Binding interaction of laccases and Peroxidases from Bacillus Subtilis after Industrial dyes exposure: Molecular docking and Molecular dynamics simulation studies

Abstract

Wastewater treatment in textile and dye industry mainly involves treatment of highly colored water containing variety of dyes in different concentrations. The wastewater needs to be treated prior to discharge by effectively removing dye color in order to protect environment and as per the statutory guidelines. Laccases and peroxidase are key enzymes that help microbes to degrade dyes as well as their intermediatee metabolites. Various dyes have been reported to be degraded by bacteria, but it is still unclear how these enzymes function during dye degradation, for complete removal of these toxic dyes from the system, it is essential to understand the molecular function of enzymes. The interaction of laccase and peroxidase with different toxic dyes was investigated using molecular docking. Based on the highest binding energy five dyes were screened showing high binding interaction with laccase and peroxidase. Molecular docking results indicate that out of the five dyes two were found to be more stable as a target for degradation through Bacillus subtilis laccase and peroxidase, which is yellow 2g and reactive blue respectively. As a result, subsequent research focused solely on the results of two substrates: yellow 2g and reactive blue. Analysis of Molecular Dynamics simulation revealed that yellow 2g and reactive blue form hydrogen and hydrophobic bond with the active site of laccase and peroxidase to keep it stable in aqueous solution. The conformation of laccase and peroxidase is greatly altered by the inclusion of all two substrates in the active site. The Molecular Dynamics simulation findings show that laccase and peroxidase complexes remain stable throughout the catalytic reaction. Therefore, this research provides a molecular understanding of laccase and peroxidase expression and its role in the bioremediation of the yellow 2g and reactive blue.