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.