Interaction studies of recombinant laccase with co-solutes: Using various spectroscopic, calorimetric, and in silico approaches

Abstract

The co-solute engineering is a rational approach to elucidate protein-molecule interactions which involves an exhaustive understanding of the structural characteristics of active sites of enzymes and their involvement in enzyme function. Laccase has attracted huge interest among scientists due to its potential uses in diverse fields. In this study, we have exploited a co-solute engineering approach to elucidate the protein interactions with polyethylene glycol (PEG of molecular weight of 400 Da, PEG 400) and amino acid (arginine). This study employed a comprehensive range of spectroscopic techniques (absorbance, fluorescence, FTIR, and circular dichroism), calorimetry, and in silico method (molecular docking) to investigate the protein conformations and determine the thermodynamic binding parameters and affinities in the presence or absence of co-solutes. Furthermore, the presence of co-solutes induced notable conformational changes in the secondary structure of the protein, transitioning it from a β -sheet configuration to an α -helical structure. The objective was to gain insights into the effect of co-solutes on the protein behavior and explore the potential of “Protein-co-solute engineering” for identifying target residues that could be modulated to alter the protein's properties. By employing these multidisciplinary approaches, the study aimed to shed light on the interactions between ligands and proteins and their potential for engineering protein function. A comprehensive understanding of the mechanisms governing protein–ligand interactions is vital for progress in drug discovery. By exploring the physical principles that regulate these interactions, such as binding kinetics, thermodynamics, and driving forces, we can uncover fundamental insights into protein folding and stability, offering a solid foundation for the development of innovative therapeutic strategies.