scholarly journals Visualization of diffusion limited antimicrobial peptide attack on supported lipid membranes

Soft Matter ◽  
2018 ◽  
Vol 14 (29) ◽  
pp. 6146-6154 ◽  
Author(s):  
George R. Heath ◽  
Patrick L. Harrison ◽  
Peter N. Strong ◽  
Stephen D. Evans ◽  
Keith Miller
Keyword(s):  
Antimicrobial Peptide ◽  
Lipid Bilayers ◽  
Lipid Membranes ◽  
Mechanisms Of Action ◽  
Membrane Disruption ◽  
Diffusion Limited Aggregation ◽  
Diffusion Limited ◽  
Rapid Removal ◽  
Supported Lipid Membranes ◽  
Insight Into

Using fast-scanning AFM to capture an antimicrobial peptide attack on planar lipid bilayers allows us to watch membrane disruption in real time. We observed the rapid removal of membrane in a 2D diffusion limited aggregation process giving new insight into antimicrobial peptide mechanisms of action.

Making lipid membranes even tougher

2007 ◽  
Vol 22 (8) ◽  
pp. 2189-2194 ◽  
Author(s):  
Jognandan Prashar ◽  
Phillip Sharp ◽  
Mathew Scarffe ◽  
Bruce Cornell
Keyword(s):  
Lipid Bilayers ◽  
Lipid Membranes ◽  
Room Temperature ◽  
Materials Science ◽  
Lipid Phase ◽  
Molecular Sensing ◽  
Long Term Storage ◽  
Supported Lipid Membranes ◽  
Term Storage

Biosensors based on lipid membranes promise an inexpensive and versatile platform for application in many fields of molecular sensing. An extensive review of the applications for tethered membranes was reported in the July 2006 MRS Bulletin [A.N. Parikh and J.T. Groves, Materials science of supported lipid membranes. MRS Bull.31(8), 507 (2006)]. The commercial use to which tethered lipid membranes have been applied has been limited by their stability under long-term storage. This report describes a novel membrane construct that is stable at room temperature for months, eliminates the mobile lipid phase present in lipid bilayers, and is robust against detergents under conditions that would destroy a lipid bilayer.

Microcavity-Supported Lipid Membranes: Versatile Platforms for Building Asymmetric Lipid Bilayers and for Protein Recognition

2019 ◽  
Vol 2 (8) ◽  
pp. 3404-3417 ◽  
Author(s):  
Guilherme B. Berselli ◽  
Nirod Kumar Sarangi ◽  
Sivaramakrishnan Ramadurai ◽  
Paul V. Murphy ◽  
Tia E. Keyes
Keyword(s):  
Lipid Bilayers ◽  
Lipid Membranes ◽  
Protein Recognition ◽  
Supported Lipid Membranes

Investigating the Function of Ion Channels in Tethered Lipid Membranes by Impedance Spectroscopy

MRS Bulletin ◽  
2005 ◽  
Vol 30 (3) ◽  
pp. 207-210 ◽  
Author(s):  
Samuel Terrettaz ◽  
Horst Vogel
Keyword(s):  
Ion Channels ◽  
Impedance Spectroscopy ◽  
Ligand Binding ◽  
Lipid Bilayers ◽  
Lipid Membranes ◽  
Gold Electrodes ◽  
Channel Activity ◽  
Electrophysiological Measurements ◽  
Supported Lipid Membranes ◽  
Specific Ligand

AbstractThe function of biologically important ion channels can be measured in supported lipid membranes by impedance spectroscopy. This approach offers substantial advantages over traditional electrophysiological measurements. In this article, we present an overview of the field, with a special emphasis on the reconstitution of ion channels in lipid bilayers tethered to gold electrodes and the modulation of their channel activity by specific ligand binding.

scholarly journals Sticking and sliding of lipid bilayers on deformable substrates

Soft Matter ◽  
2017 ◽  
Vol 13 (1) ◽  
pp. 181-186 ◽  
Author(s):  
L. Stubbington ◽  
M. Arroyo ◽  
M. Staykova
Keyword(s):  
Stress Response ◽  
Lipid Bilayers ◽  
Lipid Membranes ◽  
Supported Lipid Membranes

Supported lipid membranes exhibit two different stress response mechanisms to substrate deformation.

scholarly journals The Mechanisms of Action of Triindolylmethane Derivatives on Lipid Membranes

Acta Naturae ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 38-45 ◽  
Author(s):  
S. S. Efimova ◽  
T. E. Tertychnaya ◽  
S. N. Lavrenov ◽  
O. S. Ostroumova
Keyword(s):  
Lipid Bilayers ◽  
Lipid Membranes ◽  
Antibacterial Agents ◽  
Membrane Lipids ◽  
Mechanisms Of Action ◽  
Electrical Stability ◽  
Membrane Breakdown ◽  
Model Lipid Membranes ◽  
Transmembrane Pores ◽  
The Difference

The effects of new synthetic antibacterial agents - tris(1-pentyl-1H-indol-3-yl)methylium chloride (LCTA-1975) and (1-(4-(dimethylamino)-2,5-dioxo-2,5-dihydro-1H-pyrrol-3-yl)-1H-indol-3-yl)bis(1-propyl- 1H-indol-3-yl)methylium chloride (LCTA-2701 - on model lipid membranes were studied. The ability of the tested agents to form ion-conductive transmembrane pores, influence the electrical stability of lipid bilayers and the phase transition of membrane lipids, and cause the deformation and fusion of lipid vesicles was investigated. It was established that both compounds exert a strong detergent effect on model membranes. The results of differential scanning microcalorimetry and measuring of the threshold transmembrane voltage that caused membrane breakdown before and after adsorption of LCTA-1975 and LCTA-2701 indicated that both agents cause disordering of membrane lipids. Synergism of the uncoupling action of antibiotics and the alkaloid capsaicin on model lipid membranes was shown. The threshold concentration of the antibiotic that caused an increase in the ion permeability of the lipid bilayer depended on the membrane lipid composition. It was lower by an order of magnitude in the case of negatively charged lipid bilayers than for the uncharged membranes. This can be explained by the positive charge of the tested agents. At the same time, LCTA-2701 was characterized by greater efficiency than LCTA-1975. In addition to its detergent action, LCTA-2701 can induce ion-permeable transmembrane pores: step-like current fluctuations corresponding to the opening and closing of individual ion channels were observed. The difference in the mechanisms of action might be related to the structural features of the antibiotic molecules: in the LCTA-1975 molecule, all three substituents at the nitrogen atoms of the indole rings are identical and represent n-alkyl (pentyl) groups, while LCTA-2701 contains a maleimide group, along with two alkyl substituents (n-propyl). The obtained results might be relevant to our understanding of the mechanism of action of new antibacterial agents, explaining the difference in the selectivity of action of the tested agents on the target microorganisms and their toxicity to human cells. Model lipid membranes should be used in further studies of the trends in the modification and improvement of the structures of new antibacterial agents.

Observation of Concanavalin-A receptors on hydrated planar erythrocyte membrane film by in situ electron microscopy

1983 ◽  
Vol 41 ◽  
pp. 608-609
Author(s):  
Neng-Bo He ◽  
S.W. Hui
Keyword(s):  
Lipid Bilayers ◽  
Erythrocyte Membrane ◽  
Lipid Membranes ◽  
Surface Film ◽  
Biological Membranes ◽  
Electron Microscopic Observation ◽  
Electron Microscopic ◽  
Black Lipid Membranes ◽  
Fine Mesh ◽  
Planar Films

Monolayers and planar "black" lipid membranes have been widely used as models for studying the structure and properties of biological membranes. Because of the lack of a suitable method to prepare these membranes for electron microscopic observation, their ultrastructure is so far not well understood. A method of forming molecular bilayers over the holes of fine mesh grids was developed by Hui et al. to study hydrated and unsupported lipid bilayers by electron diffraction, and to image phase separated domains by diffraction contrast. We now adapted the method of Pattus et al. of spreading biological membranes vesicles on the air-water interfaces to reconstitute biological membranes into unsupported planar films for electron microscopic study. hemoglobin-free human erythrocyte membrane stroma was prepared by hemolysis. The membranes were spreaded at 20°C on balanced salt solution in a Langmuir trough until a surface pressure of 20 dyne/cm was reached. The surface film was repeatedly washed by passing to adjacent troughs over shallow partitions (fig. 1).

Simulation Modeling of Supported Lipid Membranes – A Review

2014 ◽  
Vol 14 (5) ◽  
pp. 617-623 ◽  
Author(s):  
Michael Hirtz ◽  
Naresh Kumar ◽  
Lifeng Chi
Keyword(s):  
Lipid Membranes ◽  
Simulation Modeling ◽  
Supported Lipid Membranes

scholarly journals Electrochemical Properties of Lipid Membranes Self-Assembled from Bicelles

Membranes ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 11
Author(s):  
Damian Dziubak ◽  
Kamil Strzelak ◽  
Slawomir Sek
Keyword(s):  
Electrochemical Properties ◽  
Self Assembly ◽  
Lipid Membranes ◽  
Lipid Membrane ◽  
Membrane Resistance ◽  
Electrochemical Characteristics ◽  
Freeze Thaw ◽  
Lipid Films ◽  
Supported Lipid Membranes

Supported lipid membranes are widely used platforms which serve as simplified models of cell membranes. Among numerous methods used for preparation of planar lipid films, self-assembly of bicelles appears to be promising strategy. Therefore, in this paper we have examined the mechanism of formation and the electrochemical properties of lipid films deposited onto thioglucose-modified gold electrodes from bicellar mixtures. It was found that adsorption of the bicelles occurs by replacement of interfacial water and it leads to formation of a double bilayer structure on the electrode surface. The resulting lipid assembly contains numerous defects and pinholes which affect the permeability of the membrane for ions and water. Significant improvement in morphology and electrochemical characteristics is achieved upon freeze–thaw treatment of the deposited membrane. The lipid assembly is rearranged to single bilayer configuration with locally occurring patches of the second bilayer, and the number of pinholes is substantially decreased. Electrochemical characterization of the lipid membrane after freeze–thaw treatment demonstrated that its permeability for ions and water is significantly reduced, which was manifested by the relatively high value of the membrane resistance.

scholarly journals Cardiolipin-Containing Lipid Membranes Attract the Bacterial Cell Division Protein DivIVA

2021 ◽  
Vol 22 (15) ◽  
pp. 8350
Author(s):  
Naďa Labajová ◽  
Natalia Baranova ◽  
Miroslav Jurásek ◽  
Robert Vácha ◽  
Martin Loose ◽  
...  
Keyword(s):  
Cell Division ◽  
Lipid Bilayers ◽  
Bacterial Cell ◽  
Lipid Membranes ◽  
Model Organism ◽  
Active Role ◽  
Membrane Curvature ◽  
Bacterial Cell Division ◽  
Division Site ◽  
Clostridioides Difficile

DivIVA is a protein initially identified as a spatial regulator of cell division in the model organism Bacillus subtilis, but its homologues are present in many other Gram-positive bacteria, including Clostridia species. Besides its role as topological regulator of the Min system during bacterial cell division, DivIVA is involved in chromosome segregation during sporulation, genetic competence, and cell wall synthesis. DivIVA localizes to regions of high membrane curvature, such as the cell poles and cell division site, where it recruits distinct binding partners. Previously, it was suggested that negative curvature sensing is the main mechanism by which DivIVA binds to these specific regions. Here, we show that Clostridioides difficile DivIVA binds preferably to membranes containing negatively charged phospholipids, especially cardiolipin. Strikingly, we observed that upon binding, DivIVA modifies the lipid distribution and induces changes to lipid bilayers containing cardiolipin. Our observations indicate that DivIVA might play a more complex and so far unknown active role during the formation of the cell division septal membrane.

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