Structure, dynamics, and hydration of POPC/POPS bilayers suspended in NaCl, KCl, and CsCl solutions

Jurkiewicz, Piotr
Cwiklik, Lukasz
Vojtíšková, Alžběta
Jungwirth, Pavel
Hof, Martin

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Publication date

March 2012

DOI

10.1016/j.bbamem.2011.11.033

Publisher

Elsevier B.V.

ISSN

0005-2736

Citation count (estimate)

Abstract

AbstractEffects of alkali metal chlorides on the properties of mixed negatively charged lipid bilayers are experimentally measured and numerically simulated. Addition of 20mol% of negatively charged phosphatidylserine to zwitterionic phosphatidylcholine strengthens adsorption of monovalent cations revealing their specificity, in the following order: Cs+<K+<Na+. Time-resolved fluorescence solvent relaxation shows significant decrease both in mobility and hydration of the lipid carbonyls probed by Laurdan upon addition of the cations. The experimental findings are supported by molecular dynamics simulations, which show deep penetration of the cations down to the glycerol level of the lipid bilayer where they pair with oxygen atoms of carbonyl...