REU Project 10—Effect of osmolytes on protein stability—Dr. D. Rajalingam, Chemistry Department
Cells are constantly faced with numerous challenges, least among them are drastic variations in wa-ter content and disturbed levels of ions resulting from the osmotic stress. Cells exhibit certain cellular “coping mechanisms” when faced with such osmotic stresses by importing or producing organic com-pounds called osmolytes, which aid in osmotic regulation, such as proline. Other commonly known osmo-lytes are trimethylamine N-oxide, sarcosine, and betaine, and many salts found within cells are considered to be osmolytes as well. The primary function of these compounds is to combat the effects of dehydration in the cell. Primary to this function is the stabilization of proteins, which are particularly susceptible to osmotic stresses but are of key importance to the cell. Osmolytes have been shown to directly impact the stability and solubility of proteins. It has also been shown that organic osmolytes exhibit the function of aiding in protein folding and refolding (as well as regaining biological function) and in preventing aggre-gation. The methods by which osmolytes aid in assuring protein stability is considered as a solvent-oriented process by which protein folding is facilitated by the preferential ordering of solvent molecules. The object of the proposed research is to determine the effect of osmolytes like proline on protein stability and to uncover the mechanism of its function.