High-pressure small-angle neutron scattering (SANS) study of 1,2-dielaidoyl-sn-glycero-3-phosphocholine bilayers.
Small-angle neutron scattering of the trans-unsaturated DEPC has been investigated as a function of pressure at 12, 18.6 and 35 degrees C. A pressure-induced structural phase transition from a liquid-crystalline state to a gel state is observed at the temperatures studied. The critical pressure of this transition increases with increasing temperature with a delta P/delta T value of 51 bar/C degrees. The small-angle neutron scattering results indicate that the effect of the trans double bonds in DEPC is to enhance the conformational disorder in the hydrocarbon chains. In DEPC bilayers, a pressure-induced conformational ordering process is observed not only in the liquid-crystalline phase but also in the gel phase, which indicates that conformational disorder exists in the liquid-crystalline phase as well as in the gel phase.
Winter
R
R
Institute of Physical Chemistry, Philipps-University of Marburg, F.R.G.
Xie
C L
CL
Jonas
J
J
Thiyagarajan
P
P
Wong
P T
PT
D005231:Fatty Acids, Unsaturated; D005782:Gels; D008051:Lipid Bilayers; D008968:Molecular Conformation; D009502:Neutrons; D010713:Phosphatidylcholines; D012542:Scattering, Radiation; D013696:Temperature
D005231:Fatty Acids, Unsaturated; D005782:Gels; D008051:Lipid Bilayers; D010713:Phosphatidylcholines