scholarly journals Exploiting lipopolysaccharide-induced deformation of lipid bilayers to modify membrane composition and generate two-dimensional geometric membrane array patterns

2015 ◽  
Vol 5 (1) ◽  
Author(s):  
Peter G. Adams ◽  
Kirstie L. Swingle ◽  
Walter F. Paxton ◽  
John J. Nogan ◽  
Loreen R. Stromberg ◽  
...  
Keyword(s):  
Lipid Bilayers ◽  
Two Dimensional ◽  
Membrane Composition ◽  
Modify Membrane ◽  
Membrane Array

Endothelial immunogenicity – A matter of matrix microarchitecture

2007 ◽  
Vol 98 (08) ◽  
pp. 278-282 ◽  
Author(s):  
Shmuel Hess ◽  
Elazer Edelman ◽  
Heiko Methe
Keyword(s):  
T Regulatory Cells ◽  
Inflammatory Diseases ◽  
Three Dimensional ◽  
Vascular Diseases ◽  
Matrix Composition ◽  
Two Dimensional ◽  
Membrane Composition ◽  
State Matrix ◽  
Selective Permeability ◽  
Cytokine Stimulation

SummaryThe endothelium is a highly specialized active interface between blood and the underlying tissues, maintaining vascular tone, thrombo-resistance and selective permeability to cells and proteins. It is also an important regulator of inflammatory diseases, and endothelial-leukocyte interactions often herald complex diseases with an inflammatory component.Yet, the exact mechanisms promoting immune activation of endothelial cells (EC) are incompletely understood. Knowledge is accumulating that the immediate environment defines the cellular phenotype, whereby matrix composition and spatial formation (three- versus two-dimensional) seem to act as pivotal mediators. Here we summarize current findings denoting a key role of matrix environment in regulating endothelial immunogenicity. The immune response to three-dimensional matrix-embedded EC stands in stark contrast to the response engendered by injection of these same cells in their free state. Matrix-embedding confers a quiescent endothelial state with reduced expression levels of chemokines, adhesion, costimulatory, and major histocompatibility complex II molecules. Compared to EC grown on two-dimensional tissue culture plates, cytokine-stimulation of matrixembedded EC results in significantly reduced adhesion of natural killer cells and proliferation of co-cultivated allogeneicT cells. On the contrary, matrix-embedded EC induce an immune-inhibitory phenotype of dendritic cells and T regulatory cells to a greater extent than non-embedded EC. As vascular diseases are associated with profound changes in basement membrane composition and overall tissue architecture, our results indicate that the immediate environment of EC might play a pivotal role in initiating and regulating of different vascular diseases. Cell-matrix interconnections appear to govern endothelial immunogenicity and interactions between EC and immune cells.

Molecular and global structure and dynamics of membranes and lipid bilayers

1990 ◽  
Vol 68 (9) ◽  
pp. 999-1012 ◽  
Author(s):  
E. Sackmann
Keyword(s):  
Lipid Bilayers ◽  
Plasma Membranes ◽  
Mechanical Stability ◽  
Dynamic Properties ◽  
Composite Membranes ◽  
Two Dimensional ◽  
Molecular Architecture ◽  
Present Contribution ◽  
Cell Plasma ◽  
Low Dimensionality

The cell plasma is a composite type of material that is made up of a two-dimensional liquid crystal (lipid–protein bilayer) to which a macromolecular network (the cytoskeleton) is loosely coupled. The latter may be approximately two dimensional as in the case of the erythrocytes or may extend throughout the whole cell cytoplasm. Owing to this combination of two states of matter, the membrane combines the dynamics and flexibility of a fluid with the mechanical stability of a solid. Owing to its low dimensionality, the local structure of the bilayer or the global shape of cells may be most effectively controlled and modulated by biochemical signals such as macromolecular adsorption. The present contribution deals with comparative studies of the local and global dynamic properties of biological and artificial membranes. In the first part the question of the physical basis of selective lipid–protein interaction mechanisms is addressed and the outstanding viscoelastic properties of plasma membranes and their role for local instabilities shape fluctuations of cells and the cell–substrate interaction are described. The second part deals with the molecular architecture and dynamics of composite membranes prepared by combining monomeric and macromolecular lipids. These model membranes open new possibilities to mimick complex mechanical processes of cell plasma membranes and to prepare low-dimensionality macromolecular solutions and gels. Finally, the use of such compound systems by nature to prepare the semipermeable protective layers of plant leaves, the so-called cuticle, is discussed. In analogy to plasma membranes, the local transport properties are modulated by variation of the liquid-crystalline state of the monomeric waxes.

scholarly journals Peptide-presenting two-dimensional protein matrix on supported lipid bilayers: An efficient platform for cell adhesion

2007 ◽  
Vol 2 (4) ◽  
pp. 165-172 ◽  
Author(s):  
Rémi Bérat ◽  
Murielle Rémy-Zolghadry ◽  
Céline Gounou ◽  
Claude Manigand ◽  
Sisareuth Tan ◽  
...  
Keyword(s):  
Cell Adhesion ◽  
Lipid Bilayers ◽  
Supported Lipid Bilayers ◽  
Two Dimensional ◽  
Protein Matrix

scholarly journals On the Kinetics of Adsorption and Two-Dimensional Self-Assembly of Annexin A5 on Supported Lipid Bilayers

2005 ◽  
Vol 89 (5) ◽  
pp. 3372-3385 ◽  
Author(s):  
Ralf P. Richter ◽  
Joséphine Lai Kee Him ◽  
Béatrice Tessier ◽  
Céline Tessier ◽  
Alain R. Brisson
Keyword(s):  
Lipid Bilayers ◽  
Self Assembly ◽  
Supported Lipid Bilayers ◽  
Annexin A5 ◽  
Two Dimensional ◽  
Kinetics Of Adsorption ◽  
Kinetics Of

scholarly journals Structural characterization of the antimicrobial peptides myxinidin and WMR in bacterial membrane mimetic micelles and bicelles

2021 ◽  
Author(s):  
Yevhen K. Cherniavskyi ◽  
Rosario Oliva ◽  
Marco Stellato ◽  
Pompea Del Vecchio ◽  
Stefania Galdiero ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Antimicrobial Peptides ◽  
Molecular Dynamics Simulations ◽  
Lipid Bilayers ◽  
Structural Characterization ◽  
Bacterial Membrane ◽  
Membrane Composition ◽  
Membrane Mimetic ◽  
Dynamics Simulations

Antimicrobial peptides are a promising class of alternative antibiotics that interact selectively with negatively charged lipid bilayers. This paper presents the structural characterization of the antimicrobial peptides myxinidin and WMR associated with bacterial membrane mimetic micelles and bicelles by NMR, CD spectroscopy, and Molecular Dynamics simulations. Both peptides adopt a different conformation in the lipidic environment than in aqueous solution. The location of peptides in micelles and bicelles has been studied by paramagnetic relaxation enhancement experiments with paramagnetic tagged 5- and 16-doxyl stearic acid (5-/16-SASL). Multi-microsecond long molecular dynamics simulations of multiple copies of the peptides were used to gain an atomic level of detail on membrane-peptide and peptide-peptide interactions. Our results highlight an essential role of the negatively charged membrane mimetic in the structural stability of both myxinidin and WMR. The peptides localize predominantly in the membrane's headgroup region and have a noticeable membrane thinning effect on the overall bilayer structure. Myxinidin and WMR show different tendency to self-aggregate, which is also influenced by the membrane composition (DOPE/DOPG versus DOPE/DOPG/CL) and can be related to the previously observed difference in the ability of the peptides to disrupt different types of model membranes.

Giant Vesicles and Their Use in Assays for Assessing Membrane Phase State, Curvature, Mechanics, and Electrical Properties

2019 ◽  
Vol 48 (1) ◽  
pp. 93-119 ◽  
Author(s):  
Rumiana Dimova
Keyword(s):  
Electrical Properties ◽  
Lipid Bilayers ◽  
Material Properties ◽  
Phase State ◽  
External Factors ◽  
Membrane Composition ◽  
Membrane Phase ◽  
Membrane Systems ◽  
Giant Vesicles ◽  
Vesicle Preparation

Giant unilamellar vesicles represent a promising and extremely useful model biomembrane system for systematic measurements of mechanical, thermodynamic, electrical, and rheological properties of lipid bilayers as a function of membrane composition, surrounding media, and temperature. The most important advantage of giant vesicles over other model membrane systems is that the membrane responses to external factors such as ions, (macro)molecules, hydrodynamic flows, or electromagnetic fields can be directly observed under the microscope. Here, we briefly review approaches for giant vesicle preparation and describe several assays used for deducing the membrane phase state and measuring a number of material properties, with further emphasis on membrane reshaping and curvature.

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