We have recently investigated the structure and thermodynamics of Ubiquitin in aqueous IL solutions, focusing on the cooperative solvation of the protein by cations and anions , competitive anion effects , and the role of solvation in protecting or denaturing Ubiquitin in various folding states . We have shown that specific anion-protein interactions play a critical role in solvation, but that the solvation effects are not simply additive when multiple anions are present.