Lipid Membrane Properties

2016 ◽  
pp. 181-220
Author(s):  
William Stillwell
Keyword(s):  
Lipid Membrane ◽  
Membrane Properties

scholarly journals The Structural Integrity of the Model Lipid Membrane during Induced Lipid Peroxidation: The Role of Flavonols in the Inhibition of Lipid Peroxidation

Antioxidants ◽  
2020 ◽  
Vol 9 (5) ◽  
pp. 430 ◽  
Author(s):  
Anja Sadžak ◽  
Janez Mravljak ◽  
Nadica Maltar-Strmečki ◽  
Zoran Arsov ◽  
Goran Baranović ◽  
...  
Keyword(s):  
Lipid Peroxidation ◽  
Lipid Bilayers ◽  
Lipid Membranes ◽  
Structural Changes ◽  
Structural Integrity ◽  
Lipid Membrane ◽  
Membrane Properties ◽  
Structural Reorganization ◽  
Unsaturated Lipids ◽  
Oxidative Attack

The structural integrity, elasticity, and fluidity of lipid membranes are critical for cellular activities such as communication between cells, exocytosis, and endocytosis. Unsaturated lipids, the main components of biological membranes, are particularly susceptible to the oxidative attack of reactive oxygen species. The peroxidation of unsaturated lipids, in our case 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC), induces the structural reorganization of the membrane. We have employed a multi-technique approach to analyze typical properties of lipid bilayers, i.e., roughness, thickness, elasticity, and fluidity. We compared the alteration of the membrane properties upon initiated lipid peroxidation and examined the ability of flavonols, namely quercetin (QUE), myricetin (MCE), and myricitrin (MCI) at different molar fractions, to inhibit this change. Using Mass Spectrometry (MS) and Fourier Transform Infrared Spectroscopy (FTIR), we identified various carbonyl products and examined the extent of the reaction. From Atomic Force Microscopy (AFM), Force Spectroscopy (FS), Small Angle X-Ray Scattering (SAXS), and Electron Paramagnetic Resonance (EPR) experiments, we concluded that the membranes with inserted flavonols exhibit resistance against the structural changes induced by the oxidative attack, which is a finding with multiple biological implications. Our approach reveals the interplay between the flavonol molecular structure and the crucial membrane properties under oxidative attack and provides insight into the pathophysiology of cellular oxidative injury.

scholarly journals On the Origin of the Anomalous Behavior of Lipid Membrane Properties in the Vicinity of the Chain-Melting Phase Transition

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Alexander Kuklin ◽  
Dmitrii Zabelskii ◽  
Ivan Gordeliy ◽  
José Teixeira ◽  
Annie Brûlet ◽  
...  
Keyword(s):  
Phase Transition ◽  
Lipid Membrane ◽  
Anomalous Behavior ◽  
Membrane Properties

scholarly journals Characterization of Lipid Membrane Properties for Tunable Electroporation

2012 ◽  
Author(s):  
H. Jeremy Cho ◽  
Shalabh C. Maroo ◽  
Evelyn N. Wang
Keyword(s):  
Lipid Bilayers ◽  
Lipid Membrane ◽  
Contact Angle Measurement ◽  
Angle Measurement ◽  
Membrane Properties ◽  
Force Microscopy ◽  
Packing Structure ◽  
Atomic Force ◽  
Dynamics Simulations

Lipid bilayers form nanopores on the application of an electric field. This process of electroporation can be utilized in different applications ranging from targeted drug delivery in cells to nano-gating membrane for engineering applications. However, the ease of electroporation is dependent on the surface energy of the lipid layers and thus directly related to the packing structure of the lipid molecules. 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) lipid monolayers were deposited on a mica substrate using the Langmuir-Blodgett (LB) technique at different packing densities and analyzed using atomic force microscopy (AFM). The wetting behavior of these monolayers was investigated by contact angle measurement and molecular dynamics simulations. It was found that an equilibrium packing density of liquid-condensed (LC) phase DPPC likely exists and that water molecules can penetrate the monolayer displacing the lipid molecules. The surface tension of the monolayer in air and water was obtained along with its breakthrough force.

scholarly journals Escherichia coli response to subinhibitory concentration of Colistin: Insights from study of membrane dynamics and morphology.

2022 ◽  
Author(s):  
Ilanila Ilangumaran Ponmalar ◽  
Jitendriya Swain ◽  
Jaydeep Kumar Basu
Keyword(s):  
Bacterial Infections ◽  
Molecular Mechanisms ◽  
Lipid Membrane ◽  
Membrane Dynamics ◽  
Correlation Spectroscopy ◽  
Membrane Properties ◽  
Bacterial Response ◽  
Lipid Dynamics ◽  
The Impact ◽  
Altered Lipid

Prevalence of wide spread bacterial infections bring forth a critical need in understanding the molecular mechanisms of the antibiotics as well as the bacterial response to those antibiotics. Improper usage of antibiotics, which can be in sub-lethal concentrations is one among the multiple reasons for acquiring antibiotic resistance which makes it vital to understand the bacterial response towards sub-lethal concentrations of antibiotics. In this work, we have used colistin, a well-known membrane active antibiotic used to treat severe bacterial infections and explored the impact of its subminimum inhibitory concentration (MIC) on the lipid membrane dynamics and morphological changes of E. coli. Upon investigation of live cell membrane properties such as lipid dynamics using fluorescence correlation spectroscopy, we observed that colistin disrupts the lipid membrane at sub-MIC by altering the lipid diffusivity. Interestingly, filamentationlike cell elongation was observed upon colistin treatment which led to further exploration of surface morphology with the help of atomic force spectroscopy. The changes in the surface roughness upon colistin treatment provides additional insight on the colistin-membrane interaction corroborating with the altered lipid diffusion. Although altered lipid dynamics could be attributed to an outcome of lipid rearrangement due to direct disruption by antibiotic molecules on the membrane or an indirect consequence of disruptions in lipid biosynthetic pathways, we were able to ascertain that altered bacterial membrane dynamics is due to direct disruptions. Our results provide a broad overview on the consequence of the cyclic polypeptide, colistin on membrane specific lipid dynamics and morphology of a live Gram-negative bacterial cell.

scholarly journals Correlative microscopy reveals the nanoscale morphology of E. coli-derived supported lipid bilayers

2021 ◽  
Author(s):  
Karan Bali ◽  
Zeinab Mohamed ◽  
Anna-Maria Pappa ◽  
Susan Daniel ◽  
Clemens F. Kaminski ◽  
...  
Keyword(s):  
Lipid Bilayers ◽  
Lipid Membrane ◽  
Lipid Vesicles ◽  
Outer Membrane Vesicles ◽  
Atomic Scale ◽  
Membrane Properties ◽  
Supported Lipid Bilayers ◽  
Structured Illumination ◽  
Structured Illumination Microscopy ◽  
Natural And Synthetic

Supported lipid bilayers (SLBs) made from reconstituted lipid vesicles are an important tool in molecular biology. A breakthrough in the field has come with the use of vesicles derived from cell membranes to form SLBs. These new supported bilayers, consisting both of natural and synthetic components, provide a physiologically relevant system on which to study protein-protein interactions as well as protein-ligand interactions and other lipid membrane properties. These complex bilayer systems hold promise but have not yet been fully characterised in terms of their composition, ratio of natural to synthetic component and membrane protein content. Here, we describe a method of correlative atomic force (AFM) with structured illumination microscopy (SIM) for the accurate mapping of complex lipid bilayers that consist of a synthetic fraction and a fraction of lipids derived from Escherichia coli outer membrane vesicles (OMVs). We exploit the enhanced resolution and molecular specificity that SIM can offer to identify areas of interest in these bilayers and the atomic scale resolution that the AFM provides to create detailed topography maps of the bilayers. We are thus able to understand the way in which the two different lipid fractions (natural and synthetic) mix within the bilayers, quantify the amount of bacterial membrane incorporated in the bilayer and directly visualise the interaction of these bilayers with bacteria-specific, membrane-binding proteins. Our work sets the foundation for accurately understanding the composition and properties of OMV-derived SLBs and establishes correlative AFM/ SIM as a method for characterising complex systems at the nanoscale.

Effect of Erythrodiol, A Natural Pentacyclic Triterpene from Olive Oil, on the Lipid Membrane Properties

2015 ◽  
Vol 248 (6) ◽  
pp. 1079-1087 ◽  
Author(s):  
Lamice Habib ◽  
Alia Jraij ◽  
Nathalie Khreich ◽  
Catherine Charcosset ◽  
Hélène Greige-Gerges
Keyword(s):  
Olive Oil ◽  
Lipid Membrane ◽  
Membrane Properties ◽  
Pentacyclic Triterpene

scholarly journals Measuring Lipid Membrane Properties using a Mechanosensitive Fluorescence Probe

2017 ◽  
Vol 112 (3) ◽  
pp. 42a
Author(s):  
Adai Colom Diego ◽  
Marta Dal Molin ◽  
Saeideh Soleimanpour ◽  
Emmanuel Derivery ◽  
Marcos Gonzalez Gaitan ◽  
...  
Keyword(s):  
Lipid Membrane ◽  
Fluorescence Probe ◽  
Membrane Properties

scholarly journals Roughness of a transmembrane peptide reduces lipid membrane dynamics

2016 ◽  
Author(s):  
Marie Olšinová ◽  
Piotr Jurkiewicz ◽  
Jan Sýkora ◽  
Ján Sabó ◽  
Martin Hof ◽  
...  
Keyword(s):  
Rough Surface ◽  
Lipid Membrane ◽  
Cholesterol Content ◽  
Membrane Dynamics ◽  
Membrane Properties ◽  
Helical Structures ◽  
Transmembrane Peptides ◽  
Acyl Chains ◽  
Dynamics Simulations ◽  
And Function

Transmembrane domains integrate proteins into cellular membranes and support their function. The capacity of these prevalently a-helical structures in mammals to influence membrane properties is poorly understood. Combining experiments with molecular dynamics simulations, we provide evidence that helical transmembrane peptides with their rough surface reduce lateral mobility of membrane constituents. The molecular mechanism involves trapping of lipid acyl chains on the rough surface and segregation of cholesterol from the vicinity of peptides. The observations are supported by our toy model indicating strong effect of rough objects on membrane dynamics. Herein described effect has implications for the organization and function of biological membranes, especially the plasma membrane with high cholesterol content.

Surface Plasmon Resonance Spectroscopic Study on Pore-Forming Behavior of Streptolysin O on Supported Phospholipid Bilayers

2003 ◽  
Vol 774 ◽  
Author(s):  
Thomas Wilkop ◽  
Danke Xu ◽  
Quan Cheng
Keyword(s):  
Surface Plasmon Resonance ◽  
Surface Plasmon ◽  
Plasmon Resonance ◽  
Lipid Membrane ◽  
Bilayer Membrane ◽  
Membrane Properties ◽  
Toxin Binding ◽  
Streptolysin O ◽  
Spacer Layer ◽  
Biomimetic Membrane

AbstractA novel supported bilayer membrane was formed on top of a hydrophobic spacer layer of hexyl thioctate (HT) and its application in the detection of pore forming toxins was demonstrated. The formation kinetics, effect of different flow rates on the fusion process of vesicles and perforation by incubation with streptolysin O (SLO) and pristine membranes were investigated. Individual layers of the multilayer structure were successfully characterized with surface plasmon resonance (SPR), and the resulting spectra were analyzed in order to determine the layer thickness and other membrane properties. The interaction of SLO with the pristine biomimetic membrane resulted in a pronounced change in the reflectivity spectrum. Elements of these spectral changes were analyzed to explain the process of toxin binding and pore formation taking place on the lipid membrane.

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