Figure 3.
Steroidal (dihydrotestosterone) and nonsteroidal (R-bicalutamide) ligand interactions with the androgen receptor ligand-binding domain binding-pocket. R-bicalutamide (green) W741L complex and dihydrotestosterone (gold) wild-type complex, shown as side views (A and B) and top views (C and D) of the steroidal plane. Ligand and receptor interact mainly through H-bonds (labeled as yellow dotted lines) and hydrophobic interactions. The A-ring and amide bond of the bicalutamide molecule overlaps the steroidal plane of dihydrotestosterone (rings A–D) and shares similar H-bonding pattern, whereas the B-ring (B) folds away from the plane, pointing to the top of the ligand-binding pocket and forming the unique structural feature of this ligand class.