Effect of 2,4-dichlorophenol on DPPC/water liposomes studied by X-ray and freeze-fracture electron microscopy.
The effect of 2,4-dichlorophenol (DCP) was studied on the fully hydrated 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC)--water liposomes. The structure and the thermotropic phase behaviour of the liposomes was examined in the presence of DCP (DCP/DPPC molar ratio, varied from 2x10(-2) up to 1) using small- and wide-angle X-ray scattering (SAXS, WAXS) and freeze-fracture electron microscopy. The structural behaviour of the DPPC/DCP/water system was strongly dependent on the concentration of the DCP. In the pretransition range the DCP molecules (at 2x10(-2) DCP/DPPC molar ratio) induced the interdigitated phase beside the parent (gel and rippled gel) phases, locally which can be form at higher DCP concentration. When the DCP/DPPC molar ratio was increased the pretransition disappeared and the main transition was shifted to lower temperatures. In the molar ratio range from 2x10(-1) up to 5x10(-1), a coexistence of different phases was observed in the wide temperature range from 20 up to 40 degrees C. With a further increase of the DCP/DPPC molar ratio (6x10(-1) to 1) only the interdigitated gel phase occurred below 25 degrees C. A schematic phase diagram of DPPC/DCP/water system was constructed to summarise the results.
Csiszár
Agnes
A
Institute of Agrosphere, Research Centre Julich, D-52428 Julich, Germany.
Klumpp
Erwin
E
Bóta
Attila
A
Szegedi
Krisztián
K
D015060:1,2-Dipalmitoylphosphatidylcholine / Q000737:chemistry*; D002733:Chlorophenols / Q000737:chemistry*; D005614:Freeze Fracturing; D008081:Liposomes / Q000737:chemistry*; D008854:Microscopy, Electron / Q000379:methods; D016011:Normal Distribution; D044367:Phase Transition; D014867:Water / Q000737:chemistry*; D014961:X-Ray Diffraction
D002733:Chlorophenols; D008081:Liposomes; D014867:Water; D015060:1,2-Dipalmitoylphosphatidylcholine; C004762:2,4-dichlorophenol