scholarly journals Analyzing membrane remodeling and fission using supported bilayers with excess membrane reservoir

2013 ◽  
Vol 8 (1) ◽  
pp. 213-222 ◽  
Author(s):  
Sylvia Neumann ◽  
Thomas J Pucadyil ◽  
Sandra L Schmid
Keyword(s):  
Membrane Remodeling ◽  
Supported Bilayers ◽  
Membrane Reservoir

Self-Assembled Fluid Phase Floating Membranes with Tuneable Water Interlayers

2019 ◽  
Author(s):  
Luke Clifton ◽  
Nicoló Paracini ◽  
Arwel V. Hughes ◽  
Jeremy H. Lakey ◽  
Nina-Juliane Seinke ◽  
...  
Keyword(s):  
Fluid Phase ◽  
Interlayer Thickness ◽  
Supported Bilayers ◽  
Self Assembled Monolayer ◽  
High Coverage ◽  
Nano Technology ◽  
Surface Distance ◽  
Potential Applications ◽  
Self Assembled ◽  
Coated Surfaces

<p>We present a reliable method for the fabrication of fluid phase unsaturated bilayers which are readily self-assembled on charged self-assembled monolayer (SAM) surfaces producing high coverage floating supported bilayers where the membrane to surface distance could be controlled with nanometer precision. Vesicle fusion was used to deposit the bilayers onto anionic SAM coated surfaces. Upon assembly the bilayer to SAM solution interlayer thickness was 7-10 Å with evidence suggesting that this layer was present due to SAM hydration repulsion of the bilayer from the surface. This distance could be increased using low concentrations of salts which caused the interlayer thickness to enlarge to ~33 Å. Reducing the salt concentration resulted in a return to a shorter bilayer to surface distance. These accessible and controllable membrane models are well suited to a range of potential applications in biophysical studies, bio-sensors and Nano-technology.</p><br>

scholarly journals Biomechanics of Neutrophil Tethers

Life ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 515
Author(s):  
Andrea Cugno ◽  
Alex Marki ◽  
Klaus Ley
Keyword(s):  
Cell Activation ◽  
Optical Trap ◽  
Biomechanical Properties ◽  
Force Microscopy ◽  
Advantages And Disadvantages ◽  
Atomic Force ◽  
Microfluidic Flow ◽  
Biomembrane Force Probe ◽  
Membrane Reservoir

Leukocytes, including neutrophils, which are propelled by blood flow, can roll on inflamed endothelium using transient bonds between selectins and their ligands, and integrins and their ligands. When such receptor–ligand bonds last long enough, the leukocyte microvilli become extended and eventually form thin, 20 m long tethers. Tether formation can be observed in blood vessels in vivo and in microfluidic flow chambers. Tethers can also be extracted using micropipette aspiration, biomembrane force probe, optical trap, or atomic force microscopy approaches. Here, we review the biomechanical properties of leukocyte tethers as gleaned from such measurements and discuss the advantages and disadvantages of each approach. We also review and discuss viscoelastic models that describe the dependence of tether formation on time, force, rate of loading, and cell activation. We close by emphasizing the need to combine experimental observations with quantitative models and computer simulations to understand how tether formation is affected by membrane tension, membrane reservoir, and interactions of the membrane with the cytoskeleton.

scholarly journals Correlative AFM and fluorescence imaging demonstrate nanoscale membrane remodeling and ring-like and tubular structure formation by septins

Nanoscale ◽  
2021 ◽  
Author(s):  
Anthony Vial ◽  
Cyntia Taveneau ◽  
Luca Costa ◽  
brieuc chauvin ◽  
hussein nasrallah ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Cell Division ◽  
Structure Formation ◽  
Fluorescence Imaging ◽  
Tubular Structure ◽  
Membrane Remodeling

Septins are ubiquitous cytoskeletal filaments that interact with the inner plasma membrane and are essential for cell division in eukaryotes. In cellular contexts, septins are often localized at micrometric gaussian...

scholarly journals Membrane fusion studied by colloidal probes

2021 ◽  
Vol 50 (2) ◽  
pp. 223-237 ◽  
Author(s):  
Hannes Witt ◽  
Filip Savić ◽  
Sarah Verbeek ◽  
Jörn Dietz ◽  
Gesa Tarantola ◽  
...  
Keyword(s):  
Membrane Fusion ◽  
Optical Tweezers ◽  
Three Dimensional ◽  
Biological Processes ◽  
Supported Membranes ◽  
Supported Bilayers ◽  
Force Microscopy ◽  
Advantages And Disadvantages ◽  
Atomic Force ◽  
Colloidal Probes

AbstractMembrane-coated colloidal probes combine the benefits of solid-supported membranes with a more complex three-dimensional geometry. This combination makes them a powerful model system that enables the visualization of dynamic biological processes with high throughput and minimal reliance on fluorescent labels. Here, we want to review recent applications of colloidal probes for the study of membrane fusion. After discussing the advantages and disadvantages of some classical vesicle-based fusion assays, we introduce an assay using optical detection of fusion between membrane-coated glass microspheres in a quasi two-dimensional assembly. Then, we discuss free energy considerations of membrane fusion between supported bilayers, and show how colloidal probes can be combined with atomic force microscopy or optical tweezers to access the fusion process with even greater detail.

scholarly journals Investigating the Disordered and Membrane-Active Peptide A-Cage-C Using Conformational Ensembles

Molecules ◽  
2021 ◽  
Vol 26 (12) ◽  
pp. 3607
Author(s):  
Olena Dobrovolska ◽  
Øyvind Strømland ◽  
Ørjan Sele Handegård ◽  
Martin Jakubec ◽  
Morten L. Govasli ◽  
...  
Keyword(s):  
Conformational Changes ◽  
Protein Misfolding ◽  
Driving Forces ◽  
Conformational Space ◽  
Supported Bilayers ◽  
Conformational Ensembles ◽  
Protein Membrane ◽  
Chimeric Polypeptide ◽  
Protein Misfolding And Aggregation ◽  
In Silico Analyses

The driving forces and conformational pathways leading to amphitropic protein-membrane binding and in some cases also to protein misfolding and aggregation is the subject of intensive research. In this study, a chimeric polypeptide, A-Cage-C, derived from α-Lactalbumin is investigated with the aim of elucidating conformational changes promoting interaction with bilayers. From previous studies, it is known that A-Cage-C causes membrane leakages associated with the sporadic formation of amorphous aggregates on solid-supported bilayers. Here we express and purify double-labelled A-Cage-C and prepare partially deuterated bicelles as a membrane mimicking system. We investigate A-Cage-C in the presence and absence of these bicelles at non-binding (pH 7.0) and binding (pH 4.5) conditions. Using in silico analyses, NMR, conformational clustering, and Molecular Dynamics, we provide tentative insights into the conformations of bound and unbound A-Cage-C. The conformation of each state is dynamic and samples a large amount of overlapping conformational space. We identify one of the clusters as likely representing the binding conformation and conclude tentatively that the unfolding around the central W23 segment and its reorientation may be necessary for full intercalation at binding conditions (pH 4.5). We also see evidence for an overall elongation of A-Cage-C in the presence of model bilayers.

scholarly journals The role of VPS4 in ESCRT-III polymer remodeling

2019 ◽  
Vol 47 (1) ◽  
pp. 441-448 ◽  
Author(s):  
Christophe Caillat ◽  
Sourav Maity ◽  
Nolwenn Miguet ◽  
Wouter H. Roos ◽  
Winfried Weissenhorn
Keyword(s):  
Active Role ◽  
Mechanistic Models ◽  
Membrane Remodeling ◽  
Filament Formation ◽  
Enveloped Viruses ◽  
Endosomal Sorting ◽  
Membrane Fission ◽  
Dynamic Assembly ◽  
Inside Out

Abstract The endosomal sorting complex required for transport-III (ESCRT-III) and VPS4 catalyze a variety of membrane-remodeling processes in eukaryotes and archaea. Common to these processes is the dynamic recruitment of ESCRT-III proteins from the cytosol to the inner face of a membrane neck structure, their activation and filament formation inside or at the membrane neck and the subsequent or concomitant recruitment of the AAA-type ATPase VPS4. The dynamic assembly of ESCRT-III filaments and VPS4 on cellular membranes induces constriction of membrane necks with large diameters such as the cytokinetic midbody and necks with small diameters such as those of intraluminal vesicles or enveloped viruses. The two processes seem to use different sets of ESCRT-III filaments. Constriction is then thought to set the stage for membrane fission. Here, we review recent progress in understanding the structural transitions of ESCRT-III proteins required for filament formation, the functional role of VPS4 in dynamic ESCRT-III assembly and its active role in filament constriction. The recent data will be discussed in the context of different mechanistic models for inside-out membrane fission.

scholarly journals Membrane Remodeling as a Key Player of the Hepatotoxicity Induced by Co-Exposure to Benzo[a]pyrene and Ethanol of Obese Zebrafish Larvae

Biomolecules ◽  
2018 ◽  
Vol 8 (2) ◽  
pp. 26 ◽  
Author(s):  
Muhammad Imran ◽  
Odile Sergent ◽  
Arnaud Tête ◽  
Isabelle Gallais ◽  
Martine Chevanne ◽  
...  
Keyword(s):  
Membrane Remodeling ◽  
Zebrafish Larvae
Sign in / Sign up

Export Citation Format

Share Document