6533b7d6fe1ef96bd1266603
RESEARCH PRODUCT
Structural properties of phosphatidylcholine in a monolayer at the air/water interface
Kristian KjaerMathias LöscheJens Aage Als-nielsenDavid Vakninsubject
CrystallographyLangmuirReflection (mathematics)ChemistryPhase (matter)X-ray crystallographyMomentum transferMonolayerAnalytical chemistryBiophysicsNeutronReflectometrydescription
Neutron reflectivities of phosphatidylcholine monolayers in the liquid condensed (LC) phase on ultrapure H 2 O and D 2 O 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 Q z = 0–0.4A -1 were accessed. In a new approach, by refining neutron reflectivity data from chain-perdeuterated DPPC-d 62 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 L β , 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.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 1991-06-01 | Biophysical Journal |