Stretch-Activated Pore of the Antimicrobial Peptide, Magainin 2

Karal, Mohammad Abu Sayem; Alam, Jahangir Md.; Takahashi, Tomoki; Levadny, Victor; Yamazaki, Masahito

doi:10.1021/la503318z

Cited by 112 publications

(233 citation statements)

References 51 publications

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“…6 and 7, we can obtain s eq osm . We measured the value of K bil of a DOPC-GUV in 100 mM sucrose (inside the GUV)/100 mM glucose (outside the GUV) using the standard method (34,35), and obtained its mean value and the standard deviation; K bil ¼ 218 5 26 mN/m (n ¼ 16) (Fig. S2), which is almost the same as reported values (17,35).…”

Section: Measurement Of P-induced Volume Changes Of Dopc-guvssupporting

confidence: 71%

Experimental Estimation of Membrane Tension Induced by Osmotic Pressure

Shibly

Ghatak

Karal

et al. 2016

Biophysical Journal

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Osmotic pressure (P) induces the stretching of plasma membranes of cells or lipid membranes of vesicles, which plays various roles in physiological functions. However, there have been no experimental estimations of the membrane tension of vesicles upon exposure to P. In this report, we estimated experimentally the lateral tension of the membranes of giant unilamellar vesicles (GUVs) when they were transferred into a hypotonic solution. First, we investigated the effect of P on the rate constant, k p , of constant-tension (s ex )-induced rupture of dioleoylphosphatidylcholine (DOPC)-GUVs using the method developed by us recently. We obtained the s ex dependence of k p in GUVs under P and by comparing this result with that in the absence of P, we estimated the tension of the membrane due to P at the swelling equilibrium, s eq osm . Next, we measured the volume change of DOPC-GUVs under small P. The experimentally obtained values of s eq osm and the volume change agreed with their theoretical values within the limits of the experimental errors. Finally, we investigated the characteristics of the P-induced pore formation in GUVs. The s eq osm corresponding to the threshold P at which pore formation is induced is similar to the threshold tension of the s ex -induced rupture. The time course of the radius change of GUVs in the P-induced pore formation depends on the total membrane tension, s t ; for small s t , the radius increased with time to an equilibrium one, which remained constant for a long time until pore formation, but for large s t , the radius increased with time and pore formation occurred before the swelling equilibrium was reached. Based on these results, we discussed the s eq osm and the P-induced pore formation in lipid membranes.

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Section: Measurement Of P-induced Volume Changes Of Dopc-guvssupporting

confidence: 71%

Experimental Estimation of Membrane Tension Induced by Osmotic Pressure

Shibly

Ghatak

Karal

et al. 2016

Biophysical Journal

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“…When the attraction is made, the microbes get oxidized and die instantly. This mechanism of attraction is very similar to the binding of positively charged antimicrobial peptide to the negatively charged lipid membranes of vesicles . Generally, the MNPs release ions, which react with the thiol groups (–SH) of proteins in the bacterial cell membrane that leads to cell lysis .…”

Section: Resultsmentioning

confidence: 94%

Eco‐Friendly Synthesis of Fe₃O₄ Nanoparticles Based on Natural Stabilizers and Their Antibacterial Applications

et al. 2019

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Spinel magnetite (Fe3O4) nanoparticles (MNPs) were successfully synthesized from the reduction of stoichiometric ratio of aqueous solutions of Fe2+ and Fe3+ with NaOH solution. Then naturally available Ipomoea aquatica leaf aqueous extract (IA extract) was used for the surface modification of MNPs where biomolecules of leaf extract were acted as stabilizer. Gas chromatography‐mass spectrometry (GC‐MS), Fourier transform infrared (FT‐IR), and energy dispersive X‐ray (EDX) analyses evidence the proper incorporation of the biomolecules of leaf extract in MNPs. X‐ray diffraction (XRD) confirms the synthesis of MNPs where the uniform size distribution with spherical shape was approved by field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM) analyses. Thermal analysis was performed using differential scanning caloremetry (DSC) and thermogravimetric analysis (TGA) and a phase transition from Fe3O4 to maghemite (γ‐Fe2O3) was detected at 650 °C. The superparamagnetic nature of the studied materials at room temperature was confirmed by vibrating sample magnetometer (VSM) study and the correlation among saturation magnetization (Ms), crystallite size (D), particle size (d), dislocation density (δ), and microstrain (ϵ) were described. The antibacterial activity of the synthesized MNPs was confirmed by investigating the zones of inhibition which were 19 mm for Gram‐negative bacteria Escherichia coli and 14 mm for Gram‐positive bacteria Bacillus subtilis.

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“…Our GUV aspiration experiment (23°C) follows the procedure reported by other groups [26, 28, 32, 50]. Two wells are made by placing silicone sheets (Grace BioLabs, Inc.) on a glass cover slip.…”

Section: Methodsmentioning

confidence: 99%

Modulation of lipid membrane structural and mechanical properties by a peptidomimetic derived from reduced amide scaffold

Khadka¹,

Teng²,

Cai³

et al. 2017

Biochimica et Biophysica Acta (BBA) - Biomembranes

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Understanding how antimicrobial peptidomimetics interact with lipid membranes is important in battling multidrug resistant bacterial pathogens. We study the effects of a recently reported peptidomimetic on lipid bilayer structural and mechanical properties. The compound referred to as E107-3 is synthesized based on the acylated reduced amide scaffold and has been shown to exhibit good antimicrobial potency. Our vesicle leakage essay indicates that the compound increases lipid bilayer permeability. We use micropipette aspiration to explore the kinetic response of giant unilamellar vesicles (GUVs). Exposure to the compound causes the GUV protrusion length LP to spontaneously increase and then decrease, followed by GUV rupture. Solution atomic force microscopy (AFM) is used to visualize lipid bilayer structural modulation within a nanoscopic regime. Unlike melittin, which produces pore-like structures, the peptidomimetic compound is found to induce nanoscopic heterogeneous structures. Finally, we use AFM-based force spectroscopy to study the impact of the compound on lipid bilayer mechanical properties. We find that incremental addition of the compound to planar lipid bilayers results in a moderate decrease of the bilayer puncture force FP and a 39% decrease of the bilayer area compressibility modulus KA. To explain our experimental data, we propose a membrane interaction model encompassing disruption of lipid chain packing and extraction of lipid molecules. The later action mode is supported by our observation of a double-bilayer structure in the presence of fusogenic calcium ions.

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Stretch-Activated Pore of the Antimicrobial Peptide, Magainin 2

Cited by 112 publications

References 51 publications

Experimental Estimation of Membrane Tension Induced by Osmotic Pressure

Experimental Estimation of Membrane Tension Induced by Osmotic Pressure

Eco‐Friendly Synthesis of Fe₃O₄ Nanoparticles Based on Natural Stabilizers and Their Antibacterial Applications

Modulation of lipid membrane structural and mechanical properties by a peptidomimetic derived from reduced amide scaffold

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Stretch-Activated Pore of the Antimicrobial Peptide, Magainin 2

Cited by 112 publications

References 51 publications

Experimental Estimation of Membrane Tension Induced by Osmotic Pressure

Experimental Estimation of Membrane Tension Induced by Osmotic Pressure

Eco‐Friendly Synthesis of Fe3O4 Nanoparticles Based on Natural Stabilizers and Their Antibacterial Applications

Modulation of lipid membrane structural and mechanical properties by a peptidomimetic derived from reduced amide scaffold

Contact Info

Product

Resources

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Eco‐Friendly Synthesis of Fe₃O₄ Nanoparticles Based on Natural Stabilizers and Their Antibacterial Applications