Mechanism of magainin 2a induced permeabilization of phospholipid vesicles

Grant, Earl; Beeler, Troy; Taylor, Kenneth M.; Gable, Kenneth; Roseman, M.

doi:10.1021/bi00156a008

Cited by 95 publications

(97 citation statements)

References 24 publications

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“…Evaluation of membrane sensitivity to nisin by using CF efflux. The 5Ј(6Ј)-carboxyfluorescein (CF; Sigma) efflux assay is widely used to characterize the interaction of antimicrobials and lipid membrane vesicles, giving insight into the antimicrobials' modes of action (17,43). Large unilamellar vesicles loaded with fluorescent dye were constructed from L. monocytogenes grown under different conditions.…”

Section: Methodsmentioning

confidence: 99%

Temperature- and Surfactant-Induced Membrane Modifications That Alter Listeria monocytogenes Nisin Sensitivity by Different Mechanisms

Chikindas

Ludescher

et al. 2002

Appl Environ Microbiol

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Nisin interacts with target membranes in four sequential steps: binding, insertion, aggregation, and pore formation. Alterations in membrane composition might influence any of these steps. We hypothesized that cold temperatures (10°C) and surfactant (0.1% Tween 20) in the growth medium would influence Listeria monocytogenes membrane lipid composition, membrane fluidity, and, as a result, sensitivity to nisin. Compared to the membranes of cells grown at 30°C, those of L. monocytogenes grown at 10°C had increased amounts of shorter, branched-chain fatty acids, increased fluidity (as measured by fluorescence anisotropy), and increased nisin sensitivity. When 0.1% Tween 20 was included in the medium and the cells were cultured at 30°C, there were complex changes in lipid composition. They did not influence membrane fluidity but nonetheless increased nisin sensitivity. Further investigation found that these cells had an increased ability to bind radioactively labeled nisin. This suggests that the modification of the surfactant-adapted cell membrane increased nisin sensitivity at the binding step and demonstrates that each of the four steps can contribute to nisin sensitivity.Listeria monocytogenes is a gram-positive, non-spore-forming food-borne pathogen that can grow at refrigeration temperatures (31, 41). L. monocytogenes has a sophisticated strategy to overcome environmental stresses, such as cold (23, 38), heat (35), an acidic environment (27), and osmotic shock (4). L. monocytogenes is of particular interest with respect to food safety due to its psychrotrophic nature (41), which may result in the enrichment of L. monocytogenes in foods at refrigeration temperature (15). This organism can pose a serious health threat to high-risk populations, such as immunocompromised individuals, newborns, and pregnant women. (42).Nisin is used as an antimicrobial agent against L. monocytogenes. The bactericidal activity of nisin is due to pore formation in the bacterial membrane (12), which occurs through a four-step process of binding, insertion, aggregation, and pore formation. The cell's sensitivity to nisin is influenced by the membrane's lipid composition (24), which might act on any of the four steps. Nisin-resistant L. monocytogenes has a lowered cellular phospholipid content and an altered membrane fatty acid composition. (11,24,25).The cytoplasmic membrane is the primary barrier between the cell and its environment. Environmental factors, especially temperature, influence membrane fluidity by modifying the membrane's lipid composition (19,23). The process of maintaining fluidity, called homeoviscous adaptation (34,29,45), is critical for cell growth at nonoptimal temperatures (5, 20). The concept of membrane fluidity covers the thermal mobility of membrane proteins as well as the microviscosity of the membrane lipid bilayer (33). However, the primary way that bacteria maintain constant membrane fluidity at different growth temperatures is by adjusting their fatty acid compositions (1,5,29). For instance, there are hig...

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Section: Methodsmentioning

confidence: 99%

Temperature- and Surfactant-Induced Membrane Modifications That Alter Listeria monocytogenes Nisin Sensitivity by Different Mechanisms

Chikindas

Ludescher

et al. 2002

Appl Environ Microbiol

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“…84,[87][88][89]120,126,130,131 A few examples demonstrate this effect: (a) The kinetics of magainin-2 induced release of 6-carboxyfluorescein (CF) from phosphatidylserine liposomes indicating that the fast release of dye is a transient effect resulting from transient destabilization of the bilayer upon initial interaction with the peptide. 131 No measurable CF release could be observed until a high level of bound magainin was achieved; (b) The ability of magainin-2 to decrease the membrane potential in cytochrome oxidase liposomes was investigated by Juretic et al 120 At low concentrations the peptide was almost inactive, but activity was observed when a critical concentration was reached. (c) Neutron in-plane scattering detects pores formed by magainin-2 in membranes only when a substantial fraction of the peptide is oriented perpendicular to the membrane.…”

Section: Membrane Permeation By Antimicrobial Peptides Occurs After Amentioning

confidence: 99%

Mode of action of linear amphipathic α-helical antimicrobial peptides

1998

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“…4), buforin II forms an amphipathic helical structure. For magainins [4,5] this geometry is considered the key factor for the formation of transmembrane pores, which will lead to cell death. In the regular c~-helical geometry, amphipathic region of buforin II is limited to residues Pro 11 to Lys 21 (Fig.…”

Section: L18 ~ F10mentioning

confidence: 99%

“…It interacts with bacterial a~. :l acidic model membranes [4] and destroys the ionic gradient across the cell membranes by forming ion channels [5]. F, r the buforin peptides, the structure and the detailed mechawtsm of the activity have not been resolved yet.…”

Section: Introductionmentioning

confidence: 99%

Solution structure of an antimicrobial peptide buforin II

Park

Kim

et al. 1996

FEBS Letters

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The structure of 21-residue antimicrobial peptide buforin II has been determined by using NMR spectroscopy and restrained molecular dynamics. Buforin II adopts a flexible random structure in H20. In trifluoroethanol (TFE)/H20 (1 : 1, vlvi mixture, however, buforin II assumes a regular m-helix between residues Va112 and Arg 2° and a distorted helical structure between residues Gly 7 and Pro n. The model structure obtained shows an amphipathic character in the region from Arg 5 to the C-terminus, Lys 2z. Like other known cationic antimicrobial peptides, the amphipathic structure might be the key factor for antimicrobial activity of buforin II.

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Mechanism of magainin 2a induced permeabilization of phospholipid vesicles

Cited by 95 publications

References 24 publications

Temperature- and Surfactant-Induced Membrane Modifications That Alter Listeria monocytogenes Nisin Sensitivity by Different Mechanisms

Temperature- and Surfactant-Induced Membrane Modifications That Alter Listeria monocytogenes Nisin Sensitivity by Different Mechanisms

Mode of action of linear amphipathic α-helical antimicrobial peptides

Solution structure of an antimicrobial peptide buforin II

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