Linked Life Data

11023909

Source:http://linkedlifedata.com/resource/pubmed/id/11023909

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
2000-11-13
pubmed:abstractText
We have examined the effects of cholesterol on the thermotropic phase behavior and organization of aqueous dispersions of a homologous series of linear disaturated phosphatidylserines by high-sensitivity differential scanning calorimetry and Fourier transform infrared spectroscopy. We find that the incorporation of increasing quantities of cholesterol progressively reduces the temperature, enthalpy, and cooperativity of the gel-to-liquid-crystalline phase transition of the host phosphatidylserine bilayer, such that a cooperative chain-melting phase transition is completely or almost completely abolished at 50 mol % cholesterol, in contrast to the results of previous studies. We are also unable to detect the presence of a separate anhydrous cholesterol or cholesterol monohydrate phase in our binary mixtures, again in contrast to previous reports. We further show that the magnitude of the reduction in the phase transition temperature induced by cholesterol addition is independent of the hydrocarbon chain length of the phosphatidylserine studied. This result contrasts with our previous results with phosphatidylcholine bilayers, where we found that cholesterol increases or decreases the phase transition temperature in a chain length-dependent manner (1993. Biochemistry, 32:516-522), but is in agreement with our previous results for phosphatidylethanolamine bilayers, where no hydrocarbon chain length-dependent effects were observed (1999. Biochim. Biophys. Acta, 1416:119-234). However, the reduction in the phase transition temperature by cholesterol is of greater magnitude in phosphatidylethanolamine as compared to phosphatidylserine bilayers. We also show that the addition of cholesterol facilitates the formation of the lamellar crystalline phase in phosphatidylserine bilayers, as it does in phosphatidylethanolamine bilayers, whereas the formation of such phases in phosphatidylcholine bilayers is inhibited by the presence of cholesterol. We ascribe the limited miscibility of cholesterol in phosphatidylserine bilayers reported previously to a fractional crystallization of the cholesterol and phospholipid phases during the removal of organic solvent from the binary mixture before the hydration of the sample. In general, the results of our studies to date indicate that the magnitude of the effect of cholesterol on the thermotropic phase behavior of the host phospholipid bilayer, and its miscibility in phospholipid dispersions generally, depend on the strength of the attractive interactions between the polar headgroups and the hydrocarbon chains of the phospholipid molecule, and not on the charge of the polar headgroups per se.
pubmed:commentsCorrections
http://linkedlifedata.com/resource/pubmed/commentcorrection/11023909, http://linkedlifedata.com/resource/pubmed/commentcorrection/11023909-10076038, http://linkedlifedata.com/resource/pubmed/commentcorrection/11023909-10082799, http://linkedlifedata.com/resource/pubmed/commentcorrection/11023909-10216277, http://linkedlifedata.com/resource/pubmed/commentcorrection/11023909-11023908, http://linkedlifedata.com/resource/pubmed/commentcorrection/11023909-1445893, http://linkedlifedata.com/resource/pubmed/commentcorrection/11023909-1648395, http://linkedlifedata.com/resource/pubmed/commentcorrection/11023909-184844, http://linkedlifedata.com/resource/pubmed/commentcorrection/11023909-19431823, http://linkedlifedata.com/resource/pubmed/commentcorrection/11023909-19431848, http://linkedlifedata.com/resource/pubmed/commentcorrection/11023909-2302384, http://linkedlifedata.com/resource/pubmed/commentcorrection/11023909-2917161, http://linkedlifedata.com/resource/pubmed/commentcorrection/11023909-3676307, http://linkedlifedata.com/resource/pubmed/commentcorrection/11023909-3676345, http://linkedlifedata.com/resource/pubmed/commentcorrection/11023909-3689765, http://linkedlifedata.com/resource/pubmed/commentcorrection/11023909-4016068, http://linkedlifedata.com/resource/pubmed/commentcorrection/11023909-476099, http://linkedlifedata.com/resource/pubmed/commentcorrection/11023909-7669894, http://linkedlifedata.com/resource/pubmed/commentcorrection/11023909-7756552, http://linkedlifedata.com/resource/pubmed/commentcorrection/11023909-7788803, http://linkedlifedata.com/resource/pubmed/commentcorrection/11023909-8011906, http://linkedlifedata.com/resource/pubmed/commentcorrection/11023909-8422361, http://linkedlifedata.com/resource/pubmed/commentcorrection/11023909-8603092, http://linkedlifedata.com/resource/pubmed/commentcorrection/11023909-8988017, http://linkedlifedata.com/resource/pubmed/commentcorrection/11023909-9125520, http://linkedlifedata.com/resource/pubmed/commentcorrection/11023909-9889344
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
0006-3495
pubmed:author
pubmed:issnType
Print
pubmed:volume
79
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
2056-65
pubmed:dateRevised
2010-9-14
pubmed:meshHeading
pubmed:year
2000
pubmed:articleTitle
Differential scanning calorimetric and Fourier transform infrared spectroscopic studies of the effects of cholesterol on the thermotropic phase behavior and organization of a homologous series of linear saturated phosphatidylserine bilayer membranes.
pubmed:affiliation
Department of Biochemistry, University of Alberta, Edmonton, Alberta T6G 2H7, Canada.
pubmed:publicationType
Journal Article, In Vitro, Research Support, Non-U.S. Gov't