Antimicrobial Activity and Protection from Triton X-100-Induced Mammalian Cell Membrane Lysis by Artificial Amphiphilic Peptides

ABSTRACT Chitosan is a polysaccharide biopolymer that combines a unique set of versatile physicochemical and biological characteristics which allow for a wide range of applications. Although its antimicrobial activity is well documented, its mode of action has hitherto remained only vaguely defined. In this work we investigated the antimicrobial mode of action of chitosan using a combination of approaches, including in vitro assays, killing kinetics, cellular leakage measurements, membrane potential estimations, and electron microscopy, in addition to transcriptional response analysis. Chitosan, whose antimicrobial activity was influenced by several factors, exhibited a dose-dependent growth-inhibitory effect. A simultaneous permeabilization of the cell membrane to small cellular components, coupled to a significant membrane depolarization, was detected. A concomitant interference with cell wall biosynthesis was not observed. Chitosan treatment of Staphylococcus simulans 22 cells did not give rise to cell wall lysis; the cell membrane also remained intact. Analysis of transcriptional response data revealed that chitosan treatment leads to multiple changes in the expression profiles of Staphylococcus aureus SG511 genes involved in the regulation of stress and autolysis, as well as genes associated with energy metabolism. Finally, a possible mechanism for chitosan's activity is postulated. Although we contend that there might not be a single classical target that would explain chitosan's antimicrobial action, we speculate that binding of chitosan to teichoic acids, coupled with a potential extraction of membrane lipids (predominantly lipoteichoic acid) results in a sequence of events, ultimately leading to bacterial death.

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Antimicrobial Activity of Phenyllactic Acid AgainstEnterococcus faecalisand Its Effect on Cell Membrane

Foodborne Pathogens and Disease ◽

10.1089/fpd.2018.2470 ◽

2018 ◽

Vol 15 (10) ◽

pp. 645-652 ◽

Cited By ~ 3

Author(s):

Fengting Wang ◽

Haihong Wu ◽

Panpan Jin ◽

Zhilan Sun ◽

Fang Liu ◽

...

Keyword(s):

Antimicrobial Activity ◽

Cell Membrane ◽

Phenyllactic Acid

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Affordable Membrane Permeability Calculations: Permeation of Short-Chain Alcohols through Pure-Lipid Bilayers and a Mammalian Cell Membrane

Journal of Chemical Theory and Computation ◽

10.1021/acs.jctc.9b00022 ◽

2019 ◽

Vol 15 (5) ◽

pp. 2913-2924 ◽

Cited By ~ 2

Author(s):

Chi Hang Tse ◽

Jeffrey Comer ◽

Simon Kit Sang Chu ◽

Yi Wang ◽

Christophe Chipot

Keyword(s):

Cell Membrane ◽

Membrane Permeability ◽

Lipid Bilayers ◽

Mammalian Cell ◽

Short Chain

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Cytoplasmic Membrane Lipoprotein LppC ofStreptococcus equisimilis Functions as an Acid Phosphatase

Applied and Environmental Microbiology ◽

10.1128/aem.64.7.2439-2442.1998 ◽

1998 ◽

Vol 64 (7) ◽

pp. 2439-2442 ◽

Cited By ~ 25

Author(s):

Horst Malke

Keyword(s):

Acid Phosphatase ◽

Cell Membrane ◽

Cytoplasmic Membrane ◽

Structural Homology ◽

Whole Cells ◽

Specific Enzymatic Activity ◽

Acidic Conditions ◽

Membrane Lipoprotein ◽

Triton X ◽

Membrane Lipoproteins

ABSTRACT The function of the streptococcal cytoplasmic membrane lipoprotein, LppC, was identified with isogenic Streptococcus equisimilis H46A and Escherichia coli JM109 strain pairs differing in whether they contained [H46A and JM109(pLPP2)] or lacked (H46A lppC::pLPP10 and JM109) the functional lppC gene for comparative phosphatase determinations under acidic conditions. lppC-directed acid phosphatase activity was demonstrated zymographically and by specific enzymatic activity assays, with whole cells or cell membrane preparations as enzyme sources. LppC acid phosphatase showed optimum activity at pH 5, and the enzyme activity was unaffected by Triton X-100, l-(+)-tartaric acid, or EDTA. Database searches revealed significant structural homology of LppC to the Streptococcus pyogenes LppA,Flavobacterium meningosepticum OplA, Helicobacter pylori HP1285, and Haemophilus influenzae Hel [e (P4)] proteins. These results suggest a possible function for these proteins and establish a novel function of streptococcal cell membrane lipoproteins.

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Enhancement of antibiotics antimicrobial activity due to the silver nanoparticles impact on the cell membrane

PLoS ONE ◽

10.1371/journal.pone.0224904 ◽

2019 ◽

Vol 14 (11) ◽

pp. e0224904 ◽

Cited By ~ 23

Author(s):

R. Vazquez-Muñoz ◽

A. Meza-Villezcas ◽

P. G. J. Fournier ◽

E. Soria-Castro ◽

K. Juarez-Moreno ◽

...

Keyword(s):

Antimicrobial Activity ◽

Silver Nanoparticles ◽

Cell Membrane

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Simplified Head-to-Tail Cyclic Polypeptides as Biomaterial-Associated Antimicrobials with Endotoxin Neutralizing and Anti-Inflammatory Capabilities

International Journal of Molecular Sciences ◽

10.3390/ijms20235904 ◽

2019 ◽

Vol 20 (23) ◽

pp. 5904 ◽

Cited By ~ 1

Author(s):

Na Dong ◽

Chensi Wang ◽

Xinran Li ◽

Yuming Guo ◽

Xiaoli Li

Keyword(s):

Antimicrobial Activity ◽

Antimicrobial Peptides ◽

Cyclic Peptide ◽

Skin Inflammation ◽

Rational Approach ◽

Inflammatory Factor ◽

Potential Candidate ◽

Dependent Manner ◽

Amphiphilic Peptides ◽

Tnf Α

The therapeutic application of antimicrobial peptides (AMPs), a potential type of peptide-based biomaterial, is impeded by their poor antimicrobial activity and potential cytotoxicity as a lack of understanding of their structure–activity relationships. In order to comprehensively enhance the antibacterial and clinical application potency of AMPs, a rational approach was applied to design amphiphilic peptides, including head-to-tail cyclic, linear and D-proline antimicrobial peptides using the template (IR)nP(IR)nP (n = 1, 2 and 3). Results showed that these amphiphilic peptides demonstrated antimicrobial activity in a size-dependent manner and that cyclic peptide OIR3, which contained three repeating units (IR)3, had greater antimicrobial potency and cell selectivity than liner peptide IR3, DIR3 with D-Pro and gramicidin S (GS). Surface plasmon resonance and endotoxin neutralization assays indicated that OIR3 had significant endotoxin neutralization capabilities, which suggested that the effects of OIR3 were mediated by binding to lipopolysaccharides (LPS). Using fluorescence spectrometry and electron microscopy, we found that OIR3 strongly promoted membrane disruption and thereby induced cell lysis. In addition, an LPS-induced inflammation assay showed that OIR3 inhibited the pro-inflammatory factor TNF-α in RAW264.7 cells. OIR3 was able to reduce oxazolone-induced skin inflammation in allergic dermatitis mouse model via the inhibition of TNF-α, IL-1β and IL-6 mRNA expression. Collectively, the engineered head-to-tail cyclic peptide OIR3 was considerable potential candidate for use as a clinical therapeutic for the treatment of bacterial infections and skin inflammation.

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The characterization and interconversion of three forms of cholesterol oxidase extracted from Nocardia rhodochrous

Biochemical Journal ◽

10.1042/bj2010515 ◽

1982 ◽

Vol 201 (3) ◽

pp. 515-521 ◽

Cited By ~ 41

Author(s):

P S J Cheetham ◽

P Dunnill ◽

M D Lilly

Keyword(s):

Cell Membrane ◽

Membrane Lipids ◽

Cholesterol Oxidase ◽

Hydrophobic Region ◽

Hydrophobic Domain ◽

Solubilized Enzyme ◽

High Concentrations ◽

Triton X ◽

Catalytic Functions ◽

Hydrophobic Anchor

The physical properties and the methods used for interconversion of three forms of cholesterol oxidase extracted from Nocardia rhodochrous by treatment with Triton X-100, trypsin or buffer alone provide evidence that these forms differ chiefly in the possession or absence of a hydrophobic anchor region connected by a trypsin-sensitive region. The hydrophobic domain normally integrates the enzyme into the cell membrane and confers amphipathic properties on the solubilized enzyme, causing adsorption to hydrophobic resins, aggregation when detergent is removed and formation of mixed micelles with detergent and cholesterol resulting in surface-dilution kinetic behaviour and activation by relatively high concentrations of water-miscible solvents. By contrast, only the enzymic fragment is extracted with trypsin and it behaves as a conventional soluble enzyme and does not aggregate or interact with hydrophobic resins, detergents or water-miscible solvents. As no phospholipid could be detected in the enzyme extracts, the detergent appears to act as a substitute for the cell-membrane lipids that would normally interact with the hydrophobic region. This cholesterol oxidase is an example of a prokaryotic enzyme possessing two closely associated catalytic functions, dehydrogenase and isomerase activities, and an anchoring function.

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