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| Predicate | Object |
|---|---|
| rdf:type | |
| lifeskim:mentions | |
| pubmed:issue |
23
|
| pubmed:dateCreated |
1987-3-16
|
| pubmed:abstractText |
By use of neutron diffraction, the structural parameters of oriented multilayers of 1,2-dimyristoyl-sn-glycero-3-phosphatidylcholine with deuteriocarbon chains/cholesterol (molar ratio 70:30), multilamellar lipid vesicles composed of pure lipids and lipid/cholesterol mixtures, and crystalline purple membrane patches from Halobacterium halobium have been measured at pressures up to 2 kbar. Pressurization of the oriented 1,2-dimyristoyl-sn-glycero-3-phosphatidylcholine/cholesterol multilayers results in an in-plane compression with the mean deuteriocarbon chain spacing of 4.44 A obtained under ambient conditions decreasing by 3-7% at 1.9 kbar. The thickness for this bilayer increases by approximately equal to 1.5 A, but the net bilayer volume decreases and the isothermal compressibility is estimated to be in the range (-0.1 to -0.6) X 10(-4)/bar at 19.0 degrees C. The d spacings for multilamellar vesicles composed of lipids in the liquid crystalline state and lipid/cholesterol mixtures increase linearly as a function of pressure, suggesting that these bilayers are also compressed in the membrane plane. For 1,2-dipalmitoyl-sn-glycero-3-phosphatidylcholine and 1,2-distearoyl-sn-glycero-3-phosphatidylcholine MLVs in the gel state, the d spacing decreases with pressure. For 1,2-dipalmitoyl-sn-glycero-3-phosphatidylcholine, the hexagonally packed chains are anisotropically compressed in the bilayer plane, resulting in a pseudohexagonal chain packing at 1.9 kbar. The bilayer compressibility is (-0.4 or -0.5) X 10(-4)/bar depending on whether the chain tilt increases with pressure or terminal methyl groups of apposing lipid monolayers approach each other.(ABSTRACT TRUNCATED AT 250 WORDS)
|
| pubmed:language |
eng
|
| pubmed:journal | |
| pubmed:citationSubset |
IM
|
| pubmed:chemical | |
| pubmed:status |
MEDLINE
|
| pubmed:month |
Nov
|
| pubmed:issn |
0006-2960
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| pubmed:author | |
| pubmed:issnType |
Print
|
| pubmed:day |
18
|
| pubmed:volume |
25
|
| pubmed:owner |
NLM
|
| pubmed:authorsComplete |
Y
|
| pubmed:pagination |
7484-8
|
| pubmed:dateRevised |
2001-11-2
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| pubmed:meshHeading |
pubmed-meshheading:3801427-Bacteriorhodopsins,
pubmed-meshheading:3801427-Deuterium,
pubmed-meshheading:3801427-Halobacterium,
pubmed-meshheading:3801427-Hydrostatic Pressure,
pubmed-meshheading:3801427-Lipid Bilayers,
pubmed-meshheading:3801427-Models, Biological,
pubmed-meshheading:3801427-Molecular Conformation,
pubmed-meshheading:3801427-Phosphatidylcholines
|
| pubmed:year |
1986
|
| pubmed:articleTitle |
Structural changes in lipid bilayers and biological membranes caused hydrostatic pressure.
|
| pubmed:publicationType |
Journal Article
|