Nature, Vol. 574, pp. 468–471, 27 July 2017, DOI: 10.1038/nature23272
Crystal structures of agonist-bound human cannabinoid receptor CB1
Tian Hua, Kiran Vemuri, Spyros P. Nikas, Robert B. Laprairie, Yiran Wu, Lu Qu, Mengchen Pu, Anisha Korde, Shan Jiang, Jo-Hao Ho, Gye Won Han, Kang Ding, Xuanxuan Li, Haiguang Liu, Michael A. Hanson, Suwen Zhao, Laura M. Bohn, Alexandros Makriyannis, Raymond C. Stevens & Zhi-Jie Liu
Abstract
The cannabinoid receptor 1 (CB1) is the principal target of the psychoactive constituent of marijuana, the partial agonist Δ9-tetrahydrocannabinol (Δ9-THC)1. Here we report two agonist-bound crystal structures of human CB1 in complex with a tetrahydrocannabinol (AM11542) and a hexahydrocannabinol (AM841) at 2.80 angstrom and 2.95 angstrom resolution, respectively. The two CB1–agonist complexes reveal important conformational changes in the overall structure, relative to the antagonist-bound state2, 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 numbering3) 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.
文章链接：http://www.nature.com/articles/nature23272
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