Molecular Insights Into the Role of Arginine on Protein Stabilization

Although arginine is commonly used as an additive to enhance refolding yield and to suppress protein aggregation, the mechanisms through which arginine does so remain largely unexplored. Most of the studies available on arginine-induced stabilization of protein have focused on the thermodynamic aspects, through the preferential interactions of arginine with the proteins, but such an approach, while highly useful, is not necessarily sufficient to shed light on the specific molecular interactions that arginine has with protein residues. The focus of this thesis is to initiate a mechanistic study of arginine?s role in stabilizing proteins. The work presented here involves development of a coarse-grained thermodynamic model to examine the roles of various forces on additive-induced suppression/aggregation of proteins, experimental studies of heat-induced aggregation of selected proteins to examine the effects of arginine, and theoretical and experimental studies on arginine/aromatic-residue interactions to examine the implications of such interactions in protein stabilization.