CYP3A4 interactions and metabolic fate of Nile red (NR).

We docked the NR substrate to the CYP3A4 enzyme to identify how the substrate interacts with the heme group in the active site. The two top-scoring poses of NR are show in A, where the NR molecule is shown as sticks in orange (pose 1), and in B, where it is depicted in yellow (pose 2). Heme is shown as magenta sticks, residues F304 and A305 are shown as red spheres, and the rest of the enzyme is shown in green. C: possible reaction steps catalyzed by CYP3A4 in the conversion of NR to product 1 (P1) and product 2 (P2). The product ratio of P1 to P2 will depend on how the NR molecule and intermediate metabolites are positioned in the binding pocket.