An antimicrobial peptide, magainin 2, induced rapid flip-flop of phospholipids coupled with pore formation and peptide translocation

Biochemistry. 1996 Sep 3;35(35):11361-8. doi: 10.1021/bi960016v.

Abstract

The effect of an antimicrobial peptide, magainin 2, on the flip-flop rates of phospholipids was investigated by use of fluorescent lipids, i.e., anionic N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl)dipalmitoyl-L-alpha- phosphatidylethanolamine (NBD-PE), 1-oleoyl-2-[12-((7-nitrobenz-2-oxa-1,3-diazol-4-yl)amino)- dodecanoyl]-L-alpha-phosphatidic acid (C12-NBD-PA), 1-oleoyl-2-[12- ((7-nitrobenz-2-oxa-1,3-diazol-4-yl)- amino)dodecanoyl]-L-alpha-phosphatidyl-L-serine (C12-NBD-PS), and zwitterionic 1-palmitoyl-2-[6-((7- nitrobenz-2-oxa-1,3-diazol-4-yl)amino)caproyl]-L-alpha-phosphatidy lcholine (C6-NBD-PC). Their intrinsic flip-flop half-lives at 30 degrees C in the absence of the peptide were 1.1 h, ca. 7 h, ca. 8 days, and > 2 days, respectively. The peptide accelerated the flip-flop half-lives of the fluorescent lipids to an order of minutes. Furthermore, the flip-flop was coupled with the membrane permeabilization and the peptide translocation [Matsuzaki, K., Murase, O., Fujii, N., & Miyajima, K. (1995) Biochemistry 34, 6521-6526], suggesting pore-mediated flip-flop. The flip-flop rate was independent of the initial labeling conditions (outer leaflet label or inner leaflet label). From these results, a model was proposed, in which the lipids translocate across the membrane by lateral diffusion along the wall of the pores composed of the peptides and the lipids. A simple theoretical calculation could explain the coupling of the flip-flop with the permeabilization.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Anti-Infective Agents / pharmacology*
  • Antimicrobial Cationic Peptides*
  • Diffusion
  • Dithionite / metabolism
  • Fluoresceins / metabolism
  • Fluorescent Dyes / metabolism
  • Kinetics
  • Lipid Bilayers / metabolism*
  • Liposomes / metabolism
  • Magainins
  • Mathematics
  • Molecular Sequence Data
  • Mutation
  • Peptides / genetics
  • Peptides / metabolism*
  • Peptides / pharmacology*
  • Permeability / drug effects
  • Phosphatidylethanolamines / metabolism
  • Phospholipids / metabolism*
  • Skin / chemistry
  • Xenopus Proteins*
  • Xenopus laevis

Substances

  • Anti-Infective Agents
  • Antimicrobial Cationic Peptides
  • Fluoresceins
  • Fluorescent Dyes
  • Lipid Bilayers
  • Liposomes
  • Magainins
  • Peptides
  • Phosphatidylethanolamines
  • Phospholipids
  • Xenopus Proteins
  • magainin 2 peptide, Xenopus
  • Dithionite
  • N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl)phosphatidylethanolamine
  • fluorexon