despite differences in orthosteric residue conformations between the AF2 models and the experimental structures. A cryo–electron microscopy structure of one potent 5-HT2A ligand identified from AF2 docking showed residue accommodations similar to the AF2 prediction. AF2 models may sample low-energy conformations that differ from experimental structures but remain useful for ligand discovery, extending the reach of structure-based drug design.
Classical psychedelics are being studied for treating depression, addiction, anxiety, and cluster headaches. Their therapeutic effects are thought to involve the 5-HT2A serotonin receptor. Seven cryo-EM structures were determined, covering major classes of psychedelic and non-psychedelic agonists, including a β-arrestin-biased compound. These structures reveal both common and distinct molecular interactions between different psychedelics and the receptor. The findings provide a mechanistic understanding of 5-HT2A activation that could aid development of new drugs with fewer side effects.
Random genetic variations in the serotonin 2A receptor can modestly alter how four commonly used psychedelic drugs activate this receptor, with effects that differ depending on the specific drug. Seven naturally occurring receptor variants were tested in the lab; each showed small but statistically significant changes in drug potency and efficacy. These findings suggest that individual genetic differences may influence responses to psychedelic medications.