Thermal unbinding of highly oriented phospholipid membranes.
We present a temperature dependent x-ray reflectivity study of highly oriented, fully hydrated multilamellar phospholipid membranes. Both the specular and diffuse (nonspecular) x-ray reflectivity were measured for dimyristoyl-sn-glycero-phosphocholine (DMPC) and oleoyl-palmitoyl-sn-glycero-phosphocholine (POPC) on silicon substrates in excess water. In this configuration the repeat distance as well as the fluctuation spectra can be determined as a function of temperature. Both model systems studied exhibit a discontinuous unbinding transition from a substrate bound, multilamellar state to a state of freely dispersed bilayers in water. In the unbound phase a single membrane remains on the substrate.
Vogel
M
M
Sektion Physik der Ludwig-Maximilians-Universität München, Geschwister-Scholl-Platz 1, D-80539 München, Germany.
Münster
C
C
Fenzl
W
W
Salditt
T
T
D004134:Dimyristoylphosphatidylcholine / Q000737:chemistry / Q000378:metabolism; D008051:Lipid Bilayers / Q000737:chemistry* / Q000378:metabolism*; D010713:Phosphatidylcholines / Q000737:chemistry / Q000378:metabolism; D010743:Phospholipids / Q000737:chemistry* / Q000378:metabolism*; D012542:Scattering, Radiation; D012825:Silicon; D013696:Temperature; D013816:Thermodynamics; D014867:Water / Q000378:metabolism; D014965:X-Rays
D008051:Lipid Bilayers; D010713:Phosphatidylcholines; D010743:Phospholipids; D014867:Water; C028694:1-palmitoyl-2-oleoylphosphatidylcholine; D004134:Dimyristoylphosphatidylcholine; D012825:Silicon