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rdf:type | |
lifeskim:mentions | |
pubmed:issue |
47
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pubmed:dateCreated |
1991-2-28
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pubmed:abstractText |
The influence of cholesterol on the phase behavior of glycerophospholipids and sphingomyelins was investigated by spin-label electron spin resonance (ESR) spectroscopy. 4-(4,4-Dimethyl-3-oxy-2-tridecyl-2-oxazolidinyl)butanoic acid (5-SASL) and 1-stearoyl-2-[4-(4,4-dimethyl-3-oxy-2-tridecyl-2-oxazolidinyl)butanoy l]-sn- glycero-3-phosphocholine (5-PCSL) spin-labels were employed for this purpose. The outer hyperfine splitting constants, Amax, measured from the spin-label ESR spectra as a function of temperature were taken as empirical indicators of cholesterol-induced changes in the acyl chain motions in the fluid state. The Amax values of 5-PCSL exhibit a triphasic dependence on the concentration of cholesterol for phosphatidylcholines and bovine brain sphingomyelin. We interpret this dependence as reflecting the existence of liquid-disordered, ld, liquid-ordered, lo, and coexistence regions, ld + lo. The phase boundary between the ld and the two-phase region and the boundary between the lo and the two-phase region in the phosphatidylcholine-cholesterol systems coalesce at temperatures 25-33 degrees C above the main-chain melting transition temperature of the cholesterol-free phosphatidylcholine bilayers. In the case of bovine brain sphingomyelin, the ld-lo phase coalescence occurs about 47 degrees C above the melting temperature of the pure sphingomyelin. The selectivity of interaction of cholesterol with glycerophospholipids of varying headgroup charge was studied by comparing the cholesterol-induced changes in the Amax values of derivatives of phosphatidylcholine, phosphatidic acid, phosphatidylethanolamine, phosphatidylglycerol, and phosphatidylserine spin-labeled at the fifth position of the sn-2 chain.(ABSTRACT TRUNCATED AT 250 WORDS)
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pubmed:grant | |
pubmed:language |
eng
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pubmed:journal | |
pubmed:citationSubset |
IM
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pubmed:chemical |
http://linkedlifedata.com/resource/pubmed/chemical/Cholesterol,
http://linkedlifedata.com/resource/pubmed/chemical/Phosphatidic Acids,
http://linkedlifedata.com/resource/pubmed/chemical/Phosphatidylcholines,
http://linkedlifedata.com/resource/pubmed/chemical/Sphingomyelins,
http://linkedlifedata.com/resource/pubmed/chemical/Spin Labels
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pubmed:status |
MEDLINE
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pubmed:month |
Nov
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pubmed:issn |
0006-2960
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pubmed:author | |
pubmed:issnType |
Print
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pubmed:day |
27
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pubmed:volume |
29
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
10670-5
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pubmed:dateRevised |
2007-11-14
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pubmed:meshHeading |
pubmed-meshheading:2176878-Cholesterol,
pubmed-meshheading:2176878-Electron Spin Resonance Spectroscopy,
pubmed-meshheading:2176878-Membrane Fluidity,
pubmed-meshheading:2176878-Phosphatidic Acids,
pubmed-meshheading:2176878-Phosphatidylcholines,
pubmed-meshheading:2176878-Sphingomyelins,
pubmed-meshheading:2176878-Spin Labels
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pubmed:year |
1990
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pubmed:articleTitle |
Interaction of cholesterol with various glycerophospholipids and sphingomyelin.
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pubmed:affiliation |
Department of Biochemistry, University of Virginia Health Sciences Center, Charlottesville 22908.
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pubmed:publicationType |
Journal Article,
Research Support, U.S. Gov't, P.H.S.
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