Evidence for Leaflet-Dependent Redistribution of Charged Molecules in Fluid Supported Phospholipid Bilayers

Center for Integrated Nanotechnologies, Materials Physics and Applications Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA.
Langmuir (Impact Factor: 4.38). 12/2008; 24(23):13250-3. DOI: 10.1021/la802909c
Source: PubMed

ABSTRACT The asymmetric distribution of charged molecules between the leaflets of solid-substrate-supported phospholipid bilayers is studied using imaging ellipsometry, fluorescence microscopy, and numerical solutions of the Poisson-Boltzmann equation. Experiments are facilitated by the use of patterned substrates that allow for side-by-side comparison of lipid monolayers and supported bilayers. On silica surfaces, negatively charged lipid components are shown to be enriched in the outer leaflet of a supported bilayer system at modest salt concentrations. The approaches developed provide a general means for determining asymmetries of charged components in supported lipid bilayers.

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