Effect of sodium salicylate and sodium deoxycholate on fibrillation of bovine serum albumin: comparison of fluorescence, SANS and DLS techniques

The impact of biocompatible additives on the fibrillation and defibrillation of proteins provides valuable insight into the development of suitable formulations for the treatment of protein-related diseases or the storage of proteins in the laboratory. We have studied the effects of the addition of sodium deoxycholate (NaDC) and sodium salicylate (NaSal) on the fibrillation of bovine serum albumin (BSA) using fluorescence, circular dichroism, dynamic light scattering (DLS) and small angle neutron scattering (SANS). Spectroscopic studies indicate that the additives are adsorbed on the surfaces of proteins and change their secondary structures, irrespective of the sequence of addition. DLS and SANS studies show that the addition of either NaSal or NaDC to native proteins slows down or arrests the formation of fibrils. However, the additives do not defibrillate preformed fibrils when added after fibril formation. Thus, NaSal and NaDC can act as potential adjuvants for the prevention of fibril formation in BSA solutions.