BIOPHYSICS SEMINAR Featuring Klaus Gawrisch, National Institutes of Health “Biophysical characterization of recombinant type II cannabinoid receptor, CB2”

“Biophysical characterization of recombinant type II cannabinoid receptor, CB₂”

Tomohiro Kimura¹, Krishna Vukoti¹, Diane L. Lynch², Dow P. Hurst², Patricia H. Reggio², Alexei A. Yeliseev¹, Klaus Gawrisch¹

¹Laboratory of Membrane Biochemistry and Biophysics, NIAAA, NIH, Bethesda, MD 20892

²Department of Chemistry and Biochemistry, University of North Carolina, Greensboro, NC 27402

The human CB₂ receptor belongs to the class of rhodopsin-like G protein-coupled membrane receptors (GPCR). It is primarily located in cells of immune and hematopoietic systems such as thymus, spleen, and tonsil.  The CB₂ receptor plays a major role in inflammatory processes which has raised considerable pharmacological interest. The need for novel treatments of inflammation and pain has encouraged development of specific ligands for CB₂ that are free from the psychoactive side effects of conventional phytocannabinoids. Our laboratory expresses CB₂ in E-coli in the milligram range for subsequent purification and reconstitution into proteoliposomes of controlled composition. The reconstituted receptor is fully functional as established by ligand binding and activation of cognate G protein. In difference to studies on crystalline GPCR, we conduct experiments on wild type receptor imbedded into its natural environment, the lipid matrix. Our main research tool is solid-state nuclear magnetic resonance (NMR).  For deeper interpretation of results, we collaborate with the Reggio laboratory on molecular dynamics simulations of CB₂. Data on lipid-protein interaction, binding of endogenous and synthetic ligands to CB₂, as well as a progress report on NMR studies of CB₂ to follow ligand-induced structural changes will be presented.