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Predicate | Object |
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rdf:type | |
lifeskim:mentions | |
pubmed:issue |
2
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pubmed:dateCreated |
1985-7-24
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pubmed:abstractText |
Binding of heparin and low molecular weight heparin fragments (CY 222, Mr range 1500-8000) to human vascular endothelial cells was studied. Primary culture of human umbilical vein endothelial cells and either 125I or 3H-labeled heparin or [125I]CY 222 were used. Slow, saturable and specific binding was found. No other tested glycosaminoglycan, excepting a highly sulfated heparan fraction, was able to compete for heparin binding. Two groups of binding sites for [3H]heparin could be distinguished: one with high affinity (Kd = 0.12 microM) and another with lower affinity (Kd = 1.37 microM) and a relative large capacity of binding (1.16 X 10(7) molecules/cell) was calculated. The Kd for unlabeled heparin, as calculated from competition experiments, was 0.23 microM. Much lower affinity was calculated for unlabeled low molecular weight heparin fragments CY 222 (Kd = 4.3 microM) from competition experiments with [125I]CY 222. The binding reversibility was only partial for unfractionated heparin. Even by chasing with unlabeled compound, a fraction of 25-30% was not dissociable from endothelial cells. This fraction was much lower if incubation was carried out at 4 degrees C. The addition of basic proteins (histones) to the incubation medium greatly enhanced the undissociable binding at 37 degrees C, but not at 4 degrees C. The undissociable fraction of heparin was not available to degradation by purified microbial heparinase. These results suggest that a fraction of bound heparin is internalized by the vascular endothelium.
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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/Heparin,
http://linkedlifedata.com/resource/pubmed/chemical/Heparin Lyase,
http://linkedlifedata.com/resource/pubmed/chemical/Histones,
http://linkedlifedata.com/resource/pubmed/chemical/Polysaccharide-Lyases,
http://linkedlifedata.com/resource/pubmed/chemical/Protamines
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pubmed:status |
MEDLINE
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pubmed:month |
May
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pubmed:issn |
0006-3002
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pubmed:author | |
pubmed:issnType |
Print
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pubmed:day |
30
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pubmed:volume |
845
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
196-203
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pubmed:dateRevised |
2006-11-15
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pubmed:meshHeading |
pubmed-meshheading:3995089-Binding, Competitive,
pubmed-meshheading:3995089-Binding Sites,
pubmed-meshheading:3995089-Cells, Cultured,
pubmed-meshheading:3995089-Endocytosis,
pubmed-meshheading:3995089-Endothelium,
pubmed-meshheading:3995089-Heparin,
pubmed-meshheading:3995089-Heparin Lyase,
pubmed-meshheading:3995089-Histones,
pubmed-meshheading:3995089-Humans,
pubmed-meshheading:3995089-Kinetics,
pubmed-meshheading:3995089-Molecular Weight,
pubmed-meshheading:3995089-Polysaccharide-Lyases,
pubmed-meshheading:3995089-Protamines,
pubmed-meshheading:3995089-Umbilical Veins
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pubmed:year |
1985
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pubmed:articleTitle |
Binding and endocytosis of heparin by human endothelial cells in culture.
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pubmed:publicationType |
Journal Article,
Comparative Study
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