Effect of natural amphipathic peptides on viability, membrane potential, cell shape and motility of mollicutes

Béven, Laure; Wróblewski, Henri

doi:10.1016/s0923-2508(97)87647-4

Cited by 92 publications

(73 citation statements)

References 42 publications

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“…Hemolysis by C 15 -surfactin has an ED 50 of 13 lM (Kracht et al 1999). The minimum inhibitory concentration for Acholeplasma laidlawii is 12.5 lM (Beven and Wroblewski 1997). The free, aqueous peptide concentration corresponding to an ED 50 is expected to be only slightly lower, since the effective lipid concentration in the assays is usually too small (typically £1 mM) to bind a major fraction of the peptide.…”

Section: Leakage and Antibiotic Activitymentioning

confidence: 99%

“…We may conclude that the biologically active concentration of the peptide is of the same order as that inducing destabilization and leakage of POPC vesicles. The induction of an asymmetry between the inner and outer leaflet results in strains and local changes in shape and motility (Beven and Wroblewski 1997), it interferes with endocytosis and exocytosis (Rauch and Farge 2000), and, ultimately, it causes transient membrane failure. Whether these effects suffice to kill the target cell, thus being the relevant mechanism of antibiotic activity, remains to be established.…”

Section: Leakage and Antibiotic Activitymentioning

confidence: 99%

“…Surfactin is highly surface active, which may play a key role for the motility of the bacillus (Kinsinger et al 2003) as well as for technical applications (Cameotra and Makkar 2004). Given the great interest in the development of new peptide antibiotics, it is of particular relevance that surfactin possesses also hemolytic (Kracht et al 1999), anti-viral (Kracht et al 1999;Vollenbroich et al 1997a), anti-bacterial (Beven and Wroblewski 1997;Vollenbroich et al 1997b), and anti-tumor (Kameda et al 1974) activity. It is generally believed that these properties result from its capability of permeabilizing cellular membranes and viral envelopes.…”

Section: Introductionmentioning

confidence: 99%

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Leakage and lysis of lipid membranes induced by the lipopeptide surfactin

2006

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Surfactin is a lipopeptide produced by Bacillus subtilis which possesses antimicrobial activity. We have studied the leakage and lysis of POPC vesicles induced by surfactin using calcein fluorescence de-quenching, isothermal titration calorimetry and 31 P solid state NMR. Membrane leakage starts at a surfactin-to-lipid ratio in the membrane, R b % 0.05, and an aqueous surfactin concentration of C S w % 2 lM. The transient, graded nature of leakage and the apparent coupling with surfactin translocation to the inner leaflet of the vesicles, suggests that this low-concentration effect is due to a bilayer-couple mechanism. Different permeabilization behaviour is found at R b % 0.15 and attributed to surfactin-rich clusters, which can induce leaks and stabilize them by covering their hydrophobic edges. Membrane lysis or solubilization to micellar structures starts at R b sat = 0.22 and C S w = 9 lM and is completed at R m sol = 0.43 and C S w = 11 lM. The membrane-water partition coefficient of surfactin is obtained as K = 2 · 10 4 M -1 . These data resolve inconsistencies in the literature and shed light on the variety of effects often referred to as detergent-like effects of antibiotic peptides on membranes. The results are compared with published parameters characterizing the hemolytic and antibacterial activity.

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Section: Leakage and Antibiotic Activitymentioning

confidence: 99%

Section: Leakage and Antibiotic Activitymentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Leakage and lysis of lipid membranes induced by the lipopeptide surfactin

2006

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“…mycoides SC KH3J, Spiroplasma citri R8A2, S. floricola BNR1, and S. melliferum BC3 were cultured as described previously [30]. The minimal inhibitory concentrations (MICs) were determined in 96-well microtitre plates by growing the In addition, to determine the influence of the hydrophobic core thickness of the cell membrane on peptide antibiotic activity, A. laidlawii A-EF22 was adapted to grow in a lipid-free medium supplemented with appropriate fatty acids, as described previously [32,33].…”

Section: Antimicrobial Assaysmentioning

confidence: 99%

“…Dark-field optics were used to analyse the effects of the peptides on spiroplasma motility and cell morphology, as described previously [30,[33][34][35].…”

Section: Light Microscopymentioning

confidence: 99%

The antibiotic activity of cationic linear amphipathic peptides: lessons from the action of leucine/lysine copolymers on bacteria of the class Mollicutes

Béven

Castano

Dufourcq

et al. 2003

European Journal of Biochemistry

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Peptides composed of leucyl and lysyl residues (ÔLK peptidesÕ) with different compositions and sequences were compared for their antibacterial activities using cell wall-less bacteria of the class Mollicutes (acholeplasmas, mycoplasmas and spiroplasmas) as targets. The antibacterial activity of the amphipathic a-helical peptides varied with their size, 15 residues being the optimal length, independent of the membrane hydrophobic core thickness and the amount of cholesterol. The 15-residue ideally amphipathic a helix with a +5 positive net charge (KLLKLLLKLLLKLLK) had the strongest antibacterial activity, similar to that of melittin. In contrast, scrambled peptides devoid of amphipathy and the less hydrophobic b-sheeted peptides [(LK) n K], even those 15-residue long, were far less potent than the helical ones. Furthermore, the growth inhibitory activity of the peptides was correlated with their ability to abolish membrane potential. These data are fully consistent with a predominantly flat orientation of LK peptides at the lipid/ water interface and strongly supports that these peptides and probably the linear polycationic amphipathic defence peptides act on bacterial membranes in four main steps according to the ÔcarpetÕ model: (a) interfacial partitioning with accumulation of monomers on the target membrane (limiting step); (b) peptide structural changes (conformation, aggregation, and orientation) induced by interactions with the lipid bilayer (as already shown with liposomes and erythrocytes); (c) plasma membrane permeabilization/ depolarization via a detergent-like effect; and (d) rapid bacterial cell death if the extent of depolarization is maintained above a critical threshold.Keywords: amphipathic peptides; antibacterial activity; bacterial cell death; membrane depolarization; mollicutes.The amphipathic a helix concept helps in understanding the behaviour of very different classes of proteins and peptides, especially those acting on membranes [1][2][3][4]. This concept, which has been useful in the field of peptidic cytotoxins to develop new analogues, and to better understand their mode of action [5][6][7], is still the basis for the rational design of new antimicrobial compounds, i.e. analogues or chimeras of natural products [8], or radically new molecules [9,10].The need to understand their mode of action and improve their efficacy and/or selectivity towards microorganisms led to the synthesis of new active peptides, made possible largely by the progress in solid state synthesis. As a result, a large wealth of information was obtained on many natural peptides endowed with cytotoxic (including antimicrobial) activity. However, answers are still missing regarding: (a) the requirements for optimized activity and selectivity; and (b) the mechanisms of action, especially in bacterial cells. In an effort of rationalization, a minimalistic approach was initiated by the pioneering work of De Grado and Lear [11] using residue substitutions or designing simplified sequences [2,[12][13][14]. Using the very mini...

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Peptaibiotics and peptaibols from fungi

Zeilinger

2015

Fungal Biomolecules

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Effect of natural amphipathic peptides on viability, membrane potential, cell shape and motility of mollicutes

Cited by 92 publications

References 42 publications

Leakage and lysis of lipid membranes induced by the lipopeptide surfactin

Leakage and lysis of lipid membranes induced by the lipopeptide surfactin

The antibiotic activity of cationic linear amphipathic peptides: lessons from the action of leucine/lysine copolymers on bacteria of the class Mollicutes

Peptaibiotics and peptaibols from fungi

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