Conformation changes and diffusion of α-amylase in 1-hexyle-3-methylimidazolium chloride ionic liquid: A molecular dynamics simulation perspective

This study employs extended molecular dynamics simulations to study the effect of 1-hexyl-3-methylimidazolium chloride, i.e. [HMIm][Cl], on structure, conformational stability and transport properties of α-amylase with different water percentages, at 300 and 343 K. The 100 ns simulations imply the positive role of increasing the water content to promote α-amylase conformational stability, in agreement with the reported experimental observations. In fact, a high percentage of water establishes a dynamic barrier to Ionic liquid access to the enzyme and facilitates protein diffusion among the IL molecules to reach its potential substrate. No exact rule can be stated about the effect of temperature and water percentage on the secondary structures of the studied systems, but it is evident that [HMIm][Cl] induces structural changes, in addition to altering the enzyme's water accessible area and catalytic role. According to the overall results, the industrial sectors are encouraged to enhance the water content if they are using [HMIm][Cl] IL in α-amylase containing procedures.