Understanding the role of lignin peroxidase (LiP) from Phanerochaete chrysosporium for refinery wastewater remediation: Insights from molecular docking and simulation.

This study investigates the molecular interaction of lignin peroxidase (LiP) enzyme produced by Phanerochaete chrysosporium fungi in treating petroleum refinery wastewater (RWW) through a computational approach. RWW contains various aromatic hydrocarbons and recalcitrant organic compounds, which harm the ecosystem. While previous work focused on the activity of LiP and manganese peroxidase (MnP) protein, and established MnP interaction with pollutants, the molecular interaction of LiP remained unexplored. This study extends the work by performing molecular docking and simulation of LiP with the same RWW pollutants. Docking revealed strong binding affinities of LiP, particularly with Cholesterylacetate (-10.27 kcal/mol), mediated by hydrophobic residues (Phe46, His47, His176) in the active site. However, molecular dynamics simulation revealed significant conformational flexibility with high residue fluctuations (RMSF >1.2 nm) at key active sites (Ile42/Phe46) and increased global dynamics (Rg up to 1.9). This suggests that although LiP can establish a strong interaction initially, its structure becomes less stable over prolonged exposure compared to MnP. The differences imply potential synergy in a multi-enzyme system, where LiP enables initial binding of hydrophobic non-phenolics, while MnP facilitates the degradation of polar phenolic intermediates. This study validates P. chrysosporium as a promising fungal species for treating diverse industrial effluents.