Effects of physiologically relevant pressures of helium on the structure of cholesterol-containing lipid bilayers. A neutron diffraction study.
We have used neutron diffraction to study the effects of helium gas (1-210 atm) on the structure of a lipid bilayer model of neuronal plasma membranes. We have recorded diffraction patterns from hydrated multilayers of dimyristoyl lecithin and 40% (molar) cholesterol to a resolution of approximately 6.5 A and have calculated scattering amplitude density distributions as a function of pressure. We find that there are no significant changes in the scattering density profiles at 95% confidence over the range of pressures investigated, suggesting that the physiological effects of high helium pressure are unlikely to be a consequence of changes in the structures of the lipid bilayer portions of membranes.
Franks
N P
NP
Biophysics Section, Blackett Laboratory, Imperial College of Science, Technology and Medicine, London, United Kingdom.
Lieb
W R
WR
D055592:Biophysical Phenomena; D001703:Biophysics; D002784:Cholesterol / Q000737:chemistry*; D006371:Helium; D008051:Lipid Bilayers / Q000737:chemistry*; D015394:Molecular Structure; D009502:Neutrons; D011312:Pressure; D012542:Scattering, Radiation
D008051:Lipid Bilayers; D006371:Helium; D002784:Cholesterol