Revival of collective water structure and dynamics in reverse micelles brought about by protein encapsulation

Phys Chem Chem Phys. 2018 Sep 12;20(35):22932-22945. doi: 10.1039/c8cp03422b.

Abstract

In this computational study, we investigate the behaviour of a protein in water encapsulated in a zwitterionic/neutral reverse micelle as a cellular mimetic. Addressing the discussion if current force fields are apt to correctly describe crowded/encapsulated environments, we apply an upscaling of the non-bonded, non-electrostatic interactions of protein and/or surfactants with the water component. Based on the thorough analysis of single-particle rotational motion of water and ubiquitin molecules we find retardation near the interfaces and a bulk-like core. This single-particle analysis is contrasted with the study of collective micellar structure and dynamics. We report a novel mechanism of depolarization inside the RM under the general LeChatelier principle of reverse micelle adaptation to the surrounding low-dielectric immersion medium. The relation of this mechanism to other mechanisms of minimum polarization in RMs is discussed.

MeSH terms

  • Kinetics
  • Micelles
  • Molecular Dynamics Simulation
  • Molecular Structure
  • Particle Size
  • Succinates / chemistry
  • Surface-Active Agents / chemistry
  • Thermodynamics
  • Ubiquitin / chemistry*
  • Water / chemistry*

Substances

  • Micelles
  • Succinates
  • Surface-Active Agents
  • Ubiquitin
  • bis(2-ethylhexyl)sulfosuccinate
  • Water