Hydrated Excess Protons Can Create Their Own Water Wires
Yuxing Peng1, Jessica M J Swanson1, Seung-gu Kang2
1†Department of Chemistry, James Franck Institute, Computation Institute, The University of Chicago, 5735 South Ellis Avenue, Chicago, Illinois 60637, United States.
The Journal of Physical Chemistry. B
|November 5, 2014
Summary
Protons can create their own water pathways through hydrophobic environments, unlike other ions. This self-wetting mechanism facilitates proton transport, suggesting a new understanding of biological proton translocation.
Area of Science:
- Physical Chemistry
- Biophysics
- Materials Science
Background:
- Proton transport via Grotthuss shuttling in water networks is well-studied.
- The role of water structure in facilitating proton migration is critical.
Purpose of the Study:
- To investigate a novel mechanism of proton transport involving water molecule movement.
- To explore how excess protons interact with hydrophobic environments during translocation.
Main Methods:
- Reactive molecular dynamics simulations were employed.
- Proton transport through a hydrophobic nanotube was modeled.
Main Results:
- Excess protons actively "shoot" water molecules into dry hydrophobic spaces, creating a water wire.
- This self-generated water wire facilitates subsequent proton migration and lowers the energy barrier.
- Unlike protons, other cations like K(+) block wetting and dry out the nanotube.
Conclusions:
- Protons can initiate wetting in hydrophobic regions, creating their own pathways for transport.
- This proton-induced wetting mechanism is crucial for understanding proton translocation in biological systems.
- Pre-existing water wires are not essential for proton transport through hydrophobic channels.
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