The endocannabinoid system modulates physiological processes including appetite, pain-sensation, mood, and memory. Endogenous cannabinoids such as anandamide exert their influence by binding to cannabinoid receptors, proteins which are expressed on the cell membrane and are members of the G-protein coupled receptor family. Cannabis is a plant made up of over 500 different compounds, including the phytocannabinoids tetrahydrocannabinol (THC) and cannabidiol (CBD), as well as numerous terpenes, flavonoids, and fatty acids. It is known that THC, CBD and synthetic cannabinoids with analogous structures can bind to cannabinoid receptors, displacing endocannabinoids due to their higher binding affinity (smaller dissociation constant, Kd). Researchers also suspect that non-cannabinoid components of the plant (i.e., the terpenes) may modulate binding to the cannabinoid receptors.
In previous work in our lab, we investigated the binding of low molecular weight thiols (odorants such as tert butyl mercaptan) deployed to promote fuel gas safety (J.L. Burger, K.M. Jeerage, and T.J. Bruno Analytical Biochemistry (2016)) and the crucial role of metals in regulating the response of odorant receptors (Li et al. Journal of the American Chemical Society (2016)). This related project (Activation and Deactivation of Transmembrane G-Protein Coupled Receptors in Olfaction) utilized Hana3a cells, which had to be transfected to express the odorant receptor under investigation. This binding was investigated by use of saturation transfer difference (STD) nuclear magnetic resonance (NMR) spectroscopy. STD-NMR spectroscopy is a method for detecting the interactions of small ligands with large proteins. Cultures with poor transfection efficiency do not generate enough signal for STD-NMR spectroscopy and this has hindered method development.
We seek proposals aimed at determining the dissociation constants (Kd) of endocannabinoids, phytocannabinoids, and synthetic cannabinoids for two known receptors within the endocannabinoid system: Cannabinoid Receptor 1 (CB1) found primarily in the nervous system and Cannabinoid Receptor 2 (CB2) found primarily in the immune system. Proposals that investigate the impact of terpenes on the dissociation constants or the behavior of drug mixtures are of interest. These measurements will aid forensic investigators and law enforcement develop an accurate device to detect persons under the influence of drugs. We are also interested in proposals that improve the underlying STD-NMR measurement for live cells. A 600 MHz NMR, cell culture facility, and other analytical techniques will be available to develop this project.
Cannabis; Cannabinoid; Cells; Drugs; Forensics; HeLa cells; Nuclear magnetic resonance spectroscopy; Receptors; Terpenes