IN SILICO STUDY OF BIOREMEDIATION PROPERTY OF MICROBIAL LACCASE ENZYMES 3CG8 AND 1GYC

Abstract

Microbial bioremediation is the process of removing environmental toxins by using microorganisms and/or their products (enzymes or wasted biomass). The current study sought to evaluate the potential of laccase enzymes of microbial origin (bacterial and fungal) as a bioremediating agent for scavenging pollutants such as pharmaceutical, microplastic, and paper mill effluents. Bacterial laccase enzyme with PDB ID 3CG8 and fungal laccase enzyme with PDB ID 1GYC were used; ligand structures were acquired from Pub Chem. UCSF Chimera were used for visualisation and preparation of the protein structures for docking. Achilles docking server was used for blind docking, while AutoDock 4.2.6 was utilised for site-specific docking. The active sites of target proteins were predicted using the Scf bio-online programme for site specific docking. Blind docking with target protein bacterial laccase 3CG8 exhibited prominent binding affinity with Clarithromycin (hydrogen bonding with Thr192 and with Leu78) and with fungal laccase PDB ID 1GYC with Bezafibrate (hydrophobic interactions only). In site specific docking, polycarbonate exhibited the lowest binding energy with both laccase enzyme due to four hydrogen bonding with Ala266, Ile262, His104 and His154 residue of protein 3CG8 and two hydrogen bonding with Ala80, Phe344 of protein 1GYC. The current study demonstrated through an insilico approach laccase enzyme does possess the property of binding with pollutants and might degrade them to fewer toxic by-products. The study also reflected that the binding affinity and stability of binding is more efficient with blind docking in comparison to site specific docking implicating flexibility of the enzyme does affect the binding ability. Further studies might be conducted in terms of in silico prediction of complex degradation products and confirmation of the findings in experimental studies by exposing the pollutants to laccase synthesising microorganisms.