Journal Article

PreJuSER-50645

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png The phase transition behavior of 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) model membrane influenced by 2,4-dichlorophenol – an FT-Raman Spectroscopy Study

Csiszar, A.FZJ* ; Koglin, E.FZJ* ; Meier, R. ; Klumpp, E.FZJ*

2006
Elsevier Science Amsterdam [u.a.]

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Please use a persistent id in citations: doi:10.1016/j.chemphyslip.2005.11.005

Abstract: The effect of 2,4-dichlorophenol (DCP) on the structures and phase transitions of fully hydrated 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) liposomes was studied using FT-Raman spectroscopy. Whereas the Raman frequency shifts of the most frequently investigated bands of C-C and C-H stretching regions only indicate the main phase transition (P(beta')-L(alpha)) of the pure DPPC/water system, the Raman shift of C-H scissoring vibration at 1440 cm(-1) was found to be able to reveal the pretransition (L(beta')-P(beta')) as well. Analyzing the spectral parameters of the trans band at 1128 cm(-1), which does not overlap with DCP vibrational modes, a continuous decrease of trans conformations was found with increasing DCP concentration at 26 degrees C accompanying the phase transitions L(beta')-P(beta') and P(beta')-L(alpha). The intensity ratio of the symmetrical and asymmetrical methylene stretching bands (at 2850 cm(-1) and 2880 cm(-1)), defined as the disorder parameter by Levin [Levin, I.W., 1985. Two types of hydrocarbon chain interdigitation in sphingomielin bilayers. Biochemistry 24, 6282-6286], indicated that in the interdigitated phase (L(I)) the order is markedly high and comparable with that of L(beta). Both the phase transition P(beta')-L(alpha) in the DCP/DPPC molar ratio range of 10/100-50/100 and the phase transition L(I)-L(alpha) led to a significant increase of disordered chains and the presence of DCP molecules induced a more disordered chain region than that observed in the L(alpha) phase of DPPC. Nevertheless, it was found that the L(alpha) phase with DCP contains approximately the same amount of trans conformers than that without DCP.

Keyword(s): 1,2-Dipalmitoylphosphatidylcholine: chemistry (MeSH) ; Chemistry, Physical (MeSH) ; Chlorophenols: chemistry (MeSH) ; Membranes, Artificial (MeSH) ; Phase Transition (MeSH) ; Physicochemical Phenomena (MeSH) ; Sensitivity and Specificity (MeSH) ; Spectrum Analysis, Raman: methods (MeSH) ; Temperature (MeSH) ; Chlorophenols ; Membranes, Artificial ; 2,4-dichlorophenol ; 1,2-Dipalmitoylphosphatidylcholine ; J ; DPPC liposomes (auto) ; phase transitions (auto) ; FF-Raman spectroscopy (auto) ; 2.4-dichlorophenol (auto)

Note: Record converted from VDB: 12.11.2012

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Contributing Institute(s):

1. Agrosphäre (ICG-IV)
2. Biologische Schichten (ISG-4)

Research Program(s):

1. Terrestrische Umwelt (P24)
2. Kondensierte Materie (P54)

Appears in the scientific report 2006

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