Mechanical Unfolding of Spectrin Repeats Induces Water-Molecule Ordering.

摘要: Abstract Mechanical processes are involved at many stages of the development living cells, and often external forces applied to a biomolecule result in its unfolding. Although our knowledge unfolding mechanisms magnitude has evolved, role that water molecules play mechanical biomolecules not yet been fully elucidated. To this end, we investigated with steered molecular dynamics simulations dystrophin’s spectrin repeat 1 related changes protein’s structure ordering surrounding molecules. Our results indicate upon mechanically induced protein, solvent become more ordered increase their average number hydrogen bonds. In addition, unfolded structures originating from pulling expose an increasing amount hydrophobic residues molecules, uncoiled regions adapt convex surface small radius curvature. As result, reorganize around protrusions structurally waters characteristic so-called “small-molecule regime,” which allows maintain high bond count expense increased structural order. We also determined response protein is localized specific undergo These plays important biomolecules. findings may prove relevant ever-growing interest understanding macromolecular crowding cells effects on folding, suggest hydration layer be exploited as means for short-range allosteric communication.