Liquid-liquid phase separation and crystallization in protein solutions induced by multivalent metal ions
Zusammenfassung der Projektergebnisse
We have performed a systematic and successful research on tuning protein interactions and phase behavior in solution using charges, in particularly the metastable liquid-liquid phase separation and its role on protein crystallization. Small angle X-ray or neutron scattering together with the liquid state theoretical approach were employed to characterize the effective interactions in protein solutions. Interactions as a function of protein concentration, ionic strength, and the nature of salt can be readily characterized using a suitable model potential. Using trivalent metal ions, for the first time, we discovered the reentrant condensation in protein solutions, which might be a rather universal behavior for acidic proteins. An analytical model has been developed for charge regulation by taking into account ion condensation, metal ion hydrolysis and interaction with charged amino acid side chains on the protein surface. Within the condensed regime, protein solutions can undergo metastable liquid-liquid phase separation, clustering, and protein crystallization, which further demonstrate the tunable interactions in protein solutions using charge. This rich phase behavior can be rationalized using an ion-activated patchy colloid model. Furthermore, the application of the framework on protein crystallization have shown that the tunable phase behavior can be used to optimize growth conditions for high quality protein single crystals, which can potentially apply to all acidic proteins. Systematic studies on the nucleation and crystal growth kinetics under various conditions provide deep insight of the classical and nonclassical pathways for protein crystallization, such as a two-step crystallization via a metastable LLPS. Recent progress using real-time SAXS and optical microscopy has revealed unique structural features and the growth kinetics of the nonclassical nucleation mechanism. The effect of tunable phase behavior in protein solutions using metal ions has potentially far reaching consequences for a broad range of issues from protein crystallization to proteincondensation related diseases and the structural organization in living cells.
Projektbezogene Publikationen (Auswahl)
- Charge-controlled metastable liquid-liquid phase separation in protein solutions as a universal pathway towards crystallization. Soft Matter 2012 8, 1313-1316
F. Zhang, R. Roth, M. Wolf, F. Roosen-Runge, M. W. A. Skoda, R. M. J. Jacobs, R. Roth, M. Sztucki, F. Schreiber
(Siehe online unter https://doi.org/10.1039/c2sm07008a) - (2013) Salt Effects in Protein Solutions. Institut für Angewandte Physik, PhD Dissertation. Universität Tübingen
Roosen-Runge F.
- (2014) Effective interactions in LLPS protein solutions induced by multivalent ions. Institut für Angewandte Physik, PhD Dissertation. Universität Tübingen
Wolf M.
(Siehe online unter https://dx.doi.org/10.15496/publikation-4822) - Ion-activated attractive patches as a mechanism for controlled protein interactions. Scientific Reports 2014, 4, 7016
F. Roosen-Runge, F. Zhang, F. Schreiber, R. Roth
(Siehe online unter https://doi.org/10.1038/srep07016) - Nonclassical pathways of protein crystallization in the presence of multivalent metal ions. Crystal Growth & Design, 2014, 14(12), 6357-6366
A. Sauter, M. Oelker, G. Zocher, F. Zhang, T. Stehle, F. Schreiber
(Siehe online unter https://doi.org/10.1021/cg501099d) - Protein cluster formation in aqueous solution in the presence of multivalent metal ions - a light scattering study. Soft Matter 2014, 10, 894-902
D. Soraruf, F. Roosen-Runge, M. Grimaldo, F. Zanini, R. Schweins, T. Seydel, F. Zhang, R. Roth, M. Oettel, F. Schreiber
(Siehe online unter https://doi.org/10.1039/c3sm52447g) - Reentrant condensation, liquid-liquid phase separation and crystallization in protein solutions induced by multivalent metal ions. Pure Appl. Chem. 2014, 86(2), 191-202
F. Zhang, F. Roosen-Runge, A. Sauter, M. Wolf, R.M.J. Jacobs, F. Schreiber
(Siehe online unter https://doi.org/10.1515/pac-2014-5002) - (2015) Protein crystallization induced by multivalent metal salts. Institut für Angewandte Physik, PhD Dissertation. Universität Tübingen
Sauter A.
- On the question of two-step nucleation in protein crystallization. Faraday Discussions. 2015, 179, 41-58
A. Sauter, M. Oelker, G. Zocher, F. Zhang, T. Stehle , F. Schreiber
(Siehe online unter https://doi.org/10.1039/c4fd00225c) - Real-time observation of non-classical protein crystallization kinetics. J. Am. Chem. Soc. 2015, 137(4), 1485-1491
A. Sauter, F. Roosen-Runge, F. Zhang, G. Lotze, R.M.J. Jacobs, F. Schreiber
(Siehe online unter https://doi.org/10.1021/ja510533x)
