Peptide-related alterations of membrane-associated water: deuterium solid-state NMR investigations of phosphatidylcholine membranes at different hydration levels

✍ Scribed by Cléria Mendonça Moraes; Burkhard Bechinger

• Book ID: 102529371
• Publisher: John Wiley and Sons
• Year: 2004
• Tongue: English
• Weight: 150 KB
• Volume: 42
• Category: Article
• ISSN: 0749-1581
• DOI: 10.1002/mrc.1321

✦ Synopsis

Abstract

Deuterated water associated with oriented POPC bilayers was investigated before and after the addition of 2 mol% peptide. Membranes in the presences of antimicrobial‐(LAH4), pore‐forming‐ (the segments M2 of influenza A and S4 of the domain I of rat brain sodium channels) or lysine‐containing model peptides (LAK1 and LAK3) were investigated by ^2^H and proton‐decoupled ^31^P solid‐state NMR. The NMR spectra were recorded as a function of hydration in the range between 15 and 93% relative humidity and of sample composition. In the presence of peptides an increased association of water is observed. A quantitative analysis suggests that the peptide‐induced changes in the lipid bilayer packing have a significant effect on membrane–water association. The quadrupolar splittings of ^2^H~2~O at a given degree of hydration indicate that the changes of the water deuterium order parameter are specific for the peptide sequence and the lipid composition. Copyright © 2004 John Wiley & Sons, Ltd.