Crystal structure of the adenosine A2Areceptor bound to an antagonist reveals a potential allosteric pocket.
The adenosine A2Areceptor (A2AR) has long been implicated in cardiovascular disorders. As more selective A2AR ligands are being identified, its roles in other disorders, such as Parkinson's disease, are starting to emerge, and A2AR antagonists are important drug candidates for nondopaminergic anti-Parkinson treatment. Here we report the crystal structure of A2Areceptor bound to compound 1 (Cmpd-1), a novel A2AR/N-methyl d-aspartate receptor subtype 2B (NR2B) dual antagonist and potential anti-Parkinson candidate compound, at 3.5 Å resolution. The A2Areceptor with a cytochrome b562-RIL (BRIL) fusion (A2AR-BRIL) in the intracellular loop 3 (ICL3) was crystallized in detergent micelles using vapor-phase diffusion. Whereas A2AR-BRIL bound to the antagonist ZM241385 has previously been crystallized in lipidic cubic phase (LCP), structural differences in the Cmpd-1-bound A2AR-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 A2AR structures. Structural analysis revealed that Cmpd-1 binding results in the unique conformations of two tyrosine residues, Tyr91.35and Tyr2717.36, which are critical for the formation of the exosite. The structure reveals insights into antagonist binding that are not observed in other A2AR structures, highlighting flexibility in the binding pocket that may facilitate the development of A2AR-selective compounds for the treatment of Parkinson's disease.
ConfometRx, Inc., Santa Clara, CA 95054.
Bingfa
B
Sun
ConfometRx, Inc., Santa Clara, CA 95054.
Priti
P
Bachhawat
ConfometRx, Inc., Santa Clara, CA 95054.
Matthew Ling-Hon
ML
Chu
Discovery Biology, New Medicines, UCB Pharma, B-1420 Braine-l'Alleud, Belgium.
Martyn
M
Wood
Department of Structural Biology, New Medicines, UCB Pharma, Slough SL1 3WE, United Kingdom.
Tom
T
Ceska
Discovery Chemistry, New Medicines, UCB Pharma, B-1420 Braine-l'Alleud, Belgium.
Zara A
ZA
Sands
Discovery Chemistry, New Medicines, UCB Pharma, B-1420 Braine-l'Alleud, Belgium.
Joel
J
Mercier
Discovery Chemistry, New Medicines, UCB Pharma, B-1420 Braine-l'Alleud, Belgium.
Florence
F
Lebon
ConfometRx, Inc., Santa Clara, CA 95054.
Tong Sun
TS
Kobilka
ConfometRx, Inc., Santa Clara, CA 95054; kobilka@stanford.edu.|Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA 94305.
Brian K
BK
Kobilka
D058917:Adenosine A2 Receptor Antagonists / Q000737:chemistry* / Q000378:metabolism / Q000627:therapeutic use; D000495:Allosteric Site; D000818:Animals; D000978:Antiparkinson Agents / Q000737:chemistry / Q000378:metabolism / Q000627:therapeutic use; D018360:Crystallography, X-Ray; D006801:Humans; D008024:Ligands; D010300:Parkinson Disease / Q000188:drug therapy*; D017434:Protein Structure, Tertiary; D043705:Receptor, Adenosine A2A / Q000737:chemistry* / Q000378:metabolism; D016194:Receptors, N-Methyl-D-Aspartate / Q000037:antagonists & inhibitors / Q000378:metabolism; D061987:Sf9 Cells; D018411:Spodoptera; D014227:Triazines / Q000737:chemistry / Q000378:metabolism; D014230:Triazoles / Q000737:chemistry / Q000378:metabolism; D014443:Tyrosine / Q000737:chemistry / Q000378:metabolism
D058917:Adenosine A2 Receptor Antagonists; D000978:Antiparkinson Agents; D008024:Ligands; C121001:NR2B NMDA receptor; D043705:Receptor, Adenosine A2A; D016194:Receptors, N-Methyl-D-Aspartate; D014227:Triazines; D014230:Triazoles; C097270:ZM 241385; D014443:Tyrosine
A2A adenosine receptor; GPCR; Parkinson’s disease; allosteric; structure