Abstract
Water near extended hydrophobic surfaces is like that
at a liquid–vapor
interface, where fluctuations in water density are substantially enhanced
compared to those in bulk water. Here we use molecular simulations
with specialized sampling techniques to show that water density fluctuations
are similarly enhanced, even near hydrophobic surfaces of complex
biomolecules, situating them at the edge of a dewetting transition.
Consequently, water near these surfaces is sensitive to subtle changes
in surface conformation, topology, and chemistry, any of which can
tip the balance toward or away from the wet state and thus significantly
alter biomolecular interactions and function. Our work also resolves
the long-standing puzzle of why some biological surfaces dewet and
other seemingly similar surfaces do not.