Cytochrome P450 2W1: Identification of new inhibitors, active site ligands, and pharmacophores

Cytochrome P450 2W1 is an orphan P450 enzyme with little known about its endogenous ligands or function. It is expressed early in fetal colon but typically silenced in healthy adult tissues. Its reactivation in colorectal cancer has been explored to tissue specifically activate certain duocarmycin prodrugs. However, CYP1A1 in healthy tissues can also activate these prodrugs, exposing them to duocarmycins' ultrapotent cytotoxicity. Therefore, this study aims to identify structural features of the CYP2W1 active site that may be exploited to design a duocarmycin prodrug more selectively activated by CYP2W1. Thus, the CYP2W1 ligand profile was investigated using multiple screens. In total, 694 inhibitors of CYP2W1-mediated metabolism were identified. Azoles are frequently nonspecific P450 inhibitors because they coordinate the catalytic heme iron. Screening a focused library of such compounds identified 67 binding CYP2W1. Most of these compounds could be used to generate a CYP2W1 pharmacophore, revealing one hydrophobic and two aromatic ring features consistent among these compounds. Furthermore, the placement of a hydrogen bond acceptor on either side of the azole ring differentiated those binding with high and low affinity. These physiochemical features and their relative arrangement within the CYP2W1 active site may inform the development of more selective duocarmycin prodrugs.