Mechanistic insights into protein precipitation by alcohol

► Hen egg-white lysozyme was unfolded in the presence of ethanol. ► The solubility of lysozyme was reduced with increasing ethanol concentration. ► SH-modified lysozyme showed largely unfolded structure in water and ethanol. ► The solubility of SH-modified lysozyme reduced with increasing ethanol concentration. Ethanol prefers hydrophilic interaction rather than hydrophobic interaction.