Effect of Organic Osmolytes on Protein Folding Intermediates

Naturally occurring cellular co-solutes, such as the organic osmolytes, are known to play a crucial role in maintaining the protein functional status and stability, and also possess the ability to modulate protein folding, through their effects on the non-native intermediates that accumulate during the folding processes. Several of these osmolytes have been shown to possess the ability to reshape the folding pathway and the energy landscapes in various proteins. Owing to the plethora of these effects in maintaining protein stability and inducing proper folding, these co-solutes have found their way in molecular biotechnology and are also used in various pharmaceutical formulations. The present chapter highlights the major roles and the effects of osmolytes in modulating the protein folding process. Special focus is given towards their effects on protein folding intermediates and on how they regulate the folding pathways. Their ability to induce proper folding of mutant proteins into functionally active conformations is also discussed.