Computational assessment of the structural interaction and binding stability of Enterobacter cloacae aromatic ring-hydroxylating dioxygenase with diphenyl phthalate and PFOS

Abstract

The environmental persistence of phthalates and perfluoroalkyl substances (PFAS) has become a growing concern due to their widespread industrial use, resistance to degradation, and adverse health effects. In this study, we evaluated the in-silico assessment potential of Enterobacter cloacae , focusing on its Aromatic Ring-Hydroxylating Dioxygenase (ARHD) subunit alpha enzyme against Diphenyl Phthalate (DPP) and Perfluorooctane Sulfonate (PFOS). Toxicity profiling using ProTox-III predicted nephrotoxicity and blood-brain barrier permeability for DPP and mutagenicity, ecotoxicity, and neurotoxicity for PFOS. The ARHD protein structure was modeled via AlphaFold, and active sites were identified using PrankWeb. Molecular docking revealed strong binding affinities, with PFOS (-8.0 kcal/mol) and DPP (-7.2 kcal/mol) showing the most favorable interactions. Key amino acid residues such as TYR160, ARG303, and ASN164 were identified as critical for substrate binding. Furthermore, molecular dynamics simulations and MM/GBSA and MM/PBSA analyses confirmed the structural stability and favorable binding energies of the docked complexes. These findings suggest that E. cloacae ARHD may serve as a potent biocatalyst for the binding feasibility of structurally resilient endocrine-disrupting pollutants, providing a foundation for future bioremediation strategies.