Abstract
We present applied osmotic pressure vs. distance curves constructed from high-resolution neutron and X-ray diffraction scattering density profiles of dipalmitoyl phosphatidylcholine (DPPC) multibilayers in the gel Lβ′ phase. The data, obtained from three distinct regions of the lipid bilayer, show that at small interbilayer distances the repulsion observed in these bilayers can be accounted for by the so-called "hydration force". Also, a previous observation of a sharp upward break in the pressure-distance curve of highly ordered Lc′ DPPC bilayers is not the result of steric repulsion but rather of a 2D → 3D phase transition. The data are consistent with a recent theoretical model which predicts that the repulsive forces in ordered phases (e.g., Lβ′ and Lc′ phases) are dominated by the hydration force.
Original language | English |
---|---|
Pages (from-to) | 43-48 |
Number of pages | 6 |
Journal | EPL |
Volume | 38 |
Issue number | 1 |
DOIs | |
State | Published - Apr 1 1997 |
Externally published | Yes |