Restructuring of lipid membranes by an arginine-capped peptide bolaamphiphile

Castelletto, V., Barnes, R. H., Karatzas, K.-A., Edwards-Gayle, C. J. C., Greco, F., Hamley, I. W. ORCID: https://orcid.org/0000-0002-4549-0926, Seitsonen, J. and Ruokolainen, J. (2019) Restructuring of lipid membranes by an arginine-capped peptide bolaamphiphile. Langmuir, 35 (5). pp. 1302-1311. ISSN 0743-7463 doi: 10.1021/acs.langmuir.8b01014

Abstract/Summary

We study the self-assembly of arginine-capped bolaamphiphile peptide RA3R (A: alanine, R: arginine) together with its binding to model membranes and its cytotoxicity and antimicrobial activity. Anionic 2-oleoyl-1-palmitoyl-sn-glycero-3-phospho-rac-(1-glycerol) sodium salt/2-oleoyl-1-palmitoyl-sn-glycero-3-phosphoethanolamine (POPG/POPE) vesicles and zwitterionic 1,2-dioleoyl-sn-glycero-3-phosphocholine/2-oleoyl-1-palmitoyl-sn-glycero-3-phosphocholine (POPC/DOPC) vesicles are used as model membranes to mimic bacterial and mammalian cell membranes, respectively. We show that RA3R adopts a polyproline-II collagen-like conformation in water. Binding of RA3R to POPG/POPE vesicles induces a strong correlation between the lipid bilayers, driven by RA3R/POPG attractive electrostatic interaction together with a shift of the intramolecular POPE zwitterionic interaction toward an attractive electrostatic interaction with the RA3R. Populations of RA3R/POPG/POPE vesicles comprise different bilayer spacings, dA and dB, controlled by the conformation of the lipid chains corresponding to the Lβ (gel-like) and Lα (liquid-crystal) phases, respectively. Cryo-TEM images reveal the presence of vesicles with no internal structure, compartmentalized thin-wall vesicles, or multilayer vesicles with uncorrelated layers and compartmentalization depending on the RA3R/POPG/POPE composition. In contrast, the interaction of RA3R with multilamellar POPC/DOPC vesicles leads to the decorrelation of the lipid bilayers. RA3R was tolerated by skin fibroblast cells for a concentration up to 0.01 wt %, while 0.25 wt % RA3R proved to be an efficient antibacterial agent against Gram-positive bacteria L. monocytogenes. Our results highlight the ability of RA3R to distinguish between bacterial and mammalian cells and establish this peptide as a candidate to reduce the proliferation of L. monocytogenes bacteria.

Item Type	Article
URI	https://reading-clone.eprints-hosting.org/id/eprint/78789
Item Type	Article
Refereed	Yes
Divisions	Life Sciences > School of Chemistry, Food and Pharmacy > Department of Chemistry Life Sciences > School of Chemistry, Food and Pharmacy > Department of Food and Nutritional Sciences > Food Microbial Sciences Research Group
Uncontrolled Keywords	Spectroscopy, Electrochemistry, General Materials Science, Surfaces and Interfaces, Condensed Matter Physics
Publisher	American Chemical Society
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