Fast-tumbling bicelles constructed from native Escherichia coli lipids
Journal article, 2016
Solution-state NMR requires small membrane mimetic systems to allow for acquiring high-resolution data. At the same time these mimetics should faithfully mimic biological membranes. Here we characterized two novel fast-tumbling bicelle systems with lipids from two Escherichia coli strains. While strain 1 (AD93WT) contains a characteristic E. coli lipid composition, strain 2 (AD93-PE) is not capable of synthesizing the most abundant lipid in E. coli, phosphatidylethanolamine. The lipid and acyl chain compositions were characterized by P-31 and C-13 NMR. Depending on growth temperature and phase, the lipid composition varies substantially, which means that the bicelle composition can be tuned by using lipids from cells grown at different temperatures and growth phases. The hydrodynamic radii of the bicelles were determined from translational diffusion coefficients and NMR spin relaxation was measured to investigate lipid properties in the bicelles. We find that the lipid dynamics are unaffected by variations in lipid composition, suggesting that the bilayer is in a fluid phase under all conditions investigated here. Backbone glycerol carbons are the most rigid positions in all lipids, while head-group carbons and the first carbons of the acyl chain are somewhat more flexible. The flexibility increases down the acyl chain to almost unrestricted motion at its end. Carbons in double bonds and cyclopropane moieties are substantially restricted in their motional freedom. The bicelle systems characterized here are thus found to faithfully mimic E. coli inner membranes and are therefore useful for membrane interaction studies of proteins with E. coli inner membranes by solution-state NMR. (C) 2016 Elsevier B.V. All rights reserved.
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model membrane
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magnetic-resonance relaxation
journal of chemical physics
Lipid composition
isotropic bicelles
mendoza d
translational diffusion
pressure resistance
phospholipid bicelles
v42
cyclopropane fatty-acids
micellar-solutions
trends in biochemical sciences
ejskal eo
Biochemistry & Molecular Biology
Diffusion
Model-free approach
cardiolipin
system
Biophysics
journal of biological chemistry
Dynamics
chavigny a
Inner membrane
growth-phase
synthesis
1991
p5323
Author
J. Liebau
Stockholm University
P. Pettersson
Stockholm University
P. Zuber
Stockholm University
Candan Ariöz
Chalmers, Biology and Biological Engineering, Chemical Biology
L. Maler
Stockholm University
Biochimica et Biophysica Acta - Biomembranes
0005-2736 (ISSN) 1879-2642 (eISSN)
Vol. 1858 9 2097-2105Subject Categories
Biophysics
DOI
10.1016/j.bbamem.2016.06.008
PubMed
27317394