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Predicate | Object |
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rdf:type | |
lifeskim:mentions | |
pubmed:issue |
38
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pubmed:dateCreated |
1993-11-2
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pubmed:abstractText |
Endonexin (annexin IV) is a member of the annexin family of homologous proteins that share the ability to bind to pure lipid membranes and to aggregate vesicles in a Ca(2+)-dependent fashion. Endonexin appears to preferentially interact with certain types of lipids such as phosphatidylglycerol (PG) in PG/phosphatidylcholine (PC) mixed lipid membranes. Such preferential binding should result in localization of PG lipids to membrane regions where endonexin is bound. This was tested using a PG derivative containing the fluorophore pyrene, which exhibits fluorescence sensitive to molecular collision frequency. Motional restriction of pyrene-PG upon endonexin-membrane binding was evident from decreased ratios of excimer-to-monomer (E/M) pyrene fluorescence with endonexin binding to 97% PG/3% pyrene-PG vesicles. A maximum decrease of 30% suggests a 30% decrease in the average diffusion constant of pyrene-PG molecules or a 53% decrease assuming that only outer-monolayer lipid molecules interact with endonexin. In vesicles containing 5% and 10% pyrene-PG in PC, segregation of lipids was evident from observed increases in E/M of 14.2 +/- 1.8% and 6.8 +/- 0.1%, respectively, in the presence of endonexin and either 10 mM (5% pyrene-PG) or 2 mM (10% pyrene-PG) free Ca2+. At higher concentrations of Ca2+ (> 10 mM for 5% pyrene-PG and > 2 mM for 10% pyrene-PG), smaller endonexin-dependent increases in E/M are observed as endonexin molecules at high surface densities compete for the limited pool of pyrene-PG. The nature of these interactions of endonexin with mixed lipid systems has implications for the way annexins may modulate membrane structure in cells.
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pubmed:language |
eng
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pubmed:journal | |
pubmed:citationSubset |
IM
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pubmed:chemical |
http://linkedlifedata.com/resource/pubmed/chemical/Annexin A4,
http://linkedlifedata.com/resource/pubmed/chemical/Calcium,
http://linkedlifedata.com/resource/pubmed/chemical/Liposomes,
http://linkedlifedata.com/resource/pubmed/chemical/Phosphatidylcholines,
http://linkedlifedata.com/resource/pubmed/chemical/Phosphatidylglycerols,
http://linkedlifedata.com/resource/pubmed/chemical/Pyrenes
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pubmed:status |
MEDLINE
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pubmed:month |
Sep
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pubmed:issn |
0006-2960
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pubmed:author | |
pubmed:issnType |
Print
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pubmed:day |
28
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pubmed:volume |
32
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
9968-74
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pubmed:dateRevised |
2006-11-15
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pubmed:meshHeading |
pubmed-meshheading:8399166-Animals,
pubmed-meshheading:8399166-Annexin A4,
pubmed-meshheading:8399166-Calcium,
pubmed-meshheading:8399166-Cattle,
pubmed-meshheading:8399166-Kinetics,
pubmed-meshheading:8399166-Liposomes,
pubmed-meshheading:8399166-Liver,
pubmed-meshheading:8399166-Phosphatidylcholines,
pubmed-meshheading:8399166-Phosphatidylglycerols,
pubmed-meshheading:8399166-Protein Binding,
pubmed-meshheading:8399166-Pyrenes,
pubmed-meshheading:8399166-Spectrometry, Fluorescence
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pubmed:year |
1993
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pubmed:articleTitle |
Endonexin (annexin IV)-mediated lateral segregation of phosphatidylglycerol in phosphatidylglycerol/phosphatidylcholine membranes.
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pubmed:affiliation |
Program in Biophysics, University of Virginia, Charlottesville 22908.
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pubmed:publicationType |
Journal Article,
Research Support, U.S. Gov't, P.H.S.
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