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Predicate | Object |
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rdf:type | |
lifeskim:mentions |
umls-concept:C0008377,
umls-concept:C0024485,
umls-concept:C0028580,
umls-concept:C0031676,
umls-concept:C0337112,
umls-concept:C1373200,
umls-concept:C1524075,
umls-concept:C1546465,
umls-concept:C1705175,
umls-concept:C1705176,
umls-concept:C1705177,
umls-concept:C1705178,
umls-concept:C1709059,
umls-concept:C1882348
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pubmed:issue |
47
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pubmed:dateCreated |
1991-2-28
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pubmed:abstractText |
The effect of cholesterol on the acyl chain order of three glycerophosphocholines with 14, 16, and 18 carbons per acyl chain, namely, di(14:0)PC, di(16:0)PC, and di(18:0)PC, above the gel to liquid-crystalline phase transition temperature was investigated by using 2H nuclear magnetic resonance spectroscopy. Average acyl chain lengths were calculated from the segmental order parameters (Smol) for the sn-1 and the sn-2 chains in the absence of cholesterol and at 3:1, 2:1, and 1:1 mole ratios of phospholipid-cholesterol. The three binary mixtures of cholesterol with phosphatidylcholines are in the liquid-ordered (lo) phase. For all the three phosphatidylcholine-cholesterol systems, the distance from the carbonyl groups to the terminal methyl groups is shorter than the length of the cholesterol molecule. A molecular model for the lo phase consistent with these observations has in a statistical sense a part of each cholesterol molecule in one monolayer extending into the other monolayer. This results in a packing arrangement akin to that in interdigitated systems. On the basis of the effect of cholesterol on phospholipid acyl chain orientational order, it is suggested that the liquid-disordered (ld) phase at low cholesterol concentrations corresponds to a packing mode in which the cholesterol molecule spans the entire transbilayer hydrophobic region. A molecular mechanism is proposed in which increasing the concentration of cholesterol has the effect of stretching the acyl chains of phospholipids by increasing the population of trans conformers up to a stage where the hydrophobic length is considerably longer than the cholesterol molecule. Beyond this concentration, the partially interdigitated phase forms.(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/1,2-distearoyllecithin,
http://linkedlifedata.com/resource/pubmed/chemical/Acetic Acid,
http://linkedlifedata.com/resource/pubmed/chemical/Acetic Acids,
http://linkedlifedata.com/resource/pubmed/chemical/Cholesterol,
http://linkedlifedata.com/resource/pubmed/chemical/Deuterium,
http://linkedlifedata.com/resource/pubmed/chemical/Dimyristoylphosphatidylcholine,
http://linkedlifedata.com/resource/pubmed/chemical/Lithium,
http://linkedlifedata.com/resource/pubmed/chemical/Membranes, Artificial,
http://linkedlifedata.com/resource/pubmed/chemical/Phosphatidylcholines
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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 |
10676-84
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pubmed:dateRevised |
2007-11-14
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pubmed:meshHeading |
pubmed-meshheading:2271675-Acetic Acid,
pubmed-meshheading:2271675-Acetic Acids,
pubmed-meshheading:2271675-Cholesterol,
pubmed-meshheading:2271675-Deuterium,
pubmed-meshheading:2271675-Dimyristoylphosphatidylcholine,
pubmed-meshheading:2271675-Lithium,
pubmed-meshheading:2271675-Magnetic Resonance Spectroscopy,
pubmed-meshheading:2271675-Membrane Fluidity,
pubmed-meshheading:2271675-Membranes, Artificial,
pubmed-meshheading:2271675-Models, Chemical,
pubmed-meshheading:2271675-Phosphatidylcholines,
pubmed-meshheading:2271675-Thermodynamics
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pubmed:year |
1990
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pubmed:articleTitle |
Modulation of phospholipid acyl chain order by cholesterol. A solid-state 2H nuclear magnetic resonance study.
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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,
Comparative Study,
Research Support, U.S. Gov't, P.H.S.
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