Ionic liquids

which have unique

modulated molecular structure and excellent physicochemical properties

are applied to study the structural stability of protein. In the present study

insulin was selected as a heat sensitive protein medicine in order to investigate the bioactive structural stability of protein in ionic liquids with different mass fractions of water by using molecular dynamics simulation and microcalorimetry. In order to analyze thoroughly the relationship between the content of water molecules and the protein stability

the interaction energy between the ionic liquids and the insulin was calculated. Finally

the experimental results show that the thermal denaturation temperature of insulin is more than 68℃ when the mass fraction of water is less than 25.00%. Moreover

in the hydrated ionic liquids at the water content as 25.00%

a large number of cations and anions are adsorbed on the surface of insulin owing on the strong electrostatic interaction between the insulin and the ions

which reveals the stabilizing effect of hydrated ionic liquids. Generally

macroscopic experimental study and microscopic dynamics calculation

as attempted by this research

provide a new analytical method to interpret the stabilization mechanism of ionic liquids with different water content for protein.