Počet záznamů: 1  

Does fluoride disrupt hydrogen bond network in cationic lipid bilayer? Time-dependent fluorescence shift of Laurdan and molecular dynamics simulations

  1. 1.
    0433922 - UFCH-W 2015 RIV US eng J - Článek v odborném periodiku
    Pokorná, Šárka - Jurkiewicz, Piotr - Vazdar, M. - Cwiklik, Lukasz - Jungwirth, Pavel - Hof, Martin
    Does fluoride disrupt hydrogen bond network in cationic lipid bilayer? Time-dependent fluorescence shift of Laurdan and molecular dynamics simulations.
    Journal of Chemical Physics. Roč. 141, č. 22 (2014), 22D516. ISSN 0021-9606
    Grant CEP: GA ČR GBP208/12/G016
    Institucionální podpora: RVO:61388955 ; RVO:61388963
    Klíčová slova: fluorescence sfifts * Cationic lipids * Hydrogen bond networks
    Kód oboru RIV: CF - Fyzikální chemie a teoretická chemie
    Impakt faktor: 2.952, rok: 2014

    Time-dependent fluorescence shift (TDFS) of Laurdan embedded in phospholipid bilayers reports on hydration and mobility of the phospholipid acylgroups. Exchange of H2O with D2O prolongs the lifetime of lipid-water and lipid-water-lipid interactions, which is reflected in a significantly slower TDFS kinetics. Combining TDFS measurements in H2O and D2O hydrated bilayers with atomistic molecular dynamics (MD) simulations provides a unique tool for characterization of the hydrogen bonding at the acylgroup level of lipid bilayers. In this work, we use this approach to study the influence of fluoride anions on the properties of cationic bilayers composed of trimethylammonium-propane (DOTAP). The results obtained for DOTAP are confronted with those for neutral phosphatidylcholine (DOPC) bilayers. Both in DOTAP and DOPC H2O/D2O exchange prolongs hydrogen-bonding lifetime and does not disturb bilayer structure. These results are confirmed by MD simulations. TDFS experiments show, however, that for DOTAP this effect is cancelled in the presence of fluoride ions. We interpret these results as evidence that strongly hydrated fluoride is able to steal water molecules that bridge lipid carbonyls. Consequently, when attracted to DOTAP bilayer, fluoride disrupts the local hydrogen-bonding network, and the differences in TDFS kinetics between H2O and D2O hydrated bilayers are no longer observed. A distinct behavior of fluoride is also evidenced by MD simulations, which show different lipid-ion binding for Cl− and F−.
    Trvalý link: http://hdl.handle.net/11104/0238095