MOLECULAR DOCKING STUDIES ON THE POTENTIAL OF LACCASE ENZYME FOR BIODEGRADATION OF ANTIBIOTIC CONTAMINANTS

Abstract

The pervasive presence of antibiotic pollutants in aquatic and terrestrial ecosystems poses a significant threat to environmental and public health, primarily due to the promotion of antimicrobial resistance (AMR). Conventional treatment technologies are often insufficient to degrade these persistent pharmaceutical contaminants. This study explores the potential of the laccase enzyme, a multi-copper oxidase known for its broad substrate specificity, in the bioremediation of selected antibiotic pollutants through in silico molecular docking techniques. Eight commonly detected antibiotics—Azithromycin, Erythromycin, Ciprofloxacin, Amoxicillin, Norfloxacin, Penicillin, Tetracycline, and Oxytetracycline—were docked against the laccase enzyme (PDB ID: 1GSK) using PyRx software. Ligand structures were sourced from PubChem and processed via Avogadro. Binding affinities and molecular interactions were analyzed using BIOVIA Discovery Studio and PLIP to identify key interacting amino acid residues and interaction types, including hydrogen bonding, hydrophobic interactions, π–π stacking, and salt bridges. Ciprofloxacin and Tetracycline exhibited the highest binding affinities (-7.5 and -7.7 kcal/mol respectively), suggesting strong and specific interactions with the active site of laccase. Detailed interaction profiling revealed conserved polar and aromatic residues critical to binding stability and specificity. The results underscore laccase’s potential as a promising biocatalyst for enzymatic degradation of antibiotics, offering an environmentally friendly alternative to conventional remediation methods. Future work should focus on experimental validation, enzyme engineering for enhanced specificity, and integration into scalable bioreactor systems for practical wastewater treatment applications