Dresden 2017 – wissenschaftliches Programm
CPP 51.5: Poster
Mittwoch, 22. März 2017, 18:30–21:00, P3
Solvent isotope effect on protein phase behavior in aqueous protein solutions — •Michal K. Braun1, Marcell Wolf1, Olga Matsarskaia1, Stefano Da Vela1, Felix Roosen-Runge2, Michael Sztucki3, Roland Roth4, Fajun Zhang1, and Frank Schreiber1 — 1Institut für Angewandte Physik, Universität Tübingen, 72076 Tübingen — 2ILL, Grenoble, France — 3ESRF, Grenoble, France — 4Institut für Theoretische Physik, Universität Tübingen
Knowledge about interactions and phase behavior of proteins in aqueous solutions is crucial in fields like protein crystallization, drug design and treatment of diseases. For many spectroscopic techniques in protein science D2O is commonly used instead of H2O in order to improve the signal. Here we present our finding of a strong solvent isotope effect on the protein phase behavior and the effective interactions in solutions of bovine serum albumin (BSA) with trivalent salts . At intermediate salt concentrations the phase diagram exhibits a regime where condensation occurs . This regime is significantly broadend when H2O is replaced by D2O. The lower critical solution temperature of liquid-liquid phase separation decreases significantly when D2O is added to the solvent. Small angle x-ray scattering (SAXS) data shows that the reduced second virial coefficient is lower in D2O than in H2O. Both the macroscopic observations as well as the microscopic results consistently show that the attraction between the protein molecules increases when H2O is replaced by D2O.
Braun et al., in preparation
Zhang et al., Pure Appl. Chem., 86, 191, 2014