Peptide-related alterations of membrane-associated water: deuterium solid-state NMR investigations of phosphatidylcholine membranes at different hydration levels.
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.
Moraes
Cléria Mendonça
CM
Faculté de Chimie, Institut le Bel, 4 rue Blaise Pascal, 67070 Strasbourg, France.
Bechinger
Burkhard
B
D000595:Amino Acid Sequence; D000818:Animals; D001921:Brain / Q000502:physiology; D003903:Deuterium; D008081:Liposomes / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D008567:Membranes, Artificial; D008969:Molecular Sequence Data; D009419:Nerve Tissue Proteins / Q000737:chemistry; D010455:Peptides / Q000737:chemistry*; D010713:Phosphatidylcholines / Q000737:chemistry*; D011487:Protein Conformation; D051381:Rats; D015222:Sodium Channels / Q000737:chemistry / Q000502:physiology; D014867:Water
D008081:Liposomes; D008567:Membranes, Artificial; D009419:Nerve Tissue Proteins; D010455:Peptides; D010713:Phosphatidylcholines; D015222:Sodium Channels; D014867:Water; D003903:Deuterium; C028694:1-palmitoyl-2-oleoylphosphatidylcholine