The Journal of Membrane Biology

, Volume 167, Issue 3, pp 241–249

Lipid-Induced Organization of a Primary Amphipathic Peptide: A Coupled AFM-Monolayer Study

  • N.  Van Mau
  • V.  Vié
  • L.  Chaloin
  • E.  Lesniewska
  • F.  Heitz
  • C.  Le Grimellec

DOI: 10.1007/s002329900488

Cite this article as:
Van Mau, N., Vié, V., Chaloin, L. et al. J. Membrane Biol. (1999) 167: 241. doi:10.1007/s002329900488

Abstract.

To better understand the nature of the mechanism involved in the membrane uptake of a vector peptide, the interactions between dioleoylphosphatidylcholine and a primary amphipathic peptide containing a signal peptide associated with a nuclear localization sequence have been studied by isotherms analysis of mixed monolayers spread at the air-water interface. The peptide and the lipid interact through strong hydrophobic interactions with expansion of the mean molecular area that resulted from a lipid-induced modification of the organization of the peptide at the interface. In addition, a phase separation occurs for peptide molar fraction ranging from about 0.08 to 0.4 Atomic force microscopy observations made on transferred monolayers confirm the existence of phase separation and further reveal that mixed lipid-peptide particles are formed, the size and shape of which depend on the peptide molar fraction. At low peptide contents, round-shaped particles are observed and an increase of the peptide amount, simultaneously to the lipidic phase separation, induces morphological changes from bowls to filamentous particles. Fourier transform infrared spectra (FTIR) obtained on transferred monolayers indicate that the peptide adopts a β-like structure for high peptide molar fractions. Such an approach involving complementary methods allows us to conclude that the lipid and the peptide have a nonideal miscibility and form mixed particles which phase separate.

Key words: AFM — Mixed monolayers — Langmuir-Blodgett films — Lipid-peptide interactions 

Copyright information

© 1999 Springer-Verlag New York Inc.

Authors and Affiliations

  • N.  Van Mau
    • 1
  • V.  Vié
    • 2
  • L.  Chaloin
    • 1
  • E.  Lesniewska
    • 3
  • F.  Heitz
    • 1
  • C.  Le Grimellec
    • 2
  1. 1.CRBM, CNRS-UPR 1086, 1919 route de Mende, 34293 Montpellier Cedex 5, FranceFR
  2. 2.CBS, INSERM-U414, IURC, 75 rue de la Cardonille, 34093 Montpellier Cedex 5, FranceFR
  3. 3.Laboratoire de Physique, CNRS-URA 5027, UFR Sciences et Techniques, 9 rue Alain Savary, B.P. 400, 21011 Dijon Cedex, FranceFR

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