Interactions of an antimicrobial peptide, magainin 2, with lipopolysaccharide-containing liposomes as a model for outer membranes of gram-negative bacteria.
F12W-magainin 2 preferentially interacted with lipopolysaccharide-containing bilayers, permeabilizing the membranes, compared with lipopolysaccharide-free phosphatidylcholine vesicles. Using this system, we demonstrated for the first time that the magainin peptide forms a helix upon binding to lipopolysaccharide. Incorporation of lipid A into phosphatidylcholine liposomes also enhanced interactions with the peptide. The presence of Mg2+, which nullifies the peptide's antibacterial activity against gram-negative bacteria, again weakened the interactions between the peptide and lipopolysaccharide-doped bilayers. This system seems to be useful for investigating the molecular details of peptide-lipopolysaccharide interactions.
Matsuzaki
K
K
Graduate School of Pharmaceutical Sciences, Kyoto University, Japan. katsumim@pharm.kyoto-u.ac.jp
Sugishita
K
K
Miyajima
K
K
D000595:Amino Acid Sequence; D000818:Animals; D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000378:metabolism*; D023181:Antimicrobial Cationic Peptides; D001425:Bacterial Outer Membrane Proteins / Q000378:metabolism*; D002942:Circular Dichroism; D004926:Escherichia coli / Q000378:metabolism; D006090:Gram-Negative Bacteria / Q000378:metabolism*; D008050:Lipid A / Q000378:metabolism; D008070:Lipopolysaccharides / Q000378:metabolism*; D008081:Liposomes; D054806:Magainins; D008274:Magnesium; D008954:Models, Biological; D008969:Molecular Sequence Data; D010455:Peptides / Q000737:chemistry / Q000378:metabolism*; D010713:Phosphatidylcholines / Q000378:metabolism*; D029867:Xenopus Proteins; D014982:Xenopus laevis
D000900:Anti-Bacterial Agents; D023181:Antimicrobial Cationic Peptides; D001425:Bacterial Outer Membrane Proteins; D008050:Lipid A; D008070:Lipopolysaccharides; D008081:Liposomes; D054806:Magainins; D010455:Peptides; D010713:Phosphatidylcholines; D029867:Xenopus Proteins; C053301:magainin 2 peptide, Xenopus; D008274:Magnesium