Details

Autor(en) / Beteiligte

• Nielsen, Josefine Eilsø
• Lind, Tania Kjellerup
• Lone, Abdullah
• Gerelli, Yuri
• Hansen, Paul Robert
• Jenssen, Håvard
• Cárdenas, Marité
• Lund, Reidar

Titel

A biophysical study of the interactions between the antimicrobial peptide indolicidin and lipid model systems

Ist Teil von

• Biochimica et biophysica acta. Biomembranes, 2019-07, Vol.1861 (7), p.1355-1364

Ort / Verlag

Netherlands: Elsevier B.V

Erscheinungsjahr

2019

Link zum Volltext

Quelle

Elsevier ScienceDirect Journals

Beschreibungen/Notizen

• The naturally occurring peptide indolicidin from bovine neutrophils exhibits strong biological activity against a broad spectrum of microorganisms. This is believed to arise from selective interactions with the negatively charged cytoplasmic lipid membrane found in bacteria. We have investigated the peptide interaction with supported lipid model membranes using a combination of complementary surface sensitive techniques: neutron reflectometry (NR), atomic force microscopy (AFM), and quartz crystal microbalance with dissipation monitoring (QCM-D). The data are compared with small-angle X-ray scattering (SAXS) results obtained with lipid vesicle/peptide solutions. The peptide membrane interaction is shown to be significantly concentration dependent. At low concentrations, the peptide inserts at the outer leaflet in the interface between the headgroup and tail core. Insertion of the peptide results in a slight decrease in the lipid packing order of the bilayer, although not sufficient to cause membrane thinning. By increasing the indolicidin concentration well above the physiologically relevant conditions, a deeper penetration of the peptide into the bilayer and subsequent lipid removal take place, resulting in a slight membrane thinning. The results suggest that indolicidin induces lipid removal and that mixed indolicidin-lipid patches form on top of the supported lipid bilayers. Based on the work presented using model membranes, indolicidin seems to act through the interfacial activity model rather than through the formation of stable pores. [Display omitted] •The lipid interaction of antimicrobial peptides is studied by neutrons and X-rays.•The interaction of indolicidin on model lipid membranes is concentration dependent.•At low concentrations indolicidin does not penetrate through the membrane.•Indolicidin induce significant lipid removal at higher concentrations.•Indolicidin seems to disrupt the membranes in a disordered fashion.