Sitting at the edge: How biomolecules use hydrophobicity to tune their interactions and function

TL;DR

This study uses molecular simulations to demonstrate that water density fluctuations near biomolecular hydrophobic surfaces are enhanced, influencing biomolecular interactions and functions by being sensitive to surface changes, and explaining dewetting phenomena.

Contribution

It reveals how water fluctuations near complex biomolecular surfaces are enhanced, affecting interactions and resolving the dewetting puzzle.

Findings

Water density fluctuations are enhanced near hydrophobic biomolecular surfaces.

Surface conformation and chemistry can tip the wetting balance.

The work explains why some biological surfaces dewet while others do not.

Abstract

Water near hydrophobic surfaces is like that at a liquid-vapor interface, where fluctuations in water density are substantially enhanced compared to that 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 towards 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.