Design of peptide-membrane interactions to modulate single-file water transport through modified gramicidin channels.

TitleDesign of peptide-membrane interactions to modulate single-file water transport through modified gramicidin channels.
Publication TypeJournal Article
Year of Publication2012
AuthorsPortella, Guillem, Polupanow Tanja, Zocher Florian, Boytsov Danila A., Pohl Peter, Diederichsen Ulf, and de Groot Bert L.
JournalBiophys J
Volume103
Pagination1698-705
Date Published2012 Oct 17
ISSN1542-0086
KeywordsAcylation, Cell Membrane, Gramicidin, Lipid Bilayers, Molecular Dynamics Simulation, Permeability, Water
Abstract

Water permeability through single-file channels is affected by intrinsic factors such as their size and polarity and by external determinants like their lipid environment in the membrane. Previous computational studies revealed that the obstruction of the channel by lipid headgroups can be long-lived, in the range of nanoseconds, and that pore-length-matching membrane mimetics could speed up water permeability. To test the hypothesis of lipid-channel interactions modulating channel permeability, we designed different gramicidin A derivatives with attached acyl chains. By combining extensive molecular-dynamics simulations and single-channel water permeation measurements, we show that by tuning lipid-channel interactions, these modifications reduce the presence of lipid headgroups in the pore, which leads to a clear and selective increase in their water permeability.

DOI10.1016/j.bpj.2012.08.059