Lipid hydration and mobility: An interplay between fluorescence solvent relaxation experiments and molecular dynamics simulations

0375917 - ÚFCH JH 2013 RIV FR eng J - Journal Article
Jurkiewicz, Piotr - Cwiklik, Lukasz - Jungwirth, Pavel - Hof, Martin
Lipid hydration and mobility: An interplay between fluorescence solvent relaxation experiments and molecular dynamics simulations.
Biochimie. Roč. 94, č. 1 (2012), s. 26-32. ISSN 0300-9084. E-ISSN 1638-6183
R&D Projects: GA MŠMT(CZ) LC06063; GA ČR GA203/08/0114; GA MŠMT LC512
Institutional research plan: CEZ:AV0Z40400503; CEZ:AV0Z40550506
Keywords : sn-1 acyl group * Laurdan * oxidized phospholipids
Subject RIV: CF - Physical ; Theoretical Chemistry
Impact factor: 3.142, year: 2012

Fluorescence solvent relaxation experiments are based on the characterization of time-dependent shifts in the fluorescence emission of a chromophore, yielding polarity and viscosity information about the chromophore's immediate environment. A chromophore applied to a phospholipid bilayer at a well-defined location (with respect to the z-axis of the bilayer) allows monitoring of the hydration and mobility of the probed segment of the lipid molecules. Specifically, time-resolved fluorescence experiments, fluorescence quenching data and molecular dynamic (MD) simulations show that 6-lauroyl-2-dimethylaminonaphthalene (Laurdan) probes the hydration and mobility of the sn-1 acyl groups in a phosphatidylcholine bilayer. The time-dependent fluorescence shift (TDFS) of Laurdan provides information on headgroup compression and expansion induced by the addition of different amounts of cationic lipids to phosphatidylcholine bilayers. Those changes were predicted by previous MD simulations. Addition of truncated oxidized phospholipids leads to increased mobility and hydration at the sn-1 acyl level. This experimental finding can be explained by MD simulations, which indicate that the truncated chains of the oxidized lipid molecules are looping back into aqueous phase, hence creating voids below the glycerol level. Fluorescence solvent relaxation experiments are also useful in understanding salt effects on the structure and dynamics of lipid bilayers.
Permanent Link: http://hdl.handle.net/11104/0208455