It has been recently shown that reversible thermal folding-unfolding, stabilization and high solubility of proteins (e.g. lysozyme) can be achieved when dissolved in protic ionic liquids (e.g. ethylammonium nitrate, EAN).These interesting properties have been so far explored only marginally from the tructural point of view. SANS measurements, complemented by SAXS and DLS ones, can be extremely valuable to explore the nature of the interaction between biomacromolecules and smart new solvents such as ionic liquids.We propsoe to explore the morphology of lysozyme when dissolved in EAN, as a function of concentration and temperature, using the SANS technique and other ancillary measurments.