Does poly (ionic liquid) modulates the non-covalent interactions of hen egg white lysozyme: Elucidation of biomolecular Interactions between biomolecule and macromolecule solvent
Abstract Recent emergence of poly (ionic liquid) (PIL) has generated a lot of interest in material chemistry field with their wide range of applications. However, use of poly(ionic liquids) as co-solvents for protein stability are still unknown. Therefore, herein this work, we report the synthesis and characterization of a vinylbenzyl chloride and N-methylimidazole-based poly (ionic liquid) to study the biomolecular interactions with an antimicrobial enzyme lysozyme. After using different spectroscopical, thermal and morphological studies, it is concluded that PIL at lower concentrations (0.005-0.2 mg/mL) do not affect the structural, thermal (only 0.005 mg/mL) stability of lysozyme. However functional stability determined by enzymatic activity of the lysozyme gets decreased with increased in concentrations of PIL. Furthermore, higher Tm values do not necessarily indicate higher thermal stability of protein however, a combination of complete set of thermodynamic parameters such as Tm, δCp and δuS (at Tm), and δuG, is more helpful in predicting the protein stability. Morphological changes observed using TEM also showed interaction of PIL with lysozyme at lower concentrations whereas protein has denatured at higher concentration of PIL. As mentioned before, it is first kind of study using PIL as co-solvent for lysozyme stability studies which pave way for future similar studies using different classes of PIL for stability evaluation of protein.