Pressure and Osmolyte Effects on Liquid-Liquid Phase Separation Phenomena and Condensates of Proteins
Final Report Abstract
The aim of the project was to study the combined effects of temperature, pressure and naturally occurring osmolytes on liquid-liquid phase separation (LLPS) phenomena of different types of proteins, focusing also on the effect of extreme environmental conditions, such as high pressure up to the kbar-regime. LLPS phenomena have been recognized to play an important role in the membrane-less compartmentalization of cells through the formation of biomolecular condensates. We employed various spectroscopy (UV/Vis, FTIR, fluorescence) and microscopy techniques to reveal structural changes and mesoscopic phase states of the systems. We found, quite unexpectedly, that some LLPS systems are very pressure sensitive. Pressures in the tens and hundreds of bar range are already sufficient to alter LLPS and droplet transitions. This observation suggests, in general, that organisms thriving at high-pressure conditions in the deep sea have to cope with this high pressure-sensitivity of biomolecular condensates. We found that particular cosolvents, such as the seep-sea osmolyte trimethylamine-N-oxide (TMAO), an osmolyte upregulated in deep-sea fish, and macromolecular crowding significantly increase the stability of the condensed protein droplets, pointing to a previously unrecognized aspect of the adaptive advantage of increased concentrations of osmolytes in deep-sea organisms. In collaboration with a theory group (Prof. Dr. H. S. Chan, Toronto, Canada), we were able to achieve a mechanistic and molecular-level understanding of the processes involved, in particular on the role of electrostatic and hydrophobic interactions, hydration and void volume in controlling LLPS phenomena at high pressures. In the final step, we explored the effectiveness of protein droplets in modulating the conformational dynamics of peptides and nucleic acids in such biomolecular condensates.
Publications
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Pressure-Sensitive and Osmolyte-Modulated Liquid–Liquid Phase Separation of Eye-Lens γ-Crystallins. Journal of the American Chemical Society, 141(18), 7347-7354.
Cinar, Süleyman; Cinar, Hasan; Chan, Hue Sun & Winter, Roland
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Pressure Sensitivity of SynGAP/PSD‐95 Condensates as a Model for Postsynaptic Densities and Its Biophysical and Neurological Ramifications. Chemistry – A European Journal, 26(48), 11024-11031.
Cinar, Hasan; Oliva, Rosario; Lin, Yi‐Hsuan; Chen, Xudong; Zhang, Mingjie; Chan, Hue Sun & Winter, Roland
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Biomolecular Condensates under Extreme Martian Salt Conditions. Journal of the American Chemical Society, 143(13), 5247-5259.
Fetahaj, Zamira; Ostermeier, Lena; Cinar, Hasan; Oliva, Rosario & Winter, Roland
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Effects of Cosolvents and Crowding Agents on the Stability and Phase Transition Kinetics of the SynGAP/PSD-95 Condensate Model of Postsynaptic Densities. The Journal of Physical Chemistry B, 126(8), 1734–1741.
Cinar, Hasan; Oliva, Rosario; Wu, Haowei; Zhang, Mingjie; Chan, Hue Sun & Winter, Roland
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Harnessing Pressure-Axis Experiments to Explore Volume Fluctuations, Conformational Substates, and Solvation of Biomolecular Systems. The Journal of Physical Chemistry Letters, 13(51), 12099-12115.
Oliva, Rosario & Winter, Roland
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Suppression of Liquid‐Liquid Phase Separation and Aggregation of Antibodies by Modest Pressure Application. Chemistry – A European Journal, 28(48).
Fetahaj, Zamira; Jaworek, Michel W.; Oliva, Rosario & Winter, Roland
