Design of peptide-membrane interactions to modulate single-file water transport through modified gramicidin channels.
|Design of peptide-membrane interactions to modulate single-file water transport through modified gramicidin channels.
|Year of Publication
|Portella, Guillem, Polupanow Tanja, Zocher Florian, Boytsov Danila A., Pohl Peter, Diederichsen Ulf, and de Groot Bert L.
|2012 Oct 17
|Acylation, Cell Membrane, Gramicidin, Lipid Bilayers, Molecular Dynamics Simulation, Permeability, Water
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.