Source:http://linkedlifedata.com/resource/pubmed/id/12220083
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| Predicate | Object |
|---|---|
| rdf:type | |
| lifeskim:mentions | |
| pubmed:issue |
6
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| pubmed:dateCreated |
2002-9-10
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| pubmed:abstractText |
Osteopontin (OPN) is an extracellular matrix protein found in bones and teeth, where it accumulates at matrix-matrix interfaces. We postulate that OPN interacts homotypically and heterotypically in the adhesion of apposing matrices. Using suspensions of OPN-coupled aldehyde/sulfate latex spheres, we measured the strength of homotypic OPN-OPN binding in vitro. Doublets formed through shear-induced collisions in a cone and plate rheoscope were subjected to shear stresses >0.6 Nm(-2) and the fraction broken up determined over 60 s. Rapid initial breakup of 35% of doublets was followed by very slow breakup of the remaining 65%. Monte Carlo simulation of the breakup kinetics pointed to the existence of low and high bond strength populations of doublets. Dynamic light scattering spectroscopy of soluble OPN showed that 27% by mass existed as dimers. We postulate that OPN dimers binding to monomers account for the low strength bonds since a strong bond has already formed between the molecules of the dimer. In contrast, OPN-OPN monomer bonds had higher tensile strength than bonds between the high-affinity interaction of IgG and protein G, previously studied. Antibody blocking studies showed that the self-binding region of OPN resides in the C-terminus. These data suggest that homotypic OPN-OPN bonds have physiologically significant strength, supporting the hypothesis that OPN-OPN binding and self-assembly participate in adhesion within mineralized tissues.
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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 |
Jun
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| pubmed:issn |
0090-6964
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| pubmed:author | |
| pubmed:issnType |
Print
|
| pubmed:volume |
30
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| pubmed:owner |
NLM
|
| pubmed:authorsComplete |
Y
|
| pubmed:pagination |
840-50
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| pubmed:dateRevised |
2006-11-15
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| pubmed:meshHeading |
pubmed-meshheading:12220083-Animals,
pubmed-meshheading:12220083-Cattle,
pubmed-meshheading:12220083-Cell Adhesion,
pubmed-meshheading:12220083-Cell Aggregation,
pubmed-meshheading:12220083-Computer Simulation,
pubmed-meshheading:12220083-Flow Cytometry,
pubmed-meshheading:12220083-Macromolecular Substances,
pubmed-meshheading:12220083-Mice,
pubmed-meshheading:12220083-Microspheres,
pubmed-meshheading:12220083-Milk,
pubmed-meshheading:12220083-Models, Chemical,
pubmed-meshheading:12220083-Molecular Weight,
pubmed-meshheading:12220083-Monte Carlo Method,
pubmed-meshheading:12220083-Osteopontin,
pubmed-meshheading:12220083-Protein Binding,
pubmed-meshheading:12220083-Rheology,
pubmed-meshheading:12220083-Sialoglycoproteins,
pubmed-meshheading:12220083-Stress, Mechanical
|
| pubmed:year |
2002
|
| pubmed:articleTitle |
Homotypic interactions of soluble and immobilized osteopontin.
|
| pubmed:affiliation |
Department of Medicine, Montreal General Hospital, Montreal, QC, Canada.
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| pubmed:publicationType |
Journal Article,
Comparative Study,
Research Support, Non-U.S. Gov't
|