Rational Design and Computational Analysis of Covalent Benzofuran Fluorophosphonate Inhibitors in a Heme-Depleted Model of CYP1A1

Abstract

The cytochrome P450 isoform, CYP1A1, occupies a paradoxical role in cancer biology, functioning both as a metabolic gatekeeper of xenobiotics and as a catalyst in the bioactivation of procarcinogens. While conventional inhibitor design has largely targeted the catalytically-active, heme-bound ( holo- ) form of CYP1A1, comparatively little attention has been paid to its dynamic equilibrium with its heme-free states (heme-depleted holo - and apo- ) under conditions of oxidative stress and altered heme homeostasis: hallmarks of the neoplastic microenvironment. In this study, we explore the hypothesis that transient heme depletion (ligand exchange) may expose a therapeutically exploitable window for covalent inhibition. To this end, a series of six benzofuran fluorophosphonate derivatives (BMFP-C1 - C6) were rationally designed as hypothetical electrophilic inhibitors capable of engaging nucleophilic residues within the active site of heme-depleted CYP1A1. A multi-tiered computational workflow was employed, comprising molecular docking (AutoDock Vina), pseudo-covalent docking (rDock), molecular dynamics (GROMACS), binding affinity prediction (K DEEP ), geometric analysis of nucleophilic attack (distance and angles), and normal mode analysis (NMA). Across these analyses, ligand BMFP-C1 consistently exhibited a favorable convergence of properties, including strong predicted binding affinity, rapid attainment of ligand-protein equilibrium, and a geometrically-permissive orientation for nucleophilic substitution at phosphorus. Notably, structural inspection of the BMFP-C1-CYP1A1 complex revealed the proximal arrangement of Asp320, Lys499, and Thr497, suggestive of a pseudo-“catalytic triad” capable of facilitating a two-step nucleophilic substitution (S N 2 P ) mechanism. While this mechanistic proposal remains speculative, the alignment of geometric and energetic indicators supports the plausibility of covalent engagement mediated by transient, heme-depleted holo -CYP1A1 accessibility. Taken together, these findings suggest that targeting the heme-depleted, pre- apo conformational landscape of CYP1A1 may represent a viable, albeit underexplored, strategy for hypothetical covalent inhibitor design. The present work thus serves as a computationally-grounded, hypothesis-generating framework for the future synthesis and biochemical evaluation of fluorophosphonate-based CYP1A1 inhibitors.