Protein refolding in predominantly organic media markedly enhanced by common salts.

The refolding/reoxidation of unfolded/reduced hen egg-white lysozyme was investigated in a variety of predominantly nonaqueous media consisting of protein-dissolving organic solvents and water. It was discovered that LiCl and other common salts dramatically (up to more than 100-fold) increased the refolding yield of lysozyme in such nonaqueous systems, while reducing it in water. The mechanism of this surprising phenomenon appears to involve salt-induced suppression of nonspecific lysozyme aggregation during refolding due to an enhanced protein solubility.