Table of Contents
Journal of Biophysics
Volume 2010, Article ID 179641, 12 pages
http://dx.doi.org/10.1155/2010/179641
Research Article

Exploring the Membrane Mechanism of the Bioactive Peptaibol Ampullosporin A Using Lipid Monolayers and Supported Biomimetic Membranes

1UMR 6022 CNRS Génie Enzymatique et Cellulaire, Université de Technologie de Compiègne, BP 20529, 60205 Compiègne Cedex, France
2CBMN, Chimie et Biologie des Membranes et des Nanoobjets CNRS, UMR 5248, Université de Bordeaux I, ENITAB, 33607 Pessac, France
3CNRS, UMR 5253 Institut Charles Gerhardt, Université Montpellier 2, Ecole Nationale Supérieure de Chimie de Montpellier, Université Montpellier 1, 34093 Montpellier Cedex, France
4Université de Nîmes, 30000 Nîmes, France
5INRA, UMR 1090 Génomique Diversité et Pouvoir Pathogène, 33883 Villenave d'Ornon, France
6Université de Bordeaux 2, UMR 1090 Génomique Diversité Pouvoir Pathogène, 33883 Villenave d'Ornon Cedex, France

Received 27 October 2010; Revised 9 December 2010; Accepted 20 December 2010

Academic Editor: Miguel Castanho

Copyright © 2010 Marguerita Eid et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Ampullosporin A is an antimicrobial, neuroleptic peptaibol, the behavior of which was investigated in different membrane mimetic environments made of egg yolk L-α-phosphatidylcholine. In monolayers, the peptaibol adopted a mixed α/310-helical structure with an in-plane orientation. The binding step was followed by the peptide insertion into the lipid monolayer core. The relevance of the inner lipid leaflet nature was studied by comparing ampullosporin binding on a hybrid bilayer, in which this leaflet was a rigid alkane layer, and on supported fluid lipid bilayers. The membrane binding was examined by surface plasmon resonance spectroscopy and the effect on lipid dynamics was explored using fluorescence recovery after photobleaching. In the absence of voltage and at low concentration, ampullosporin A substantially adsorbed onto lipid surfaces and its interaction with biomimetic models was strongly modified depending on the inner leaflet structure. At high concentration, ampullosporin A addition led to the lipid bilayers disruption.