Mirror-image antiparallel β-sheets organize water molecules into superstructures of opposite chirality.

Autor: Perets EA; Department of Chemistry, Yale University, New Haven, CT 06520., Konstantinovsky D; Department of Chemistry, Yale University, New Haven, CT 06520.; Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06520., Fu L; Department of Chemistry, Yale University, New Haven, CT 06520., Chen J; Department of Chemistry, Yale University, New Haven, CT 06520.; Faculty of Materials Science and Engineering, South China University of Technology, 510640 Guangzhou, China., Wang HF; Department of Chemistry and Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Fudan University, Shanghai 200433, China.; School of Science, Westlake University, 310024 Hangzhou, China., Hammes-Schiffer S; Department of Chemistry, Yale University, New Haven, CT 06520; sharon.hammes-schiffer@yale.edu elsa.yan@yale.edu., Yan ECY; Department of Chemistry, Yale University, New Haven, CT 06520; sharon.hammes-schiffer@yale.edu elsa.yan@yale.edu.
Jazyk: angličtina
Zdroj: Proceedings of the National Academy of Sciences of the United States of America [Proc Natl Acad Sci U S A] 2020 Dec 29; Vol. 117 (52), pp. 32902-32909. Date of Electronic Publication: 2020 Dec 14.
DOI: 10.1073/pnas.2015567117
Abstrakt: Biomolecular hydration is fundamental to biological functions. Using phase-resolved chiral sum-frequency generation spectroscopy (SFG), we probe molecular architectures and interactions of water molecules around a self-assembling antiparallel β-sheet protein. We find that the phase of the chiroptical response from the O-H stretching vibrational modes of water flips with the absolute chirality of the (l-) or (d-) antiparallel β-sheet. Therefore, we can conclude that the (d-) antiparallel β-sheet organizes water solvent into a chiral supermolecular structure with opposite handedness relative to that of the (l-) antiparallel β-sheet. We use molecular dynamics to characterize the chiral water superstructure at atomic resolution. The results show that the macroscopic chirality of antiparallel β-sheets breaks the symmetry of assemblies of surrounding water molecules. We also calculate the chiral SFG response of water surrounding (l-) and (d-) LK 7 β to confirm the presence of chiral water structures. Our results offer a different perspective as well as introduce experimental and computational methodologies for elucidating hydration of biomacromolecules. The findings imply potentially important but largely unexplored roles of water solvent in chiral selectivity of biomolecular interactions and the molecular origins of homochirality in the biological world.
Competing Interests: The authors declare no competing interest.
Databáze: MEDLINE
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