Effects of antimicrobial peptides on membrane dynamics: A comparison of fluorescence and NMR experiments.

Autor: Roversi D; Department of Chemical Science and Technology, University of Rome Tor Vergata, Rome 00133, Italy., Troiano C; Department of Chemical Science and Technology, University of Rome Tor Vergata, Rome 00133, Italy., Salnikov E; RMN et Biophysique des membranes, Institut de Chimie de Strasbourg, CNRS/UMR 7177, Université de Strasbourg, 4, rue Blaise Pascal, Strasbourg 67000, France., Giordano L; Department of Chemical Science and Technology, University of Rome Tor Vergata, Rome 00133, Italy., Riccitelli F; Department of Chemical Science and Technology, University of Rome Tor Vergata, Rome 00133, Italy., De Zotti M; Department of Chemical Sciences, University of Padova, Padova 35131, Italy., Casciaro B; Department of Biochemical Sciences, Laboratory affiliated to Istituto Pasteur Italia-Fondazione Cenci Bolognetti, Sapienza University of Rome, Rome 00185, Italy., Loffredo MR; Department of Biochemical Sciences, Laboratory affiliated to Istituto Pasteur Italia-Fondazione Cenci Bolognetti, Sapienza University of Rome, Rome 00185, Italy., Park Y; Department of Biomedical Science and Research Center for Proteinaceous Materials (RCPM), Chosun University, Gwangju, Republic of Korea., Formaggio F; Department of Chemical Sciences, University of Padova, Padova 35131, Italy., Mangoni ML; Department of Biochemical Sciences, Laboratory affiliated to Istituto Pasteur Italia-Fondazione Cenci Bolognetti, Sapienza University of Rome, Rome 00185, Italy., Bechinger B; RMN et Biophysique des membranes, Institut de Chimie de Strasbourg, CNRS/UMR 7177, Université de Strasbourg, 4, rue Blaise Pascal, Strasbourg 67000, France; Institut Universitaire de France, Paris 75005, France., Stella L; Department of Chemical Science and Technology, University of Rome Tor Vergata, Rome 00133, Italy. Electronic address: stella@uniroma2.it.
Jazyk: angličtina
Zdroj: Biophysical chemistry [Biophys Chem] 2023 Sep; Vol. 300, pp. 107060. Date of Electronic Publication: 2023 Jun 08.
DOI: 10.1016/j.bpc.2023.107060
Abstrakt: Antimicrobial peptides (AMPs) represent a promising class of compounds to fight resistant infections. They are commonly thought to kill bacteria by perturbing the permeability of their cell membranes. However, bacterial killing requires a high coverage of the cell surface by bound peptides, at least in the case of cationic and amphipathic AMPs. Therefore, it is conceivable that peptide accumulation on the bacterial membranes might interfere with vital cellular functions also by perturbing bilayer dynamics, a hypothesis that has been termed "sand in the gearbox". Here we performed a systematic study of such possible effects, for two representative peptides (the cationic cathelicidin PMAP-23 and the peptaibol alamethicin), employing fluorescence and NMR spectroscopies. These approaches are commonly applied to characterize lipid order and dynamics, but sample different time-scales and could thus report on different membrane properties. In our case, fluorescence anisotropy measurements on liposomes labelled with probes localized at different depths in the bilayer showed that both peptides perturb membrane fluidity and order. Pyrene excimer-formation experiments showed a peptide-induced reduction in lipid lateral mobility. Finally, laurdan fluorescence indicated that peptide binding reduces water penetration below the headgroups region. Comparable effects were observed also in fluorescence experiments performed directly on live bacterial cells. By contrast, the fatty acyl chain order parameters detected by deuterium NMR spectroscopy remained virtually unaffected by addition of the peptides. The apparent discrepancy between the two techniques confirms previous sporadic observations and is discussed in terms of the different characteristic times of the two approaches. The perturbation of membrane dynamics in the ns timescale, indicated by the multiple fluorescence approaches reported here, could contribute to the antimicrobial activity of AMPs, by affecting the function of membrane proteins, which is strongly dependent on the physicochemical properties of the bilayer.
Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
(Copyright © 2023 Elsevier B.V. All rights reserved.)
Databáze: MEDLINE
Externí odkaz: