Linked Life Data

3242950

Source:http://linkedlifedata.com/resource/pubmed/id/3242950

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3-4
pubmed:dateCreated
1989-5-26
pubmed:abstractText
A comparative study of the polymorphism exhibited by the polymerizable, tubule-forming phospholipid 1,2-bis(10,12-tricosadiynoyl)-sn-glycero-3- phosphocholine (DC23PC) and its saturated analog 1,2-ditricosanoyl-sn-glycero-3-phosphocholine (DTPC) in aqueous suspension is reported. Differential scanning calorimetry (DSC), as well as freeze-fracture electron microscopy and Raman spectroscopy, have been used to study the influence on phase behavior of rigid diacetylene groups in the fatty acyl chains of a phosphatidylcholine. DTPC large multilamellar vesicle (MLV) and small unilamellar vesicle (SUV) suspensions were found to retain liposome morphology after chain crystallization had occurred. In marked contrast, diacetylenic DC23PC suspensions do not maintain liposomal morphology in converting to the low temperature phase. Large MLVs of DC23PC with outer diameters in excess of 1 micron convert to a gel phase with cylindrical or tubular morphology at 38 degrees C, just a few degrees below the lipid's chain melting temperature (TM(H), i.e. temperature of an endothermic event observed during a heating scan) of 43.1 degrees C. Unlike the large MLVs, small MLVs or SUVs of DC23PC, with diameters of 0.4 +/- 0.3 micron and 0.04 +/- 0.02 micron, respectively, exhibit metastability in the liquid-crystalline state for several tens of degrees below the chain melting temperature prior to converting to a gel phase which, by electron microscopy, manifests itself as extended multilamellar sheets. Raman data collected at TM(H) -40 degrees C demonstrate that the gel state formed by DC23PC is very highly ordered relative to that of DTPC, suggesting that special chain packing requirements are responsible for the novel phase behavior of DC23PC.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
0009-3084
pubmed:author
pubmed:issnType
Print
pubmed:volume
48
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
215-30
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed:year
1988
pubmed:articleTitle
Differential scanning calorimetric study of the thermotropic phase behavior of a polymerizable, tubule-forming lipid.
pubmed:affiliation
Biomolecular Engineering Branch, Naval Research Laboratory, Washington, DC 20375-5000.
pubmed:publicationType
Journal Article, Comparative Study