Structure of CC chemokine receptor 2 with orthosteric and allosteric antagonistsYi Zheng, Ling Qin, Natalia V. Ortiz Zacarías, Henk de Vries, Gye Won Han, Martin Gustavsson, Marta Dabros, Chunxia...Show moreStructure of CC chemokine receptor 2 with orthosteric and allosteric antagonistsYi Zheng, Ling Qin, Natalia V. Ortiz Zacarías, Henk de Vries, Gye Won Han, Martin Gustavsson, Marta Dabros, Chunxia Zhao, Robert J. Cherney, Percy Carter, Dean Stamos, Ruben Abagyan, Vadim Cherezov, Raymond C. Stevens, Adriaan P. IJzerman, Laura H. Heitman, Andrew Tebben, Irina Kufareva & Tracy M. HandelCC chemokine receptor 2 (CCR2) is one of 19 members of the chemokine receptor subfamily of human class A G-protein-coupled receptors. CCR2 is expressed on monocytes, immature dendritic cells, and T-cell subpopulations, and mediates their migration towards endogenous CC chemokine ligands such as CCL2 (ref. 1). CCR2 and its ligands are implicated in numerous inflammatory and neurodegenerative diseases2 including atherosclerosis, multiple sclerosis, asthma, neuropathic pain, and diabetic nephropathy, as well as cancer3. These disease associations have motivated numerous preclinical studies and clinical trials4 (see http://www.clinicaltrials.gov) in search of therapies that target the CCR2–chemokine axis. To aid drug discovery efforts5, here we solve a structure of CCR2 in a ternary complex with an orthosteric (BMS-681 (ref. 6)) and allosteric (CCR2-RA-[R]7) antagonist. BMS-681 inhibits chemokine binding by occupying the orthosteric pocket of the receptor in a previously unseen binding mode. CCR2-RA-[R] binds in a novel, highly druggable pocket that is the most intracellular allosteric site observed in class A G-protein-coupled receptors so far; this site spatially overlaps the G-protein-binding site in homologous receptors. CCR2-RA-[R] inhibits CCR2 non-competitively by blocking activation-associated conformational changes and formation of the G-protein-binding interface. The conformational signature of the conserved microswitch residues observed in double-antagonist-bound CCR2 resembles the most inactive G-protein-coupled receptor structures solved so far. Like other protein–protein interactions, receptor–chemokine complexes are considered challenging therapeutic targets for small molecules, and the present structure suggests diverse pocket epitopes that can be exploited to overcome obstacles in drug design. Show less