Direct imaging of salt effects on lipid bilayer ordering at sub-molecular resolution

Ferber, Urs M.; Kaggwa, Gillian; Jarvis, Suzanne P.

doi:10.1007/s00249-010-0650-7

Cited by 31 publications

(29 citation statements)

References 44 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…47 The binding of cations has a significant impact on the structural and dynamical properties of PC membranes. 45,48 A decrease of area per lipid and lipid lateral diffusion coefficient as an increase of salt concentration had been shown in MD simulations 45,48,53 in agreement with the decrease of the angle between the P−N 54 did not find a significant change in area per lipid, though tilting of the lipids' head groups out of the membrane plane was noted.…”

Section: ■ Introductionsupporting

confidence: 57%

Molecular Dynamics Study of Oxidized Lipid Bilayers in NaCl Solution

2013

View full text Add to dashboard Cite

Polyunsaturated lipids are major targets of free radicals forming oxidized lipids through the lipid peroxidation process. Thus, oxidized lipids play a significant role in cell membrane damage. Using atomistic molecular dynamics (MD) simulations to investigate the dynamics of oxidized lipid bilayers, we examined the effects of NaCl on them. Lipid bilayer systems of 1-palmitoyl-2-linoleoyl-sn-glycero-3-phosphatidylcholine (PLPC) and 4 oxidation products, namely, 9-tc-hydroperoxide linoleic acid, 13-tc-hydroperoxide linoleic acid, 9-oxononanoic acid, and 12-oxo-9-didecadienoic acid in 0, 0.06, and 1 M NaCl solution were studied. These 51 systems, combined over 15 μs of total simulation time, show Cl(-) anions remaining in the water phase and Na(+) cations permeating into the headgroup region of the bilayer leading to membrane packing. The effects of NaCl on thickness and area per molecule were found to be independent of the concentration of oxidized lipids. NaCl disturbed the bilayers with aldehyde lipids more than those with peroxide lipids. The key finding is that oxidized lipids bend their polar tails toward the water interface. This behavior was monitored by following the time evolution of hydrogen bonds between the oxidized functional groups of different lipids, and the concomitant increase of hydrogen bonds between oxidized functional groups and water molecules. Our results also show that the number of hydrogen bonds should be considered as an equilibration parameter: Very long simulations are needed to equilibrate systems with high NaCl concentrations.

show abstract

Section: ■ Introductionsupporting

confidence: 57%

Molecular Dynamics Study of Oxidized Lipid Bilayers in NaCl Solution

2013

View full text Add to dashboard Cite

show abstract

“…Molecular Dynamic simulations of the effects of monovalent ions on phospholipid bilayers revealed that the effect of the ions on the structure of the bilayer depends on the tendency of specific headgroups to form both intraand extra-molecular hydrogen bonds and on the specific ion at issue (Gurtovenko and Vattulainen, 2008). However, it should be noted that, in some cases, results from MD simulations and corresponding experimental data lack in consistency (Ferber et al, 2011). It is evident that the effect of ions should strongly depend on the overall charge in lipid headgroups, being strongest for more charged lipids.…”

Section: Overview Of the Force Spectroscopy Studies On Supported Lipimentioning

confidence: 90%

Nanoscale mechanical properties of lipid bilayers and their relevance in biomembrane organization and function

Alessandrini

Facci

2012

Micron

View full text Add to dashboard Cite

The mechanical properties of biological systems are emerging as fundamental in determining their functional activity. For example, cells continuously probe their environment by applying forces and, at the same time, are exposed to forces produced by the same environment. Also in biological membranes, the activity of membrane related proteins are affected by the overall mechanical properties of the hosting environment. Traditionally, the mesoscopic mechanical properties of lipid bilayers have been studied by micropipette aspiration techniques. In recent years, the possibility of probing mechanical properties of lipid bilayers at the nanoscale has been promoted by the force spectroscopy potentiality of Atomic Force Microscopes (AFM). By acquiring force-curves on supported lipid bilayers (SLBs) it is possible to probe the mechanical properties on a scale relevant to the interaction between membrane proteins and lipid bilayers and to monitor changes of these properties as a result of a changing environment. Here, we review a series of force spectroscopy experiments performed on SLBs with an emphasis on the functional consequences the measured mechanical properties can have on membrane proteins. We also discuss the force spectroscopy experiments on SLBs in the context of theories developed for dynamic force spectroscopy experiments with the aim to extract the kinetic and energetic description of the process of membrane rupture.

show abstract

“…This conclusion has since been strengthened by further studies showing that bilayer properties remain unaltered upon the addition of sub-molar concentrations of monovalent salt 4,10,11 . Since 2000, however, another view has emerged, suggesting much stronger interactions between phospholipids and monovalent cations, and strong Na + binding in particular [6][7][8][9][12][13][14][15][16][17][18] .…”

Section: Introductionmentioning

confidence: 99%

Molecular electrometer and binding of cations to phospholipid bilayers

Catte

Girych

Javanainen

et al. 2016

Phys. Chem. Chem. Phys.

256

View full text Add to dashboard Cite

Despite the vast amount of experimental and theoretical studies on the binding affinity of cations -especially the biologically relevant Na + and Ca 2+ -for phospholipid bilayers, there is no consensus in the literature. Here we show that by interpreting changes in the choline headgroup order parameters according to the 'molecular electrometer' concept [Seelig et al., Biochemistry, 1987, 26, 7535], one can directly compare the ion binding affinities between simulations and experiments. Our findings strongly support the view that in contrast to Ca 2+ and other multivalent ions, Na + and other monovalent ions (except Li + ) do not specifically bind to phosphatidylcholine lipid bilayers at sub-molar concentrations. However, the Na + binding affinity was overestimated by several molecular dynamics simulation models, resulting in artificially positively charged bilayers and exaggerated structural effects in the lipid headgroups. While qualitatively correct headgroup order parameter response was observed with Ca 2+ binding in all the tested models, no model had sufficient quantitative accuracy to interpret the Ca 2+ :lipid stoichiometry or the induced atomistic resolution structural changes. All scientific contributions to this open collaboration work were made publicly, using nmrlipids.blogspot.fi as the main communication platform.

show abstract

Direct imaging of salt effects on lipid bilayer ordering at sub-molecular resolution

Cited by 31 publications

References 44 publications

Molecular Dynamics Study of Oxidized Lipid Bilayers in NaCl Solution

Molecular Dynamics Study of Oxidized Lipid Bilayers in NaCl Solution

Nanoscale mechanical properties of lipid bilayers and their relevance in biomembrane organization and function

Molecular electrometer and binding of cations to phospholipid bilayers

Contact Info

Product

Resources

About