Molecular interaction of ethylene glycol to hurt Myoglobin: Insights from spectroscopic and molecular modeling studies

Abstract

Myoglobin protein as a polypeptide chain with known sequence plays major role in facilitation of transfer, propagation and storage of oxygen in muscular tissue. Organic Osmolytes such as ethylene glycol are among the substances hindering the opening of proteins and besides, they maintain effective folding and protein performance in an improper ambient condition. For this purpose, in the present study the effect of the interaction of ethylene glycol organic solvent with myoglobin protein soluble in 50 mM Sodium Phosphate Buffer was investigated. The ethylene glycol effect on the myoglobin thermal stability was assessed and it was observed that the myoglobin thermal stability in the presence of ethylene glycol would increase. Also considering the effect of ethylene glycol on the myoglobin structure, the increase in UV–Vis adsorption and decrease of intrinsic fluorescence emission intensity in the protein spectra was observed. Quenching is performed statically and the binding between ethylene glycol and myoglobin is done autonomously, while the major complex formation forces between protein and ligand are of an der Waals interaction and hydrogen bonds. The theoretical results obtained from molecular docking technique shows that the binding energy is negative, and the electrostatic energies have minor contribution in the formation of binding as compared to hydrogen and Van der Waals bounds. Also, the results obtained from molecular simulation confirmed the stabilization of myoglobin protein due to the formation of the complex with ethylene glycol and were in full agreement with the experimental results.