Dresden 2011 – wissenschaftliches Programm
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CPP: Fachverband Chemische Physik und Polymerphysik
CPP 38: Poster: Colloids and Complex Liquids
CPP 38.2: Poster
Mittwoch, 16. März 2011, 17:00–19:00, P2
Static and Dynamic Crowding Effects from Charge- to Sterically Stabilized Protein Solutions — •Fabio Zanini1,3, Marco Heinen2, Felix Roosen-Runge1, Fajun Zhang1, Marcus Hennig1,3, Tilo Seydel3, Gerhard Nägele2, and Frank Schreiber1 — 1Institut für Angewandte Physik, Universität Tübingen, Tübingen, Germany — 2Institut für Festkörperforschung, Forschungszentrum Jülich, Jülich, Germany — 3Institut Laue Langevin, Grenoble, France
We have investigated static and dynamic properties of aqueous solutions of bovine serum albumin (BSA) in an integrated conceptual framework, combining static and dynamic light scattering (SLS/DLS) and small-angle X-ray scattering (SAXS) with colloid theory. We focus on solutions with sodium and calcium chloride, which are physiologically relevant and well-suited for effective modelling. Using a new theoretical approach, we are able to reproduce the measured collective diffusion constant and structure factor, up to volume fractions of 5-10% [1]. By tuning the ionic strength, we quantify the effect of macromolecular crowding along the crossover from charge- to sterically stabilized protein solutions. Moreover, we test the validity of various generalized Stokes-Einstein equations (GSE), which connect osmotic compressibility, diffusion constant, and viscosity of complex liquids. We find that, despite their appealing simplicity, the GSE schemes fail to capture the essential richness of macromolecular collective diffusion.
[1] M. Heinen et al., J. Appl. Cryst., 2010, 43, 970-980.