Packing of ganglioside-phospholipid monolayers: An X-ray diffraction and reflectivity study

J. Majewski, T.L. Kuhl, K. Kjær, G.S. Smith

    Research output: Contribution to journalJournal articleResearchpeer-review


    Using synchrotron grazing-incidence x-ray diffraction (GIXD) and reflectivity, the in-plane and out-of-plane structure of mixed ganglioside-phospholipid monolayers was investigated at the air-water interface. Mixed monolayers of 0, 5, 10, 20, and 100 mol% ganglioside GM, and the phospholipid dipaimitoylphosphatidylethanolamine (DPPE) were studied in the solid phase at 23 degreesC and a surface pressure of 45 mN/m. At these concentrations and conditions the two components do not phase-separate and no evidence for domain formation was observed. X-ray scattering measurements reveal that GM, is accommodated within the host DPPE monolayer and does not distort the hexagonal in-plane unit cell or out-of-plane two-dimensional (2-D) packing compared with a pure DPPE monolayer. The oligosaccharide headgroups were found to extend normally from the monolayer surface, and the incorporation of these glycolipids into DPPE monolayers did not affect hydrocarbon tail packing (fluidization or condensation of the hydrocarbon region). This is in contrast to previous investigations of lipopolymer-lipid mixtures, where the packing structure of phospholipid monolayers was greatly altered by the inclusion of lipids bearing hydrophilic polymer groups. Indeed, the lack of packing disruptions by the oligosaccharide groups indicates that protein-GM, interactions, including binding, insertion, chain fluidization, and domain formation (lipid rafts), can be studied in 2-D monolayers using scattering techniques.
    Original languageEnglish
    JournalBiophysical Journal
    Issue number5
    Pages (from-to)2707-2715
    Publication statusPublished - 2001


    Dive into the research topics of 'Packing of ganglioside-phospholipid monolayers: An X-ray diffraction and reflectivity study'. Together they form a unique fingerprint.

    Cite this