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

• DOI: 10.1073/pnas.2015567117
• Publication Date: 2020-12-16T22:43:42Z
• Authors: Ethan A. Perets; Daniel Konstantin...; Li Fu; Jiantao Chen; Hong-Fei Wang; Sharon Hammes-Sch...; Elsa C. Y. Yan
• Keywords: Protein Folding; Lysine; Water; Molecular Dynamics Simulation; 01 natural sciences; 0104 chemical sciences; Isomerism; Leucine; Protein Conformation, beta-Strand; Protein Multimerization; Hydrophobic and Hydrophilic Interactions; Oligopeptides

Significance

The structure and function of biomacromolecules depend on water structures in the hydration shell. We perform experiments and computations to examine the water molecules around an antiparallel β-sheet. Our experiments show that the sign of chiral optical responses of water reverses when the β-sheet is an ( l -) or a ( d -) enantiomer. Molecular modeling reveals a chiral topology of water assembled around the β-sheet. These results suggest that mirror-image proteins organize water molecules into supermolecular structures of opposite chirality. Hence, a complete description of biomacromolecular chirality must include the surrounding water molecules. This finding invites a new line of inquiry about the role of water in chiral selectivity of biomolecular interactions and the molecular origins of homochirality in the biological world.