Balbach/Saalwächter
The human eye lens contains a mixture of crystallin proteins at an exceptionally high concentration. The aim of the project was to study the stability of these protein solutions and to gain molecular insights into cataract formation. Towards this end, mainly NMR methods were applied to differentiate between phase separation, denaturation, and/or unspecific aggregation in concentrated crystallin samples and possible amyloid formation, the latter leading to more defined and constrained structures. The project started with model proteins and applied the developed methods in the second funding period to crystallins. These were obtained recombinantly as well as from bovine lenses and human lens homogenates from cataract patients. We deepened their physical understanding about the molecular processes that prevented or stimulated cataract formation. We extended the control of molecular ordering at various levels including pathogenic point mutations of single amino acids in certain crystallins, single crystallins at very high concentrations without or with other guest proteins, the composition of different crystallin mixtures at various concentrations up to stable or cataract-forming eye lens systems. The established methods to study the translational and rotational protein dynamics and interactions between individual crystallins at amino acid resolution were then applied to the formation of highly molecular ordered amyloid fibrils, UV induced aggregation, and the formation of hydrogels, which were all observed in crystallin solutions. The goal was to understand the intermolecular interactions underlying the polymer properties of the eye lens proteins.
Highlighted Publications:
- M. Roos, M. Ott, M. Hofmann, S. Link, E. Rössler, J. Balbach, A. Krushelnitsky, and K. Saalwächter, Coupling and Decoupling of Rotational and Translational Diffusion of Proteins under Crowding Conditions J. Am. Chem. Soc. 138, 10365–10372 (2016)
- M. Roos, S. Link, J. Balbach, A. Krushelnitsky, and K. Saalwächter , NMR-Detected Brownian Dynamics of αB-Crystallin over a Wide Range of Concentrations Biophys. J. 108, 98 (2015)
- Susanne Weininger, Malte Neudorf, Stefan Gröger, Eric Plato, Robert Broneske, Kay Saalwächter, Ulrich Weininger, Jochen Balbach, Early Stage UV-B Induced Molecular Modifications of Human Eye Lens γD-Crystallin. Macromolecular Bioscience