Conformational dynamics of poly(acrylic acid)-bovine serum albumin polycomplexes at different pH conditions

Abstract

This work presents the real time surface plasmon resonance (SPR) and fluorescence spectroscopy observation of cooperative interactions between aggregate-forming bovine serum albumin (BSA) and oppositely charged linear macromolecule poly(acrylic) acid (PAA). Interactions between protein and polymer result in formation of polyelectrolyte-protein polycomplexes, which exhibit expressed conformational transformations, especially at low pH. The rate constants of observed kinetic transformations were calculated and found to vary in the range from 0.8 x 10(-3) to 6.7 x 10(-3) for different pH values. The processes of aggregation, sedimentation and conformation of BSA-PAA complex are discussed.