Referenced in: none

Automatically associated channels: Kir2.3

Title: Polarized Water Wires under Confinement in Chiral Channels.

Authors: Mihail Barboiu, Pierre-André Cazade, Yann Le Duc, Yves-Marie Legrand, Arie Van der Lee, Benoit Coasne

Journal, date & volume: J Phys Chem B, 2015 Jul 16 , 119, 8707-17

PubMed link: http://www.ncbi.nlm.nih.gov/pubmed/26090910

Abstract
The alignment of water molecules along chiral pores may activate proton/ion conduction along dipolar hydrophilic pathways. Here we show that a simple synthetic "T-channel" forms a directional pore with its carbonyl moieties solvated by chiral helical water wires. Atom-scale simulations and experimental crystallographic assays reveal a dynamical structure of water and electrolyte solutions (alkali metal chlorides) confined in these organic T-channels. Oscillations in the dipole orientation, which correspond to alternative ordering (dipole up-dipole down) of the water molecules with a period of about 4.2 Å (imposed by the distance between two successive carbonyl groups) are observed. When ions are added to the system, despite the strong Coulombic water/ion interaction, confined water remains significantly ordered in the T-channel and still exhibits surface-induced polarization. Cation permeation can be achieved through alternated hydration-dehydration occurring along strongly oriented water wires. The T-channel, which exhibits chirality with strong water orientation, provides an opportunity to unravel novel water-channel systems that share many interesting properties of biomolecular systems.