Mapping the allosteric sites of the A2A adenosine receptor

The A2A adenosine receptor (A2AAR) is a G protein‐coupled receptor that is pharmacologically targeted for the treatment of inflammation, sepsis, cancer, neurodegeneration, and Parkinson's disease. Recently, we applied long‐timescale molecular dynamics simulations on two ligand‐free receptor conformations, starting from the agonist‐bound (PDB ID: 3QAK) and antagonist‐bound (PDB ID: 3EML) X‐ray structures. This analysis revealed four distinct conformers of the A2AAR: the active, intermediate 1, intermediate 2, and inactive. In this study, we apply the fragment‐based mapping algorithm, FTMap, on these receptor conformations to uncover five non‐orthosteric sites on the A2AAR. Two sites that are identified in the active conformation are located in the intracellular region of the transmembrane helices (TM) 3/TM4 and the G protein‐binding site in the intracellular region between TM2/TM3/TM6/TM7. Three sites are identified in the intermediate 1 and intermediate 2 conformations, annexing a site in the lipid interface of TM5/TM6. Five sites are identified in the inactive conformation, comprising a site in the intracellular region of TM1/TM7 and in the extracellular region of TM3/TM4 of the A2AAR. We postulate that these sites on the A2AAR be screened for allosteric modulators for the treatment of inflammatory and neurological diseases. We uncover five non‐orthosteric sites on the A2A adenosine receptor that can be screened for allosteric modulators for the treatment of inflammatory and neurological diseases. Site 1 is in the intracellular region of the transmembrane helices (TM) 3/TM4, and site 2 is the G protein‐binding site between TM2/TM3/TM6/TM7. Site 3 is on the lipid interface of TM5/TM6, site 4 is in the intracellular region of TM1/TM7, and site 5 is in the extracellular region of TM3/TM4.