Effects of salts, buffers and sucrose on protein–protein attractive and repulsive interactions
Year: 2025
Type: article
Abstract: • The choice of buffer had a major impact on repulsion between proteins in solution. • Buffers can be ranked Histidine: Acetate: Phosphate: Citrate. • Sodium chloride reduced repulsion between proteins by charge screening. • Halide anions’ effect on repulsion followed the inverse Hofmeister series. • Sucrose also reduced repulsion between proteins. Repulsion between proteins is an advantageous attribute in aqueous protein formulations as it enhances solubility, and reduces precipitation, opalescence and viscosity. The interaction parameter ( k D ) of lysozyme in solution was measured using dynamic light scattering (DLS). k D is a measure of attraction and repulsion between particles. All anions tested caused a drop in the k D of lysozyme consistent with charge screening. The buffer, citrate caused the greatest negative impact on the k D value of lysozyme, possibly due to a combination of charge screening, charge reversal and non-covalent crosslinking of the lysozyme molecules. Conversely, histidine buffer, had the least impact on the k D value of lysozyme. The ionic and non-ionic tonicity modifiers, sodium chloride and sucrose, both reduced repulsion between lysozyme molecules in both citrate and histidine buffers.
Authors: Jaslene A. Francis, Leah Wright, Richard van Wegen, Chun-Xia Zhao, Robert J. Falconer
Institution: The University of Adelaide
Language: English
Subfield: Physical and Theoretical Chemistry
Field: Chemistry
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $4,650
OpenAlex ID: W4407165151