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Predicate | Object |
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rdf:type | |
lifeskim:mentions | |
pubmed:issue |
2
|
pubmed:dateCreated |
1989-12-18
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pubmed:abstractText |
In this study, binding and degradation of tissue-type plasminogen activator (t-PA) by the human hepatoma cell line Hep G2 was investigated. Binding at 4 degrees C was time-dependent and reached a maximum after ca. 2 hours. Scatchard analysis of saturation experiments showed about 170,000 high affinity binding sites for t-PA per cell with an apparent Kd of 90 nM. These binding sites were calcium-dependent. Part of the binding to the hepatoma cells was non-saturable, owing to a large amount of low affinity binding sites which are at least partially located on the extracellular matrix of the cells. Competition with mannose- and galactose-terminated glycoproteins had no effect on total binding of 125I-t-PA. Degradation products of 125I-t-PA were found in the supernatant after a short lag phase and then increased linearly for at least 5 hours at 37 degrees C. Degradation could be inhibited by chloroquine, NH4Cl and NaN3. We conclude that the human hepatoma cell line Hep G2 has a specific binding mechanism for t-PA which is not mediated by known carbohydrate receptor systems. Binding is followed by cellular uptake and degradation in the lysosomes.
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pubmed:language |
eng
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pubmed:journal | |
pubmed:citationSubset |
IM
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pubmed:chemical | |
pubmed:status |
MEDLINE
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pubmed:month |
Sep
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pubmed:issn |
0340-6245
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pubmed:author | |
pubmed:issnType |
Print
|
pubmed:day |
29
|
pubmed:volume |
62
|
pubmed:owner |
NLM
|
pubmed:authorsComplete |
Y
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pubmed:pagination |
667-72
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pubmed:dateRevised |
2006-11-15
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pubmed:meshHeading |
pubmed-meshheading:2510347-Binding, Competitive,
pubmed-meshheading:2510347-Calcium,
pubmed-meshheading:2510347-Humans,
pubmed-meshheading:2510347-Liver,
pubmed-meshheading:2510347-Protein Binding,
pubmed-meshheading:2510347-Tissue Plasminogen Activator,
pubmed-meshheading:2510347-Tumor Cells, Cultured
|
pubmed:year |
1989
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pubmed:articleTitle |
Binding and degradation of tissue-type plasminogen activator by the human hepatoma cell line Hep G2.
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pubmed:affiliation |
Gaubius Institute TNO, Leiden, The Netherlands.
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pubmed:publicationType |
Journal Article,
Research Support, Non-U.S. Gov't
|