Membrane binding properties of plant defensins

Mahdi Shahmiri; Mark R Bleackley; Charlotte S Dawson; Nicole L van der Weerden; Marilyn A Anderson; Adam Mechler

doi:10.1016/j.phytochem.2023.113618

Membrane binding properties of plant defensins

Phytochemistry. 2023 May:209:113618. doi: 10.1016/j.phytochem.2023.113618. Epub 2023 Feb 23.

Authors

Mahdi Shahmiri¹, Mark R Bleackley², Charlotte S Dawson², Nicole L van der Weerden², Marilyn A Anderson², Adam Mechler³

Affiliations

¹ Department of Chemistry and Physics, La Trobe Institute for Molecular Science, La Trobe University, Bundoora, Vic, 3086, Australia; Department of Medical Nanotechnology, School of Advanced Technologies in Medicine (SATiM), Tehran University of Medical Sciences, Tehran, Iran.
² Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Bundoora, Vic, 3086, Australia.
³ Department of Chemistry and Physics, La Trobe Institute for Molecular Science, La Trobe University, Bundoora, Vic, 3086, Australia. Electronic address: a.mechler@latrobe.edu.au.

PMID: 36828099
DOI: 10.1016/j.phytochem.2023.113618

Abstract

The membrane interaction characteristics of five antifungal plant defensin peptides: NaD1, and the related HXP4 and L5, as well as NaD2 and the related ZmD32 were studied. These peptides were chosen to cover a broad range of cationic charges with little structural variations, allowing for assessment of the role of charge in their membrane interactions. Membrane permeabilizing activity against C. albicans was confirmed and quantified for benchmarking purposes. Viscoelastic characteristics of the membrane interactions were studied in typical neutral and charged model membranes using quartz crystal microbalance with dissipation (QCM-D. Frequency-dissipation fingerprinting analysis of the QCM-D results revealed that all of the peptides were able to bind to all studied model membranes albeit with slightly different viscoelastic character for each membrane type. However, characteristic disruption patterns were not observed suggesting that the membrane disrupting activity of these defensins is mostly specific to fungal membranes, and that increasing the peptide charge does not enhance their action. The results also show that the presence of specific sterols has a profound effect on the ability of the peptides to disrupt the membrane.

Keywords: Antifungal peptide; Cationic charge; Defensin; Membrane permeabilization; Quartz crystal microbalance with dissipation.

MeSH terms

Defensins* / chemistry
Peptides*

Substances

Peptides
Defensins