IJMS, Vol. 20, Pages 631: Interaction of Halictine-Related Antimicrobial Peptides with Membrane Models

IJMS, Vol. 20, Pages 631: Interaction of Halictine-Related Antimicrobial Peptides with Membrane Models

International Journal of Molecular Sciences doi: 10.3390/ijms20030631

Authors: Markéta Pazderková Petr Maloň Vlastimil Zíma Kateřina Hofbauerová Vladimír Kopecký Eva Kočišová Tomáš Pazderka Václav Čeřovský Lucie Bednárová

We have investigated structural changes of peptides related to antimicrobial peptide Halictine-1 (HAL-1) induced by interaction with various membrane-mimicking models with the aim to identify a mechanism of the peptide mode of action and to find a correlation between changes of primary/secondary structure and biological activity. Modifications in the HAL-1 amino acid sequence at particular positions, causing an increase of amphipathicity (Arg/Lys exchange), restricted mobility (insertion of Pro) and consequent changes in antimicrobial and hemolytic activity, led to different behavior towards model membranes. Secondary structure changes induced by peptide-membrane interaction were studied by circular dichroism, infrared spectroscopy, and fluorescence spectroscopy. The experimental results were complemented by molecular dynamics calculations. An α-helical structure has been found to be necessary but not completely sufficient for the HAL-1 peptides antimicrobial action. The role of alternative conformations (such as β-sheet, PPII or 310-helix) also seems to be important. A mechanism of the peptide mode of action probably involves formation of peptide assemblies (possibly membrane pores), which disrupt bacterial membrane and, consequently, allow membrane penetration.

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