Molecular modeling and MD-simulation studies: Fast and reliable tool to study the role of low-redox bacterial laccases in the decolorization of various commercial dyes. (October 2019) - Ahlawat, Shruti
Abstract: Synthetic dyes are toxic and carcinogenic in nature, which also causes environmental pollution. The present study was aimed to decolorize various commercial dyes using purified recombinant bacterial laccases. Laccase gene from Yersinia enterocolitica strain 8081 (y acK ), Y. enterocolitica strain 7 (y acK ) and Bacillus pumilus DSKK1 was cloned in vector pET28a and overproduced in host Escherichia coli BL21. The high yield of recombinant laccase protein resulted in the formation of inclusion bodies, which were further solubilized, refolded, and purified. The purified recombinant laccases were alkali-tolerant and thermostable, with pH optima at 7–8, temperature optima at 60–70 °C and low redox potential. For in silico studies, laccase protein models of B. pumilus DSKK1, Y. enterocolitica strain 7 and Y. enterocolitica strain 8081 were docked with commercial dyes. This is the first and foremost study where the stability of docked complexes of pathogenic and non-pathogenic microorganism has been explored via molecular dynamics (MD) simulations using Gromacs version 4.5.5 with the gromos96 43a force field. Finally, the in silico results were validated experimentally and it was found that purified laccases from B. pumilus DSKK1 and Y. enterocolitica strain 7 efficiently decolorized rose bengal (90.4%), malachite green (77.7%), and congo red (74.5%) dyes. Graphical abstract: Image 1 Highlights: Dye decolorization was performed using alkali tolerant, low redox recombinant laccases. Docking and simulation studies were in harmony with the experimental findings. High dye decolorization up to 90.4% was achieved. Abstract : In silico study suggest bacterial laccases as an efficient dye decolorizing agents. The molecular modeling and MD-simulation study can be used for the rapid screening of the enzymes involved in bioremediation.