scholarly journals Magainin 2 and PGLa in Bacterial Membrane Mimics II: Membrane Fusion and Sponge Phase Formation

2019 ◽  
Author(s):  
Ivo Kabelka ◽  
Michael Pachler ◽  
Sylvain Prévost ◽  
Ilse Letofsky-Papst ◽  
Karl Lohner ◽  
...  
Keyword(s):  
Membrane Fusion ◽  
Phase Formation ◽  
Bacterial Membrane ◽  
Membrane Mimics ◽  
Sponge Phase

scholarly journals Synergism between Magainin 2 and PGLa in Bacterial Membrane Mimics Leads to Membrane Fusion and Sponge Phase Formation

2020 ◽  
Vol 118 (3) ◽  
pp. 343a ◽  
Author(s):  
Ivo Kabelka ◽  
Michael Pachler ◽  
Sylvain Prévost ◽  
Ilse Letofsky-Papst ◽  
Karl Lohner ◽  
...  
Keyword(s):  
Membrane Fusion ◽  
Phase Formation ◽  
Bacterial Membrane ◽  
Membrane Mimics ◽  
Sponge Phase

Interfacial enzyme activation, non-lamellar phase formation and membrane fusion. Is there a conducting thread?

1999 ◽  
Vol 111 ◽  
pp. 55-68 ◽  
Author(s):  
Fe′lix M. Goñi ◽  
Gorka Basáñez ◽  
M Begoña Ruiz-Argüello ◽  
Alicia Alonso
Keyword(s):  
Membrane Fusion ◽  
Phase Formation ◽  
Enzyme Activation ◽  
Lamellar Phase

scholarly journals Biomembrane mimics and their roles in anti-bacterial drug discovery

ADMET & DMPK ◽  
2017 ◽  
Vol 5 (1) ◽  
pp. 9 ◽  
Author(s):  
Xiaohui Hu ◽  
Kin Tam
Keyword(s):  
Drug Discovery ◽  
Antibacterial Therapy ◽  
Antibacterial Drug ◽  
Bacterial Membrane ◽  
Mechanistic Studies ◽  
Membrane Interaction ◽  
Membrane Mimics ◽  
Membrane Mimetic ◽  
Infection Disease ◽  
Pathogenic Microbe

Cell membrane is at the frontline of the battle between pathogenic microbe and host. A thorough understanding of bacterial membrane is fundamental to tackle infection disease. Membrane mimetic provides a powerful tool for mechanistic interrogation of drug-membrane interaction. Herein, we summarized major features of bacterial and mammalian cell in context of antibacterial therapy. Much details were given to model membranes and their application in mechanistic studies. Current challenge in antibacterial therapy and perspective of membrane mimics in antibacterial drug discovery were also provided.

Structural and functional diversity of bacterial membrane fusion proteins

2009 ◽  
Vol 1794 (5) ◽  
pp. 794-807 ◽  
Author(s):  
Helen I. Zgurskaya ◽  
Yoichi Yamada ◽  
Elena B. Tikhonova ◽  
Qiang Ge ◽  
Ganesh Krishnamoorthy
Keyword(s):  
Membrane Fusion ◽  
Functional Diversity ◽  
Fusion Proteins ◽  
Bacterial Membrane ◽  
Membrane Fusion Proteins

scholarly journals Magainin 2 and PGLa in Bacterial Membrane Mimics I: Peptide-Peptide and Lipid-Peptide Interactions

2019 ◽  
Vol 117 (10) ◽  
pp. 1858-1869 ◽  
Author(s):  
Michael Pachler ◽  
Ivo Kabelka ◽  
Marie-Sousai Appavou ◽  
Karl Lohner ◽  
Robert Vácha ◽  
...  
Keyword(s):  
Bacterial Membrane ◽  
Membrane Mimics ◽  
Peptide Interactions

scholarly journals Antimicrobial peptide activity in asymmetric bacterial membrane mimics

2021 ◽  
Author(s):  
Lisa Marx ◽  
Moritz P. K. Frewein ◽  
Enrico Federico Semeraro ◽  
Gerald N Rechberger ◽  
Karl Lohner ◽  
...  
Keyword(s):  
Antimicrobial Peptide ◽  
Lipid Membranes ◽  
Bacterial Membrane ◽  
Membrane Mimics

We report on the response of asymmetric lipid membranes composed of palmitoyl oleoyl phosphatidylethanolamine and palmitoyl oleoyl phosphatidylglycerol to interactions with the frog peptides L18W-PGLa and magainin 2 (MG2a), as...

Trophoblast Cell Membrane Interactions at Implantation

1970 ◽  
Vol 28 ◽  
pp. 310-311
Author(s):  
A. C. Enders
Keyword(s):  
Epithelial Cells ◽  
Cell Membrane ◽  
Membrane Fusion ◽  
Trophoblast Cell ◽  
Membrane Interactions ◽  
Uterine Epithelial Cells ◽  
Functional Complex ◽  
Cytotrophoblast Cells ◽  
Complex Relationships ◽  
Syncytial Trophoblast

The alteration in membrane relationships seen at implantation include 1) interaction between cytotrophoblast cells to form syncytial trophoblast and addition to the syncytium by subsequent fusion of cytotrophoblast cells, 2) formation of a wide variety of functional complex relationships by trophoblast with uterine epithelial cells in the process of invasion of the endometrium, and 3) in the case of the rabbit, fusion of some uterine epithelial cells with the trophoblast.Formation of syncytium is apparently a membrane fusion phenomenon in which rapid confluence of cytoplasm often results in isolation of residual membrane within masses of syncytial trophoblast. Often the last areas of membrane to disappear are those including a desmosome where the cell membranes are apparently held apart from fusion.

Characterization of reactive phase formation in sputter-deposited Ni/Al multilayer thin films using TEM

1996 ◽  
Vol 54 ◽  
pp. 1000-1001
Author(s):  
G. Lucadamo ◽  
K. Barmak ◽  
C. Michaelsen
Keyword(s):  
Thin Films ◽  
Phase Formation ◽  
Dark Field ◽  
Nickel Layer ◽  
Multilayer Thin Films ◽  
Cross Sectional ◽  
Dark Field Imaging ◽  
Transmission Electron ◽  
Sputter Deposited ◽  
Constant Heating

The subject of reactive phase formation in multilayer thin films of varying periodicity has stimulated much research over the past few years. Recent studies have sought to understand the reactions that occur during the annealing of Ni/Al multilayers. Dark field imaging from transmission electron microscopy (TEM) studies in conjunction with in situ x-ray diffraction measurements, and calorimetry experiments (isothermal and constant heating rate), have yielded new insights into the sequence of phases that occur during annealing and the evolution of their microstructure.In this paper we report on reactive phase formation in sputter-deposited lNi:3Al multilayer thin films with a periodicity A (the combined thickness of an aluminum and nickel layer) from 2.5 to 320 nm. A cross-sectional TEM micrograph of an as-deposited film with a periodicity of 10 nm is shown in figure 1. This image shows diffraction contrast from the Ni grains and occasionally from the Al grains in their respective layers.

Lipid Polymorphism and Virus-Membrane Fusion as Observed in Vitrified Thin Films by Cryo-Electron Microscopy

1990 ◽  
Vol 48 (1) ◽  
pp. 492-493
Author(s):  
P.M. Frederik ◽  
K.N.J. Burger ◽  
M.C.A. Stuart ◽  
A.J. Verkleij
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
Membrane Fusion ◽  
Film Formation ◽  
Molar Ratio ◽  
Influenza B ◽  
Complex Structures ◽  
Type Ii ◽  
Suspended Material ◽  
Cryo Electron Microscopy

Cellular membranes are often composed of phospholipid mixtures in which one or more components have a tendency to adopt a type II non-bilayer lipid structure such as the inverted hexagonal (H||) phase. The formation of a type II non-bilayer intermediate, the inverted lipid micel is proposed as the initial step in membrane fusion (Verkleij 1984, Siegel, 1986). In the various forms of cellular transport mediated by carrier vesicles (e.g. exocytosis, endocytosis) the regulation of membrane fusion, and hence of inverted lipid micel formation, is of vital importance.We studied the phase behaviour of simple and complex lipid mixtures by cryo-electron microscopy to gain more insight in the ultrastructure of different lipid phases (e.g. Pβ’, Lα, H||) and in the complex membrane structures arising after Lα < - > H|| phase changes (e.g. isotropic, cubic). To prepare hydrated thin films a 700 mesh hexagonal grid (without supporting film) was dipped into and withdrawn from a liposome suspension. The excess fluid was blotted against filter paper and the thin films that form between the bars of the specimen grid were immediately (within 1 second) vitrified by plunging of the carrier grids into ethane cooled to its melting point by liquid nitrogen (Dubochet et al., 1982). Surface active molecules such as phospholipids play an important role in the formation and thinning of these aqueous thin films (Frederik et al., 1989). The formation of two interfacial layers at the air-water interfaces requires transport of surface molecules from the suspension as well as the orientation of these molecules at the interfaces. During the spontaneous thinning of the film the interfaces approach each other, initially driven by capillary forces later by Van der Waals attraction. The process of thinning results in the sorting by size of the suspended material and is also accompanied by a loss of water from the thinner parts of the film. This loss of water may result in the concentration and eventually in partial dehydration of suspended material even if thin films are vitrified within 1 sec after their formation. Film formation and vitrification were initiated at temperatures between 20-60°C by placing die equipment in an incubator provided widi port holes for the necessary manipulations. Unilamellar vesicles were made from dipalmitoyl phosphatidyl choline (DPPC) by an extrusion method and showed a smooth (Lα) or a rippled (PB’.) structure depending on the temperature of the suspensions and the temperature of film formation (50°C resp. 39°C) prior to vitrification. The thermotropic phases of hydrated phospholipids are thus faithfully preserved in vitrified thin films (fig. a,b). Complex structures arose when mixtures of dioleoylphosphatidylethanol-amine (DOPE), dioleoylphosphatidylcholine (DOPC) and cholesterol (molar ratio 3/1/2) are heated and used for thin film formation. The tendency of DOPE to adopt the H|| phase is responsible for the formation of complex structures in this lipid mixture. Isotropic and cubic areas (fig. c,d) having a bilayer structure are found in coexistence with H|| cylinders (fig. e). The formation of interlamellar attachments (ILA’s) as observed in isotropic and cubic structures is also thought to be of importance in biological fusion events. Therefore the study of the fusion activity of influenza B virus with liposomes (DOPE/DOPC/cholesterol/ganglioside in a molar ratio 1/1/2/0.2) was initiated. At neutral pH only adsorption of virus to liposomes was observed whereas 2 minutes after a drop in pH (7.4 - > 5.4) fusion between virus and liposome membranes was demonstrated (fig. f). The micrographs illustrate the exciting potential of cryo-electron microscopy to study lipid-lipid and lipid-protein interactions in hydrated specimens.

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