Structural-functional analyses of textile dye degrading azoreductase, laccase and peroxidase: a comparative in silico study

Background: Textile industry not only plays a vital role in our daily life but also a prominent factor in improving global economy. One of the environmental concern is it releases huge quantities of toxic dyes in the water leading to severe environmental pollution. Bacterial laccase and azoreductase successfully oxidize complex chemical structure of nitrogen group-containing azo dyes. Additionally, the presence of textile dye infuriates bacterial peroxidase to act as a dye degrading enzyme. Our present study deals with three textile dye degrading enzymes laccase, azoreductase, and peroxidase through analyzing their structural and functional properties using standard computational tools. Result: According to the comparative analysis of physicochemical characteristics, it was clear that laccase was mostly made up of basic amino acids whereas azoreductase and peroxidase both comprised of acidic amino acids. Higher aliphatic index ascertained the thermostability of all these three enzymes. Negative GRAVY value of the enzymes confirmed better water interaction of the enzymes. Instability index depicted that compared to laccase and preoxidase, azoreductase was more stable in nature. It was also observed that the three model proteins had more than 90% of total amino acids in the favored region of Ramachandran plot. Functional analysis revealed laccase as multicopper oxidase type enzyme and azoreductase as FMN dependent enzyme, while peroxidase consisted of α-ß barrel with additional haem group. Conclusion: Present study aims to provide knowledge on industrial dye degrading enzymes, choosing the suitable enzyme for industrial set up and to help in understanding the experimental laboratory requirements as well.

In silico analysis of the structure and interaction of COP1 protein of Arabidopsis thaliana.

Previous studies have shown that COP1 (constitutive photomorphogenic 1) protein of Arabidopsis thaliana plays a crucial role in different aspects of photomorphogenesis. Interaction of COP1 with SPA1 (suppressor of phytochrome A) and other regulatory proteins actively affect light regulatory gene expression in diverse directions. Though several studies have explained the function of COP1 protein, method of its interaction with SPA1 and cryptochromes are still not explained in detail. In this study, in silico analysis was followed to predict the tertiary structure, active site residues, functionally important regions and regular expressions of COP1 protein. Its ease of its interaction with SPA1 and seven other regulatory proteins, namely bZIP transcription factor 56 (HY5), transcription factor HY5-like (HYH), serine/threonine-protein phosphatase 7 (AtPP7), protein long hypocotyl in FAR-RED 1 (HFR1), OBP3-responsive protein 1 (OBP3), transcription factor MYC2 (MYC2/ZBF1) and Z-box binding factor 2 protein (GBF1/ZBF2) was measured using protein-protein docking. Interaction with MYC2 was found to be stronger than with others with a global energy value of -22.46. It was also found that COP1 shared three regions of regular expression with SPA1, the last expression also being present in MYC2/ZBF1 and OBP3. Taken together, the insight into structural and functional properties of COP1 protein presented in this study would be helpful in determining the role of COP1 in unknown mechanisms of photomorphogenesis.