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. 1991 Jun;59(6):1325–1332. doi: 10.1016/S0006-3495(91)82347-5

Structural properties of phosphatidylcholine in a monolayer at the air/water interface

Neutron reflection study and reexamination of x-ray reflection measurements

David Vaknin *, Kristian Kjaer *, Jens Als-Nielsen *, Mathias Lösche ‡
PMCID: PMC1281212  PMID: 19431794

Abstract

Neutron reflectivities of phosphatidylcholine monolayers in the liquid condensed (LC) phase on ultrapure H2O and D2O subphases have been measured on a Langmuir film balance. Using a dedicated liquid surface reflectometer, reflectivities down to R = 10-6 in the momentum transfer range Qz = 0-0.4 Å-1 were accessed.

In a new approach, by refining neutron reflectivity data from chain-perdeuterated DPPC-d62 in combination with x-ray measurements on the same monolayer under similar conditions it is shown that the two techniques mutually complement one another. This analysis leads to a detailed conception of the interface structure. It is found that in the LC phase (which is analogous to the Lβ, phase in vesicle dispersions) the head group is interpenetrated with subphase water (4 ± 2.5 molecules per lipid) and the average tilt angle of the hydrophobic chains from the surface normal is 33 ± 3 degrees.

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Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. Bayerl T. M., Thomas R. K., Penfold J., Rennie A., Sackmann E. Specular reflection of neutrons at phospholipid monolayers. Changes of monolayer structure and headgroup hydration at the transition from the expanded to the condensed phase state. Biophys J. 1990 May;57(5):1095–1098. doi: 10.1016/S0006-3495(90)82628-X. [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. Büldt G., Gally H. U., Seelig J., Zaccai G. Neutron diffraction studies on phosphatidylcholine model membranes. I. Head group conformation. J Mol Biol. 1979 Nov 15;134(4):673–691. doi: 10.1016/0022-2836(79)90479-0. [DOI] [PubMed] [Google Scholar]
  3. Hui S. W., Cowden M., Papahadjopoulos D., Parsons D. F. Electron diffraction study of hydrated phospholipid single bilayers. Effects of temperature hydration and surface pressure of the "precursor" monolayer. Biochim Biophys Acta. 1975 Mar 25;382(3):265–275. doi: 10.1016/0005-2736(75)90269-2. [DOI] [PubMed] [Google Scholar]
  4. King G. I., White S. H. Determining bilayer hydrocarbon thickness from neutron diffraction measurements using strip-function models. Biophys J. 1986 May;49(5):1047–1054. doi: 10.1016/S0006-3495(86)83733-X. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. Lis L. J., McAlister M., Fuller N., Rand R. P., Parsegian V. A. Interactions between neutral phospholipid bilayer membranes. Biophys J. 1982 Mar;37(3):657–665. [PMC free article] [PubMed] [Google Scholar]
  6. Marcelja S. Chain ordering in liquid crystals. II. Structure of bilayer membranes. Biochim Biophys Acta. 1974 Oct 29;367(2):165–176. doi: 10.1016/0005-2736(74)90040-6. [DOI] [PubMed] [Google Scholar]
  7. McIntosh T. J., Magid A. D., Simon S. A. Range of the solvation pressure between lipid membranes: dependence on the packing density of solvent molecules. Biochemistry. 1989 Sep 19;28(19):7904–7912. doi: 10.1021/bi00445a053. [DOI] [PubMed] [Google Scholar]
  8. McIntosh T. J., Simon S. A. Area per molecule and distribution of water in fully hydrated dilauroylphosphatidylethanolamine bilayers. Biochemistry. 1986 Aug 26;25(17):4948–4952. doi: 10.1021/bi00365a034. [DOI] [PubMed] [Google Scholar]
  9. Nagle J. F., Wiener M. C. Relations for lipid bilayers. Connection of electron density profiles to other structural quantities. Biophys J. 1989 Feb;55(2):309–313. doi: 10.1016/S0006-3495(89)82806-1. [DOI] [PMC free article] [PubMed] [Google Scholar]
  10. Oldani D., Hauser H., Nichols B. W., Phillips M. C. Monolayer characteristics of some glycolipids at the air-water interface. Biochim Biophys Acta. 1975 Feb 28;382(1):1–9. doi: 10.1016/0005-2736(75)90366-1. [DOI] [PubMed] [Google Scholar]
  11. Parsegian V. A., Fuller N., Rand R. P. Measured work of deformation and repulsion of lecithin bilayers. Proc Natl Acad Sci U S A. 1979 Jun;76(6):2750–2754. doi: 10.1073/pnas.76.6.2750. [DOI] [PMC free article] [PubMed] [Google Scholar]
  12. Wiener M. C., Suter R. M., Nagle J. F. Structure of the fully hydrated gel phase of dipalmitoylphosphatidylcholine. Biophys J. 1989 Feb;55(2):315–325. doi: 10.1016/S0006-3495(89)82807-3. [DOI] [PMC free article] [PubMed] [Google Scholar]
  13. Wiener M. C., Tristram-Nagle S., Wilkinson D. A., Campbell L. E., Nagle J. F. Specific volumes of lipids in fully hydrated bilayer dispersions. Biochim Biophys Acta. 1988 Feb 18;938(2):135–142. doi: 10.1016/0005-2736(88)90153-8. [DOI] [PubMed] [Google Scholar]
  14. Wiener M. C., White S. H. Fluid bilayer structure determination by the combined use of x-ray and neutron diffraction. II. "Composition-space" refinement method. Biophys J. 1991 Jan;59(1):174–185. doi: 10.1016/S0006-3495(91)82209-3. [DOI] [PMC free article] [PubMed] [Google Scholar]
  15. Zaccai G., Büldt G., Seelig A., Seelig J. Neutron diffraction studies on phosphatidylcholine model membranes. II. Chain conformation and segmental disorder. J Mol Biol. 1979 Nov 15;134(4):693–706. doi: 10.1016/0022-2836(79)90480-7. [DOI] [PubMed] [Google Scholar]

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