Crystal structure of the adenosine A2A receptor bound to an antagonist reveals a potential allosteric pocket.Sun, B., Bachhawat, P., Chu, M.L., Wood, M., Ceska, T., Sands, Z.A., Mercier, J., Lebon, F., Kobilka, T.S., Kobilka, B.K.
(2017) Proc. Natl. Acad. Sci. U.S.A. 114: 2066-2071
- PubMed: 28167788
- DOI: 10.1073/pnas.1621423114
- PubMed Abstract:
The adenosine A <sub>2A </sub> receptor (A <sub>2A </sub>R) has long been implicated in cardiovascular disorders. As more selective A <sub>2A </sub>R ligands are being identified, its roles in other disorders, such as Parkinson's disease, are startin ...
The adenosine A 2A receptor (A 2A R) has long been implicated in cardiovascular disorders. As more selective A 2A R ligands are being identified, its roles in other disorders, such as Parkinson's disease, are starting to emerge, and A 2A R antagonists are important drug candidates for nondopaminergic anti-Parkinson treatment. Here we report the crystal structure of A 2A receptor bound to compound 1 (Cmpd-1), a novel A 2A R/ N -methyl d-aspartate receptor subtype 2B (NR2B) dual antagonist and potential anti-Parkinson candidate compound, at 3.5 Å resolution. The A 2A receptor with a cytochrome b562-RIL (BRIL) fusion (A 2A R-BRIL) in the intracellular loop 3 (ICL3) was crystallized in detergent micelles using vapor-phase diffusion. Whereas A 2A R-BRIL bound to the antagonist ZM241385 has previously been crystallized in lipidic cubic phase (LCP), structural differences in the Cmpd-1-bound A 2A R-BRIL prevented formation of the lattice observed with the ZM241385-bound receptor. The crystals grew with a type II crystal lattice in contrast to the typical type I packing seen from membrane protein structures crystallized in LCP. Cmpd-1 binds in a position that overlaps with the native ligand adenosine, but its methoxyphenyl group extends to an exosite not previously observed in other A 2A R structures. Structural analysis revealed that Cmpd-1 binding results in the unique conformations of two tyrosine residues, Tyr9 1.35 and Tyr271 7.36 , which are critical for the formation of the exosite. The structure reveals insights into antagonist binding that are not observed in other A 2A R structures, highlighting flexibility in the binding pocket that may facilitate the development of A 2A R-selective compounds for the treatment of Parkinson's disease.
ConfometRx, Inc., Santa Clara, CA 95054; firstname.lastname@example.org.,Discovery Biology, New Medicines, UCB Pharma, B-1420 Braine-l'Alleud, Belgium.,Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA 94305.,Department of Structural Biology, New Medicines, UCB Pharma, Slough SL1 3WE, United Kingdom.,ConfometRx, Inc., Santa Clara, CA 95054.,Discovery Chemistry, New Medicines, UCB Pharma, B-1420 Braine-l'Alleud, Belgium.