Figure 2. Structure of the A_2AAR−ZM241385 complex and relative ligand binding free energies for mutants.

(A) Starting structure used for the FEP simulations with TM helices shown and colored according to a rainbow representation in anti-clockwise order (TM1 = blue → TM7 = red). Residues subjected alanine mutation are depicted in sticks, together with crystal water molecules mediating receptor-ligand interactions, and dashed lines indicate hydrogen bonds. (B) Calculated (gray bars) and experimental (black bars) relative binding free energies (kcal/mol) for ZM241385 to the fourteen A_2AAR alanine mutants compared to the wt receptor. The star symbol denotes that an experimental value could not be determined and approximates the detection threshold of the experiment.