Single Giant Unilamellar Vesicle Method Reveals Effect of Antimicrobial Peptide, Magainin 2, and Antibacterial Substance, Tea Catechin, on Membrane Permeability and Membrane Structure

2006 ◽  
Author(s):  
Yukihiro Tamba ◽  
Takuya Yoshitani ◽  
Masahito Yamazaki
Keyword(s):  
Antimicrobial Peptide ◽  
Membrane Permeability ◽  
Membrane Structure ◽  
Giant Unilamellar Vesicle ◽  
Antibacterial Substance

scholarly journals Flavonoids modulate liposomal membrane structure, regulate mitochondrial membrane permeability and prevent erythrocyte oxidative damage

2020 ◽  
Vol 1862 (11) ◽  
pp. 183442 ◽  
Author(s):  
Artem G. Veiko ◽  
Szymon Sekowski ◽  
Elena A. Lapshina ◽  
Agnieszka Z. Wilczewska ◽  
Karolina H. Markiewicz ◽  
...  
Keyword(s):  
Oxidative Damage ◽  
Membrane Permeability ◽  
Mitochondrial Membrane ◽  
Membrane Structure ◽  
Liposomal Membrane ◽  
Mitochondrial Membrane Permeability

scholarly journals Effects of Antibacterial Peptide F1 on Bacterial Liposome Membrane Integrity

2021 ◽  
Vol 8 ◽  
Author(s):  
Qun Wang ◽  
Bo Peng ◽  
Mingyue Song ◽  
Abdullah ◽  
Jun Li ◽  
...  
Keyword(s):  
Antimicrobial Peptide ◽  
Membrane Structure ◽  
Bacterial Membrane ◽  
Phospholipid Membranes ◽  
Phospholipid Membrane ◽  
Gram Positive ◽  
Liposome Membrane ◽  
Gram Negative ◽  
Bacterial Membranes ◽  
Gram Positive Bacteria

Previous studies from our lab have shown that the antimicrobial peptide F1 obtained from the milk fermentation by Lactobacillus paracasei FX-6 derived from Tibetan kefir was different from common antimicrobial peptides; specifically, F1 simultaneously inhibited the growth of Gram-negative and Gram-positive bacteria. Here, we present follow-on work demonstrating that after the antimicrobial peptide F1 acts on either Escherichia coli ATCC 25922 (E. coli) or Staphylococcus aureus ATCC 63589 (S. aureus), their respective bacterial membranes were severely deformed. This deformation allowed leakage of potassium and magnesium ions from the bacterial membrane. The interaction between the antimicrobial peptide F1 and the bacterial membrane was further explored by artificially simulating the bacterial phospholipid membranes and then extracting them. The study results indicated that after the antimicrobial peptide F1 interacted with the bacterial membranes caused significant calcein leakage that had been simulated by different liposomes. Furthermore, transmission electron microscopy observations revealed that the phospholipid membrane structure was destroyed and the liposomes presented aggregation and precipitation. Quartz Crystal Microbalance with Dissipation (QCM-D) results showed that the antimicrobial peptide F1 significantly reduced the quality of liposome membrane and increased their viscoelasticity. Based on the study's findings, the phospholipid membrane particle size was significantly increased, indicating that the antimicrobial peptide F1 had a direct effect on the phospholipid membrane. Conclusively, the antimicrobial peptide F1 destroyed the membrane structure of both Gram-negative and Gram-positive bacteria by destroying the shared components of their respective phospholipid membranes which resulted in leakage of cell contents and subsequently cell death.

scholarly journals Exogenous fatty acids alter phospholipid composition, membrane permeability, capacity for biofilm formation, and antimicrobial peptide susceptibility in Klebsiella pneumoniae

2018 ◽  
Vol 8 (2) ◽  
pp. e00635 ◽  
Author(s):  
Chelsea R. Hobby ◽  
Joshua L. Herndon ◽  
Colton A. Morrow ◽  
Rachel E. Peters ◽  
Steven J. K. Symes ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Klebsiella Pneumoniae ◽  
Antimicrobial Peptide ◽  
Membrane Permeability ◽  
Biofilm Formation ◽  
Phospholipid Composition

scholarly journals Effects of the antimicrobial peptide temporin L on cell morphology, membrane permeability and viability of Escherichia coli

2004 ◽  
Vol 380 (3) ◽  
pp. 859-865 ◽  
Author(s):  
Maria Luisa MANGONI ◽  
Niv PAPO ◽  
Donatella BARRA ◽  
Maurizio SIMMACO ◽  
Argante BOZZI ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Escherichia Coli ◽  
Antimicrobial Peptides ◽  
Antimicrobial Peptide ◽  
Membrane Permeability ◽  
Dependent Manner ◽  
Inner Membrane ◽  
Tetrazolium Chloride ◽  
Bacterial Membranes ◽  
Microbial Invasion

Antimicrobial peptides are produced by all organisms in response to microbial invasion and are considered as promising candidates for future antibiotics. There is a wealth of evidence that many of them interact and increase the permeability of bacterial membranes as part of their killing mechanism. However, it is not clear whether this is the lethal step. To address this issue, we studied the interaction of the antimicrobial peptide temporin L with Escherichia coli by using fluorescence, confocal and electron microscopy. The peptide previously isolated from skin secretions of the frog Rana temporaria has the sequence FVQWFSKFLGRIL-NH2. With regard to fluorescence microscopy, we applied, for the first time, a triple-staining method based on the fluorochromes 5-cyano-2,3-ditolyl tetrazolium chloride, 4´,6-diamidino-2-phenylindole and FITC. This technique enabled us to identify, in the same sample, both living and total cells, as well as bacteria with altered membrane permeability. These results reveal that temporin L increases the permeability of the bacterial inner membrane in a dose-dependent manner without destroying the cell's integrity. At low peptide concentrations, the inner membrane becomes permeable to small molecules but does not allow the killing of bacteria. However, at high peptide concentrations, larger molecules, but not DNA, leak out, which results in cell death. Very interestingly, in contrast with many antimicrobial peptides, temporin L does not lyse E. coli cells but rather forms ghost-like bacteria, as observed by scanning and transmission electron microscopy. Besides shedding light on the mode of action of temporin L and possibly that of other antimicrobial peptides, the present study demonstrates the advantage of using the triple-fluorescence approach combined with microscopical techniques to explore the mechanism of membrane-active peptides in general.

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