Studies to characterize the endogenous expression and pharmacology of peripheral human cannabinoid receptor (hCB2) have been hampered by the dearth of authentic anti-hCB2 antibodies and the lack of radioligands with CB2 selectivity. We recently described a novel CB2 inverse agonist, N-[1(S)-[4-[[4-methoxy-2-[(4methoxyphenyl)sulfonyl] phenyl]sulfonyl] phenyl]ethyl]methane-sulfonamide (Sch225336), that binds hCB2 with high affinity and excellent selectivity versus hCB1. The precursor primary amine of Sch225336 was prepared and reacted directly with [35S]mesyl chloride (synthesized from commercially obtained [35S]methane sulfonic acid) to generate [35S]Sch225336. [35S]Sch225336 has high specific activity (>1400 Ci/mmol) and affinity for hCB2 (65 pM). Using [35S]Sch225336, we assayed hemopoietic cells and cell lines to quantitate the expression and pharmacology of hCB2. Lastly, we used [35S]Sch225336 for detailed autoradiographic analysis of CB2 in lymphoid tissues. Based on these data, we conclude that [35S]Sch225336 represents a unique radioligand for the study of CB2 endogenously expressed in blood cells and tissues.
Home Current Issue Papers in Press Editors' Picks JBC Reviews Characterization of Peripheral Human Cannabinoid Receptor (hCB2) Expression and Pharmacology Using a Novel Radioligand, [35S]Sch225336
Gonsiorek, W., Hesk, D., Chen, S., Kinsley, D., Fine, J. S., Jackson, J. V., Bober, L. A., Deno, G., Bian, H., Fossetta, J., Lunn, C. A., Kozlowski, J. A., Lavey, B., Piwinski, J., Narula, S. K., Lundell, D. J., & Hipkin, R. W. (2006). Home Current Issue Papers in Press Editors' Picks JBC Reviews Characterization of Peripheral Human Cannabinoid Receptor (hCB2) Expression and Pharmacology Using a Novel Radioligand, [35S]Sch225336. Journal of Biological Chemistry, 281(38), 28143-28151. https://doi.org/10.1074/jbc.M602364200