1. Academic Validation
  2. Crystal Structure of an LSD-Bound Human Serotonin Receptor

Crystal Structure of an LSD-Bound Human Serotonin Receptor

  • Cell. 2017 Jan 26;168(3):377-389.e12. doi: 10.1016/j.cell.2016.12.033.
Daniel Wacker 1 Sheng Wang 2 John D McCorvy 2 Robin M Betz 3 A J Venkatakrishnan 4 Anat Levit 5 Katherine Lansu 2 Zachary L Schools 2 Tao Che 2 David E Nichols 6 Brian K Shoichet 5 Ron O Dror 7 Bryan L Roth 8
Affiliations

Affiliations

  • 1 Department of Pharmacology, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC 27599-7365, USA. Electronic address: dwacker@email.unc.edu.
  • 2 Department of Pharmacology, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC 27599-7365, USA.
  • 3 Department of Computer Science, Stanford University, Stanford, CA 94305, USA; Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA 94305, USA; Institute for Computational and Mathematical Engineering, Stanford University, Stanford, CA 94305, USA; Biophysics Program, Stanford University, Stanford, CA 94305, USA.
  • 4 Department of Computer Science, Stanford University, Stanford, CA 94305, USA; Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA 94305, USA; Institute for Computational and Mathematical Engineering, Stanford University, Stanford, CA 94305, USA.
  • 5 Department of Pharmaceutical Chemistry, University of California, San Francisco, San Francisco, CA 94158-2280, USA.
  • 6 Division of Chemical Biology and Medicinal Chemistry, Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-7360, USA.
  • 7 Department of Computer Science, Stanford University, Stanford, CA 94305, USA; Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA 94305, USA; Institute for Computational and Mathematical Engineering, Stanford University, Stanford, CA 94305, USA; Biophysics Program, Stanford University, Stanford, CA 94305, USA. Electronic address: ron.dror@stanford.edu.
  • 8 Department of Pharmacology, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC 27599-7365, USA; Division of Chemical Biology and Medicinal Chemistry, Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-7360, USA; National Institute of Mental Health Psychoactive Drug Screening Program (NIMH PDSP), School of Medicine, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC 27599-7365, USA. Electronic address: bryan_roth@med.unc.edu.
Abstract

The prototypical hallucinogen LSD acts via serotonin receptors, and here we describe the crystal structure of LSD in complex with the human serotonin receptor 5-HT2B. The complex reveals conformational rearrangements to accommodate LSD, providing a structural explanation for the conformational selectivity of LSD's key diethylamide moiety. LSD dissociates exceptionally slow from both 5-HT2BR and 5-HT2AR-a major target for its psychoactivity. Molecular dynamics (MD) simulations suggest that LSD's slow binding kinetics may be due to a "lid" formed by extracellular loop 2 (EL2) at the entrance to the binding pocket. A mutation predicted to increase the mobility of this lid greatly accelerates LSD's binding kinetics and selectively dampens LSD-mediated β-arrestin2 recruitment. This study thus reveals an unexpected binding mode of LSD; illuminates key features of its kinetics, stereochemistry, and signaling; and provides a molecular explanation for LSD's actions at human serotonin receptors. PAPERCLIP.

Keywords

GPCR; crystallography; hallucinogens; serotonin receptor; structure-function.

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