Linked Life Data

11342156

Source:http://linkedlifedata.com/resource/pubmed/id/11342156

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1-2
pubmed:dateCreated
2001-5-8
pubmed:abstractText
Ceramides (Cers) may exert their biological activity through changes in membrane structure and organization. To understand this mechanism, the effect of Cer on the biophysical properties of phosphatidylcholine, sphingomyelin (SM) and SM/cholesterol bilayers was determined using fluorescence probe techniques. The Cers were bovine brain Cer and synthetic Cers that contained a single acyl chain species. The phospholipids were 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) and 1,2-dipalmitoyl-sn-glyero-3-phosphocholine (DPPC) and bovine brain, egg yolk and bovine erythrocyte SM. The addition of Cer to POPC and DPPC bilayers that were in the liquid-crystalline phase resulted in a linear increase in acyl chain order and decrease in membrane polarity. The addition of Cer to DPPC and SM bilayers also resulted in a linear increase in the gel to liquid-crystalline phase transition temperature (T(M)). The magnitude of the change was dependent upon Cer lipid composition and was much higher in SM bilayers than DPPC bilayers. The addition of 33 mol% cholesterol essentially eliminated the thermal transition of SM and SM/Cer bilayers. However, there is still a linear increase in acyl chain order induced by the addition of Cer. The results are interpreted as the formation of DPPC/Cer and SM/Cer lipid complexes. SM/Cer lipid complexes have higher T(M)s than the corresponding SM because the addition of Cer reduces the repulsion between the bulky headgroup and allows closer packing of the acyl chains. The biophysical properties of a SM/Cer-rich bilayer are dependent upon the amount of cholesterol present. In a cholesterol-poor membrane, a sphingomyelinase could catalyze the isothermal conversion of a liquid-crystalline SM bilayer to a gel phase SM/Cer complex at physiological temperature.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
0006-3002
pubmed:author
pubmed:issnType
Print
pubmed:day
9
pubmed:volume
1510
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
167-84
pubmed:dateRevised
2003-11-14
pubmed:meshHeading
pubmed:year
2001
pubmed:articleTitle
Interaction of ceramides with phosphatidylcholine, sphingomyelin and sphingomyelin/cholesterol bilayers.
pubmed:affiliation
Department of Medicine, Baylor College of Medicine, The Methodist Hospital, 6565 Fannin Street, M.S. A-601, Houston, TX 77030, USA. jmassey@bcm.tmc.edu
pubmed:publicationType
Journal Article