8CU7 image
Entry Detail
PDB ID:
8CU7
Title:
Crystal structure of A2AAR-StaR2-bRIL in complex with a novel A2a antagonist, LJ-4517
Biological Source:
Source Organism:
Host Organism:
PDB Version:
Deposition Date:
2022-05-16
Release Date:
2022-08-31
Method Details:
Experimental Method:
Resolution:
2.05 Å
R-Value Free:
0.21
R-Value Work:
0.17
R-Value Observed:
0.17
Space Group:
C 2 2 21
Macromolecular Entities
Polymer Type:polypeptide(L)
Description:Adenosine receptor A2a,Soluble cytochrome b562
Mutations:S277A
Chain IDs:A
Chain Length:447
Number of Molecules:1
Biological Source:Homo sapiens, Escherichia coli
Primary Citation
GPCR Agonist-to-Antagonist Conversion: Enabling the Design of Nucleoside Functional Switches for the A 2A Adenosine Receptor.
J.Med.Chem. 65 11648 11657 (2022)
PMID: 35977382 DOI: 10.1021/acs.jmedchem.2c00462

Abstact

Modulators of the G protein-coupled A2A adenosine receptor (A2AAR) have been considered promising agents to treat Parkinson's disease, inflammation, cancer, and central nervous system disorders. Herein, we demonstrate that a thiophene modification at the C8 position in the common adenine scaffold converted an A2AAR agonist into an antagonist. We synthesized and characterized a novel A2AAR antagonist, 2 (LJ-4517), with Ki = 18.3 nM. X-ray crystallographic structures of 2 in complex with two thermostabilized A2AAR constructs were solved at 2.05 and 2.80 Å resolutions. In contrast to A2AAR agonists, which simultaneously interact with both Ser2777.42 and His2787.43, 2 only transiently contacts His2787.43, which can be direct or water-mediated. The n-hexynyl group of 2 extends into an A2AAR exosite. Structural analysis revealed that the introduced thiophene modification restricted receptor conformational rearrangements required for subsequent activation. This approach can expand the repertoire of adenosine receptor antagonists that can be designed based on available agonist scaffolds.

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