Fig. 4.

MD simulations investigating the binding of abiraterone to CYP17A1. (A) PMF profile for the unbinding of abiraterone from CYP17A1. (B) Long, unrestrained MD simulations demonstrated two dominant binding modes of abiraterone in CYP17A1 catalytic site. In pose A, the plane of the steroid moiety is near perpendicular to the plane of the heme. (C) In pose B, abiraterone is parallel to the plane of the heme. The key-binding region of the CYP17A1 active site is shown in magenta. The side chain atoms of important binding residues are shown as sticks, abiraterone as thick sticks, and heme as ball and sticks. C, O, and N atoms are shown in cyan, red, and blue, respectively.