Figure 6.

Docking model of the interaction between human adenosine A_2B receptor and nifedipine. Nifedipine is shown as a stick model, with carbon coloured in yellow, nitrogen in blue, hydrogen in white, and oxygen in red. Broken lines connecting Tyr10^1.35, Ala64^2.61, His280^7.42, and Ser279^7.42 represent possible hydrogen bonds (or CH…O interactions) with nifedipine. The distances of nifedipine from Tyr10^1.35, Ala64^2.61, Phe173^ECL2.52, His280^7.42, and Ser279^7.42 were calculated to be 3.38 Å, 3.42 Å, 3.35 Å, 2.86 Å, and 3.54 Å, respectively, without taking account of hydrogens. The dihydropyridine of nifedipine can form a π–π stacking interaction with Phe173^ECL2.52.