Modelagem molecular da biodegradação do corante vermelho congo por lacases

Abstract

The worldwide increase in urbanization and industrial activities has ledtotheproduction and introduction of contaminating molecules into ecosystems. Pollutionofwater bodies by untreated sewage causes numerous damages to specieslivinginthe aquatic environment. Biotechnological processes and physical, chemical, andbiological strategies have been developed to remove these contaminantsfromanthropogenically polluted waters. From the perspective of bioremediation, lacasesare enzymes capable of degrading phenolic, aromatic, and non-aromatic compounds,including synthetic dyes from the textile industry. In this context, the present workproposes to analyze the intermolecular contacts of Congo red dye coupledtolacasesfrom Tratametes versicolor (CR -LacTv) and Pycnoporus sanguineus (CR-LacPs)qualitatively (type of chemical bonding), quantitatively (interaction energy), andcomparatively, including the identification of interaction patterns. To describetheindividual ligand-receptor type binding energies present in these biocomplexes, weused the molecular fractionation scheme with conjugated caps (MFCC) intheframework of density functional theory (DFT). The results indicate a higher affinityofthe Congo red dye for the lacase of Pycnoporus sanguineus. In this case, thedyeinteracts with LacPs (LacTv) with a binding energy of -38.26 kcal/mol (-19.26kcal/mol), with 63.3% (63.6%) of the intermolecular contacts occurring withtheaminoacids of the receptor from the iii (i) region of this ligand. The major residuesof theCR-LacPs (CR -LacTv) complex are ARG161, PHE162, GLY392, GNL160, SER393,PRO391, PHE265, and GLY266 (PHE162, ALA161, GLY266, ALA393, PHE265,PRO391, PRO160, GLY392), in which we highlight the existence of six (five) largehydrogen bonds and two (three) hydrophobic contacts in CR -LACPs (LacTv). Thestructural and energetic description of the interactions of the biocomplexesinquestion helps to understand the differences in terms of stability andefficacyofenzymes of the same family but different organisms. Consequently, it will allowstudies to increase the effectiveness of bioremediation promoted by suchenzymesfollowing targeted point changes.