Crystal structures of agonist-bound human cannabinoid receptor CB 1

Nature. 2017 Jul 27;547(7664):468-471. doi: 10.1038/nature23272. Epub 2017 Jul 5.

Abstract

The cannabinoid receptor 1 (CB1) is the principal target of the psychoactive constituent of marijuana, the partial agonist Δ9-tetrahydrocannabinol (Δ9-THC). Here we report two agonist-bound crystal structures of human CB1 in complex with a tetrahydrocannabinol (AM11542) and a hexahydrocannabinol (AM841) at 2.80 Å and 2.95 Å resolution, respectively. The two CB1-agonist complexes reveal important conformational changes in the overall structure, relative to the antagonist-bound state, including a 53% reduction in the volume of the ligand-binding pocket and an increase in the surface area of the G-protein-binding region. In addition, a 'twin toggle switch' of Phe2003.36 and Trp3566.48 (superscripts denote Ballesteros-Weinstein numbering) is experimentally observed and appears to be essential for receptor activation. The structures reveal important insights into the activation mechanism of CB1 and provide a molecular basis for predicting the binding modes of Δ9-THC, and endogenous and synthetic cannabinoids. The plasticity of the binding pocket of CB1 seems to be a common feature among certain class A G-protein-coupled receptors. These findings should inspire the design of chemically diverse ligands with distinct pharmacological properties.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Binding Sites
  • Cannabinoid Receptor Agonists / chemical synthesis
  • Cannabinoid Receptor Agonists / chemistry*
  • Cannabinoid Receptor Agonists / pharmacology
  • Crystallography, X-Ray
  • Dronabinol / analogs & derivatives*
  • Dronabinol / chemical synthesis
  • Dronabinol / chemistry
  • Dronabinol / pharmacology
  • Droperidol / analogs & derivatives*
  • Droperidol / chemical synthesis
  • Droperidol / chemistry
  • Droperidol / pharmacology
  • Heterotrimeric GTP-Binding Proteins / metabolism
  • Humans
  • Ligands
  • Molecular Docking Simulation
  • Protein Binding
  • Protein Conformation
  • Receptor, Cannabinoid, CB1 / agonists*
  • Receptor, Cannabinoid, CB1 / antagonists & inhibitors
  • Receptor, Cannabinoid, CB1 / chemistry*
  • Receptor, Cannabinoid, CB1 / metabolism

Substances

  • 7'-Isothiocyanato-11-hydroxy-1',1'-dimethylheptylhexahydrocannabinol
  • AM11542
  • Cannabinoid Receptor Agonists
  • Ligands
  • Receptor, Cannabinoid, CB1
  • Dronabinol
  • Heterotrimeric GTP-Binding Proteins
  • Droperidol