Dresden 2017 – wissenschaftliches Programm
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BP: Fachverband Biologische Physik
BP 24: Posters - Protein Structure and Dynamics
BP 24.15: Poster
Dienstag, 21. März 2017, 14:00–16:00, P1A
Temperature dependence of the self-diffusion of BSA in solution with trivalent ions — •Christian Beck1,2, Michal Braun1, Marco Grimaldo2, Niina H. Jalavaro3, Felix Roosen-Runge2, Fajun Zhang1, Tilo Seydel2, and Frank Schreiber1 — 1Institut für Angewandte Physik, Universität Tübingen, 72076 Tübingen — 2Institut Laue-Langevin, Grenoble, France — 3Neutron Sciences Directorate, Oak Ridge National Laboratory, USA
Recent studies focused on the salt-induced slowing down of the short-time self-diffusion of bovine serum albumin (BSA) in aqueous solutions (D2O) at constant temperature [1] using quasi-elastic neutron scattering. The diffusion coefficients of the clusters, induced by the presence of trivalent yttrium ions, can be described independently of the protein concentration as a function of the ratio of salt ions per protein.
With experiments at BASIS (SNS, ONRL, Oak Ridge, TN) we determined the temperature-dependence of the system. For each temperature, a master curve is observed.
In samples with trivalent salts, the diffusion coefficients increase less with increasing temperature than predicted by the Stokes-Einstein relation.
The different master curves were used to determine the temperature dependent binding probabilities between the proteins using the Flory-Stockmeyer theory.
An increasing binding probability with increasing salt concentration and increasing temperature was found.
This observation on the microscopic scale is in agreement with the observed lower critical solution temperature (LCST) on macroscopic scale.
M.Grimaldo et al. J. Phys. Chem. Letters, 6 (2015) 2577