Effect of nonadditive repulsive intermolecular interactions on the light scattering of concentrated protein-osmolyte mixtures.

The static light scattering of three globular proteins, bovine serum albumin, ovalbumin, and ovomucoid, and binary mixtures of each protein and trimethylamine oxide (TMAO) containing between 10 and 70% protein, were measured as a function of total weight per volume concentration up to 100 g/L. The observed dependence of scattering upon concentration may be accounted for quantitatively by an effective hard sphere model incorporating an extension that takes into account the nonadditive nature of the repulsive intermolecular interaction between protein and TMAO.