Physicochemical characterization, structural analysis and homology modeling of bacterial and fungal laccases using in silico methods

摘要

Laccases from various sources like higher plants, fungi as well as bacteria are known to have wide range of applications in various industries such as paper, textile and beverage. This enzyme is extensively studied because of its vital role in bioremediation, biosensors and diagnostics. Phylogenetic analysis of retrieved sequences of laccases from selected bacteria and fungi inferred variation in sequences and these laccases were grouped independently. All laccases of selected organisms are acidic showing computed pI7 and hydrophilic in nature. Presence of disulfide bridges was observed in laccases of bacteria Pseudomonas putida, Haemophilus parasuis HPS11 and Endozoicomonas numazuensis as well as in all selected fungal laccases. N-myristoylation and phosphorylation sites for Protein kinase C and Casein kinase II were found in all selected laccases. Secondary structure prediction revealed dominance of random coils in selected laccases. Validation results of predicted 3D structures of laccase enzymes confirmed that the modeled structures were of good quality. All selected bacterial laccases were intracellular and those of fungal were found to be extracellular. These investigations provide functional information about these laccases and may help to design successful experimental work aiming towards isolation and purification of laccases from closely related organisms. Experimental structures of these laccase enzymes are not yet available, so till then this study will provide a platform for knowing the structural organization responsible for functioning of these enzymes.