Аннотация:
Deep Eutectic Solvents (DESs) are eutectic mixtures composed of
different cations and anions of Lewis and Bronsted acids and bases. With their
favorable properties such as low volatility, biodegradability, low cost, simple
synthesis, etc., they are considered as green media and sustainable replacements
of ionic liquids (1). One amongst many promising applications of DESs is
maintaining the structure of protein in the absence of water. Experimental
studies conducted on different proteins in DESs and their aqueous solutions
have shown that the secondary and most of the tertiary protein structure is
maintained in the DESs and that refolding can also be achieved in aqueous
DESs (2, 3). However, the experiments are limited and the intermolecular
interactions between the solvents and protein are obscured. To this end, we
perform molecular dynamics simulations of lysozyme in its native structure in
the presence of DES composed of urea and choline chloride, known as Reline,
and its aqueous solutions. The simulations are carried to analyze (i) protein
structure at room temperature, (ii) protein structure at high temperatures, when
unfolding occurs and (iii) refolding of thermally unfolded protein structure at
room temperature in reline and its aqueous solutions.