scholarly journals Integrin-Functionalised Giant Unilamellar Vesicles via Gel-Assisted Formation: Good Practices and Pitfalls

2021 ◽  
Vol 22 (12) ◽  
pp. 6335
Author(s):  
Mariem Souissi ◽  
Julien Pernier ◽  
Olivier Rossier ◽  
Gregory Giannone ◽  
Christophe Le Clainche ◽  
...  
Keyword(s):  
Cell Adhesion ◽  
Cell Membrane ◽  
Transmembrane Protein ◽  
Model Membranes ◽  
Giant Unilamellar Vesicles ◽  
Unilamellar Vesicles ◽  
Good Practices ◽  
Adhesion Proteins ◽  
Controlled Conditions

Giant unilamellar vesicles (GUV) are powerful tools to explore physics and biochemistry of the cell membrane in controlled conditions. For example, GUVs were extensively used to probe cell adhesion, but often using non-physiological linkers, due to the difficulty of incorporating transmembrane adhesion proteins into model membranes. Here we describe a new protocol for making GUVs incorporating the transmembrane protein integrin using gel-assisted swelling. We report an optimised protocol, enumerating the pitfalls encountered and precautions to be taken to maintain the robustness of the protocol. We characterise intermediate steps of small proteoliposome formation and the final formed GUVs. We show that the integrin molecules are successfully incorporated and are functional.

scholarly journals Phase-State Dependent Silica Nanoparticle Uptake of Giant Unilamellar Vesicles

2021 ◽  
Author(s):  
Andrej Kamenac ◽  
Manuel Sirch ◽  
Simon Neidinger ◽  
Christoph Westerhausen
Keyword(s):  
Phase Transition ◽  
Structural Phase Transition ◽  
Phase State ◽  
Structural Phase ◽  
Model Membranes ◽  
Global Maximum ◽  
Giant Unilamellar Vesicles ◽  
Nanoparticle Uptake ◽  
Unilamellar Vesicles ◽  
Bending Modulus

Abstract We quantify endocytosis-like nanoparticle uptake of model membranes as a function of temperature and therefore phase state. As model membranes, we use giant unilamellar vesicles consisting of 1,2-dipentadecanoyl-sn-glycero-3-phosphocholine (15:0 PC). Time-series micrographs of the vesicle shrinkage show uptake rates that are a highly non-linear function of temperature. A global maximum appears close to the main structural phase transition at T = Tm + 3 K, and a minor peak at the pretransition T = Tp = 22 °C. The quality of the kinetics linear fits reveals a deviation from the linear trend at the vesicle shrinkage peaks. To further elucidate the origin of the shrinkage peak, we performed force spectroscopy on a supported lipid bilayer. The results indicate a collapse of the adhesion energy at the structural phase transition. Further using literature results on the bending modulus as function of temperature and Helfrich’s model, this allows us to make qualitative conclusions on the membrane tension as function of temperature.

scholarly journals Imaging of photoacoustic-mediated permeabilization of giant unilamellar vesicles (GUVs)

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Diogo A. Pereira ◽  
Alexandre D. Silva ◽  
Patricia A. T. Martins ◽  
Ana P. Piedade ◽  
Dmitro Martynowych ◽  
...  
Keyword(s):  
Cell Membrane ◽  
Phospholipid Bilayer ◽  
Half Cycle ◽  
Interferometric Imaging ◽  
Giant Unilamellar Vesicles ◽  
Unilamellar Vesicles ◽  
Drug Delivery Vehicles ◽  
Non Invasive ◽  
Foreign Materials ◽  
Peak Pressures

AbstractTarget delivery of large foreign materials to cells requires transient permeabilization of the cell membrane without toxicity. Giant unilamellar vesicles (GUVs) mimic the phospholipid bilayer of the cell membrane and are also useful drug delivery vehicles. Controlled increase of the permeability of GUVs is a delicate balance between sufficient perturbation for the delivery of the GUV contents and damage to the vesicles. Here we show that photoacoustic waves can promote the release of FITC-dextran or GFP from GUVs without damage. Real-time interferometric imaging offers the first movies of photoacoustic wave propagation and interaction with GUVs. The photoacoustic waves are seen as mostly compressive half-cycle pulses with peak pressures of ~ 1 MPa and spatial extent FWHM ~ 36 µm. At a repetition rate of 10 Hz, they enable the release of 25% of the FITC-dextran content of GUVs in 15 min. Such photoacoustic waves may enable non-invasive targeted release of GUVs and cell transfection over large volumes of tissues in just a few minutes.

scholarly journals Effect of the Membrane Composition of Giant Unilamellar Vesicles on Their Budding Probability: A Trade-Off between Elasticity and Preferred Area Difference

Life ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 634
Author(s):  
Ylenia Miele ◽  
Gábor Holló ◽  
István Lagzi ◽  
Federico Rossi
Keyword(s):  
Phospholipid Fatty Acid ◽  
Enzymatic Reaction ◽  
Stimuli Responsive ◽  
Membrane Composition ◽  
Giant Unilamellar Vesicles ◽  
Physical Processes ◽  
Unilamellar Vesicles ◽  
Division Process ◽  
The Origin Of Life ◽  
Area Difference

The budding and division of artificial cells engineered from vesicles and droplets have gained much attention in the past few decades due to an increased interest in designing stimuli-responsive synthetic systems. Proper control of the division process is one of the main challenges in the field of synthetic biology and, especially in the context of the origin of life studies, it would be helpful to look for the simplest chemical and physical processes likely at play in prebiotic conditions. Here we show that pH-sensitive giant unilamellar vesicles composed of mixed phospholipid/fatty acid membranes undergo a budding process, internally fuelled by the urea–urease enzymatic reaction, only for a given range of the membrane composition. A gentle interplay between the effects of the membrane composition on the elasticity and the preferred area difference of the bilayer is responsible for the existence of a narrow range of membrane composition yielding a high probability for budding of the vesicles.

Domain Sorting in Giant Unilamellar Vesicles Adsorbed on Glass

Langmuir ◽  
2021 ◽  
Vol 37 (3) ◽  
pp. 1082-1088
Author(s):  
Chiho Kataoka-Hamai ◽  
Kohsaku Kawakami
Keyword(s):  
Giant Unilamellar Vesicles ◽  
Unilamellar Vesicles

scholarly journals Production of giant unilamellar vesicles and encapsulation of lyotropic nematic liquid crystals

Soft Matter ◽  
2021 ◽  
Author(s):  
Peng Bao ◽  
Daniel A. Paterson ◽  
Sally A. Peyman ◽  
J. Cliff Jones ◽  
Jonathan A. T. Sandoe ◽  
...  
Keyword(s):  
Liquid Crystals ◽  
Nematic Liquid Crystals ◽  
Double Emulsion ◽  
Lyotropic Liquid Crystals ◽  
Giant Unilamellar Vesicles ◽  
Unilamellar Vesicles ◽  
Emulsion Droplets ◽  
Double Emulsion Droplets

We describe a modified microfluidic method for making Giant Unilamellar Vesicles (GUVs) via water/octanol-lipid/water double emulsion droplets and encapsulation of nematic lyotropic liquid crystals (LNLCs).

scholarly journals Cell surface anchorage and ligand-binding domains of the Saccharomyces cerevisiae cell adhesion protein alpha-agglutinin, a member of the immunoglobulin superfamily.

1993 ◽  
Vol 13 (4) ◽  
pp. 2554-2563 ◽  
Author(s):  
D Wojciechowicz ◽  
C F Lu ◽  
J Kurjan ◽  
P N Lipke
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cell Adhesion ◽  
Amino Acid ◽  
Cell Surface ◽  
Consensus Sequence ◽  
Binding Domain ◽  
Immunoglobulin Superfamily ◽  
Cell Contact ◽  
Amino Acid Residues ◽  
Adhesion Proteins

alpha-Agglutinin is a cell adhesion glycoprotein expressed on the cell wall of Saccharomyces cerevisiae alpha cells. Binding of alpha-agglutinin to its ligand a-agglutinin, expressed by a cells, mediates cell-cell contact during mating. Analysis of truncations of the 650-amino-acid alpha-agglutinin structural gene AG alpha 1 delineated functional domains of alpha-agglutinin. Removal of the C-terminal hydrophobic sequence allowed efficient secretion of the protein and loss of cell surface attachment. This cell surface anchorage domain was necessary for linkage to a glycosyl phosphatidylinositol anchor. A construct expressing the N-terminal 350 amino acid residues retained full a-agglutinin-binding activity, localizing the binding domain to the N-terminal portion of alpha-agglutinin. A 278-residue N-terminal peptide was inactive; therefore, the binding domain includes residues between 278 and 350. The segment of alpha-agglutinin between amino acid residues 217 and 308 showed significant structural and sequence similarity to a consensus sequence for immunoglobulin superfamily variable-type domains. The similarity of the alpha-agglutinin-binding domain to mammalian cell adhesion proteins suggests that this structure is a highly conserved feature of adhesion proteins in diverse eukaryotes.

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