title: Amphipathic antimicrobial piscidin in magnetically aligned lipid bilayers.
abstract: The amphipathic antimicrobial peptide piscidin 1 was studied in magnetically aligned phospholipid bilayers by oriented-sample solid-state NMR spectroscopy. (31)P NMR and double-resonance (1)H/(15)N NMR experiments performed between 25 °C and 61 °C enabled the lipid headgroups as well as the peptide amide sites to be monitored over a range of temperatures. The α-helical peptide dramatically affects the phase behavior and structure of anionic bilayers but not those of zwitterionic bilayers. Piscidin 1 stabilizes anionic bilayers, which remain well aligned up to 61 °C when piscidin 1 is on the membrane surface. Two-dimensional separated-local-field experiments show that the tilt angle of the peptide is 80 ± 5°, in agreement with previous results on mechanically aligned bilayers. The peptide undergoes fast rotational diffusion about the bilayer normal under these conditions, and these studies demonstrate that magnetically aligned bilayers are well suited for structural studies of amphipathic peptides.
authors: Department of Chemistry and Biochemistry, University of California at San Diego, La Jolla, California, USA.
authors: Anna A
authors: AA
authors: De Angelis
authors: Christopher V
authors: CV
authors: Grant
authors: Matthew K
authors: MK
authors: Baxter
authors: Jason A
authors: JA
authors: McGavin
authors: Stanley J
authors: SJ
authors: Opella
authors: Myriam L
authors: ML
authors: Cotten
mesh_terms: D000595:Amino Acid Sequence; D023181:Antimicrobial Cationic Peptides / Q000737:chemistry* / Q000378:metabolism; D005240:Feasibility Studies; D029941:Fish Proteins / Q000737:chemistry* / Q000378:metabolism; D057927:Hydrophobic and Hydrophilic Interactions; D008051:Lipid Bilayers / Q000737:chemistry* / Q000378:metabolism; D060328:Magnetic Phenomena; D009682:Magnetic Resonance Spectroscopy; D008969:Molecular Sequence Data; D017433:Protein Structure, Secondary; D013696:Temperature
chemical_list: D023181:Antimicrobial Cationic Peptides; D029941:Fish Proteins; D008051:Lipid Bilayers; C449802:moronecidin protein, Morone saxatilis