scholarly journals Listeriolysin S: A bacteriocin from Listeria monocytogenes that induces membrane permeabilization in a contact-dependent manner

2021 ◽  
Vol 118 (40) ◽  
pp. e2108155118
Author(s):  
Jazmín Meza-Torres ◽  
Mickaël Lelek ◽  
Juan J. Quereda ◽  
Martin Sachse ◽  
Giulia Manina ◽  
...  
Keyword(s):  
Listeria Monocytogenes ◽  
Cell Membrane ◽  
Single Molecule ◽  
Bactericidal Activity ◽  
Bacterial Cell ◽  
Atp Release ◽  
Inhibition Mechanism ◽  
Dependent Manner ◽  
Bacterial Membranes ◽  
Bacterial Cell Membrane

Listeriolysin S (LLS) is a thiazole/oxazole–modified microcin (TOMM) produced by hypervirulent clones of Listeria monocytogenes. LLS targets specific gram-positive bacteria and modulates the host intestinal microbiota composition. To characterize the mechanism of LLS transfer to target bacteria and its bactericidal function, we first investigated its subcellular distribution in LLS-producer bacteria. Using subcellular fractionation assays, transmission electron microscopy, and single-molecule superresolution microscopy, we identified that LLS remains associated with the bacterial cell membrane and cytoplasm and is not secreted to the bacterial extracellular space. Only living LLS-producer bacteria (and not purified LLS-positive bacterial membranes) display bactericidal activity. Applying transwell coculture systems and microfluidic-coupled microscopy, we determined that LLS requires direct contact between LLS-producer and -target bacteria in order to display bactericidal activity, and thus behaves as a contact-dependent bacteriocin. Contact-dependent exposure to LLS leads to permeabilization/depolarization of the target bacterial cell membrane and adenosine triphosphate (ATP) release. Additionally, we show that lipoteichoic acids (LTAs) can interact with LLS and that LTA decorations influence bacterial susceptibility to LLS. Overall, our results suggest that LLS is a TOMM that displays a contact-dependent inhibition mechanism.

scholarly journals Telavancin, a Multifunctional Lipoglycopeptide, Disrupts both Cell Wall Synthesis and Cell Membrane Integrity in Methicillin-Resistant Staphylococcus aureus

2005 ◽  
Vol 49 (3) ◽  
pp. 1127-1134 ◽  
Author(s):  
Deborah L. Higgins ◽  
Ray Chang ◽  
Dmitri V. Debabov ◽  
Joey Leung ◽  
Terry Wu ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Cell Wall ◽  
Membrane Potential ◽  
Cell Membrane ◽  
Bactericidal Activity ◽  
Bacterial Cell ◽  
Cell Membrane Potential ◽  
Gram Positive ◽  
Methicillin Resistant ◽  
Bacterial Cell Membrane

ABSTRACTThe emergence and spread of multidrug-resistant gram-positive bacteria represent a serious clinical problem. Telavancin is a novel lipoglycopeptide antibiotic that possesses rapid in vitro bactericidal activity against a broad spectrum of clinically relevant gram-positive pathogens. Here we demonstrate that telavancin's antibacterial activity derives from at least two mechanisms. As observed with vancomycin, telavancin inhibited late-stage peptidoglycan biosynthesis in a substrate-dependent fashion and bound the cell wall, as it did the lipid II surrogate tripeptideN,N′-diacetyl-l-lysinyl-d-alanyl-d-alanine, with high affinity. Telavancin also perturbed bacterial cell membrane potential and permeability. In methicillin-resistantStaphylococcus aureus, telavancin caused rapid, concentration-dependent depolarization of the plasma membrane, increases in permeability, and leakage of cellular ATP and K+. The timing of these changes correlated with rapid , concentration-dependent loss of bacterial viability, suggesting that the early bactericidal activity of telavancin results from dissipation of cell membrane potential and an increase in membrane permeability. Binding and cell fractionation studies provided direct evidence for an interaction of telavancin with the bacterial cell membrane; stronger binding interactions were observed with the bacterial cell wall and cell membrane relative to vancomycin. We suggest that this multifunctional mechanism of action confers advantageous antibacterial properties.

Lupinifolin from Derris reticulata possesses bactericidal activity on Staphylococcus aureus by disrupting bacterial cell membrane

2016 ◽  
Vol 71 (2) ◽  
pp. 357-366 ◽  
Author(s):  
Kamol Yusook ◽  
Oratai Weeranantanapan ◽  
Yanling Hua ◽  
Pakarang Kumkrai ◽  
Nuannoi Chudapongse
Keyword(s):  
Staphylococcus Aureus ◽  
Cell Membrane ◽  
Bactericidal Activity ◽  
Bacterial Cell ◽  
Bacterial Cell Membrane ◽  
Derris Reticulata

scholarly journals Acylation of SC4 dodecapeptide increases bactericidal potency against Gram-positive bacteria, including drug-resistant strains

2004 ◽  
Vol 378 (1) ◽  
pp. 93-103 ◽  
Author(s):  
Nathan A. LOCKWOOD ◽  
Judith R. HASEMAN ◽  
Matthew V. TIRRELL ◽  
Kevin H. MAYO
Keyword(s):  
Fatty Acid ◽  
Fluorescence Spectroscopy ◽  
Bactericidal Activity ◽  
Bacterial Cell ◽  
Membrane Surface ◽  
Peptide Amphiphiles ◽  
Helical Conformation ◽  
Gram Positive ◽  
Bacterial Membranes ◽  
Bactericidal Activities

We have conjugated dodecyl and octadecyl fatty acids to the N-terminus of SC4, a potently bactericidal, helix-forming peptide 12-mer (KLFKRHLKWKII), and examined the bactericidal activities of the resultant SC4 ‘peptide-amphiphile’ molecules. SC4 peptide-amphiphiles showed up to a 30-fold increase in bactericidal activity against Gram-positive strains (Staphylococcus aureus, Streptococcus pyogenes and Bacillus anthracis), including S. aureus strains resistant to conventional antibiotics, but little or no increase in bactericidal activity against Gram-negative bacteria (Escherichia coli and Pseudomonas aeruginosa). Fatty acid conjugation improved endotoxin (lipopolysaccharide) neutralization by 3- to 6-fold. Although acylation somewhat increased lysis of human erythrocytes, it did not increase lysis of endothelial cells, and the haemolytic effects occurred at concentrations 10- to 100-fold higher than those required for bacterial cell lysis. For insight into the mechanism of action of SC4 peptide-amphiphiles, CD, NMR and fluorescence spectroscopy studies were performed in micelle and liposome models of eukaryotic and bacterial cell membranes. CD indicated that SC4 peptide-amphiphiles had the strongest helical tendencies in liposomes mimicking bacterial membranes, and strong membrane integration of the SC4 peptide-amphiphiles was observed using tryptophan fluorescence spectroscopy under these conditions; results that correlated with the increased bactericidal activities of SC4 peptide-amphiphiles. NMR structural analysis in micelles demonstrated that the two-thirds of the peptide closest to the fatty acid tail exhibited a helical conformation, with the positively-charged side of the amphipathic helix interacting more with the model membrane surface. These results indicate that conjugation of a fatty acid chain to the SC4 peptide enhances membrane interactions, stabilizes helical structure in the membrane-bound state and increases bactericidal potency.

Design of bio-molecular interfaces using liquid crystals demonstrating endotoxin interactions with bacterial cell wall components

RSC Advances ◽  
2015 ◽  
Vol 5 (81) ◽  
pp. 66476-66486 ◽  
Author(s):  
Dibyendu Das ◽  
Sumyra Sidiq ◽  
Santanu Kumar Pal
Keyword(s):  
Cell Wall ◽  
Liquid Crystals ◽  
Cell Membrane ◽  
Bacterial Cell ◽  
Bacterial Cell Wall ◽  
Cell Wall Components ◽  
Bacterial Cell Membrane ◽  
Membrane Components ◽  
Wall Components

Liquid crystals offer a promising approach to study and quantify the interactions between different bacterial cell membrane components with endotoxin at an aqueous interface.

Telavancin’s interactions with the bacterial cell membrane

2010 ◽  
Vol 5 (3) ◽  
pp. 355-358 ◽  
Author(s):  
Esteban C Nannini ◽  
Martin E Stryjewski ◽  
G Ralph Corey
Keyword(s):  
Cell Membrane ◽  
Bacterial Cell ◽  
Bacterial Cell Membrane
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