Magainin-H2 effects on the permeabilization and mechanical properties of giant unilamellar vesicles

JOURNAL OF COLLOID AND INTERFACE SCIENCE

卷:553

Article

Mescola, Andrea¹  Marin-Medina, Nathaly²  Ragazzini, Gregorio^1,3  Accolla, Maurizio³  Alessandrini, Andrea^1,3 

[1] CNR, Nanosci Inst S3, Via Campi 213-A, I-41125 Modena, Italy

[2] Univ Los Andes, Dept Phys, Carrera 1 18A-12, Bogota, Colombia

[3] Univ Modena & Reggio Emilia, Dept Phys Informat & Math, Via Campi 213-A, I-41125 Modena, Italy

关键词: Antimicrobial peptides;    Magainin H2;    Micropipette aspiration;    Giant unilamellar vesicles;    Flickering spectroscopy;    Optical microscopy;   

DOI  :  10.1016/j.jcis.2019.06.028

来源: Elsevier

【 摘 要 】

Among the potential novel therapeutics to treat bacterial infections, antimicrobial peptides (AMPs) are a very promising substitute due to their broad-spectrum activity and rapid bactericidal action. AMPs strongly interact with the bacterial membrane, and the need to have a correct understanding of the interaction between AMPs and lipid bilayers at a molecular level prompted a wealth of experimental and theoretical studies exploiting a variety of AMPs. Here, we studied the effects of magainin H2 (Mag H2), an analog of the well-known magainin 2 (wt Mag 2) AMP endowed with a higher degree of hydrophobicity, on giant unilamellar vesicles (GUVs) concentrating on its permeabilization activity and the effect on the lipid bilayer mechanical properties. We demonstrated that the increased hydrophobicity of Mag H2 affects its selectivity conferring a strong permeabilization activity also on zwitterionic lipid bilayers. Moreover, when lipid mixtures including PG lipids are considered, PG has a protective effect, at variance from wt Mag 2, suggesting that for Mag H2 the monolayer curvature could prevail over the peptide-membrane electrostatic interaction. We then mechanically characterized GUVs by measuring the effect of Mag H2 on the bending constant of lipid bilayers by flickering spectroscopy and, by using micropipette aspiration technique, we followed the steps leading to vesicle permeabilization. We found that Mag H2, not with standing its enhanced hydrophobicity, has a pore formation mechanism compatible with the toroidal pore model similar to that of wt Mag 2. (C) 2019 Elsevier Inc. All rights reserved.

【 授权许可】

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