Diffusion of Anisotropic Proteins with Patchy Interactions – Insight From Combining Scattering, Rheology and Computer Simulations

The static and dynamic properties of concentrated protein solutions are essential ingredients for our understanding of the cellular machinery or formulating biopharmaceuticals. This is particularly demanding as many proteins have anisotropic shapes and patchy interactions. We show how we can use a combination of advanced characterization techniques such as light and x-ray scattering, neutron spin echo measurements and microrheology experiments, combined with the theoretical toolbox from colloid physics and state-of-the-art computer simulations, to assess and predict protein diffusion in concentrated solutions. We will in particular address the influence of shape anisotropy and weak attractive patches on the structural and dynamic properties of concentrated protein solutions, and discuss how we can combine interparticle interaction effects and the formation of (transient) equilibrium aggregates in an attempt to understand and predict properties such as the concentration dependence of the osmotic compressibility, the diffusion coefficient, and the zero shear viscosity of dense protein solutions.