Source:http://linkedlifedata.com/resource/pubmed/id/10913121
Switch to
| Predicate | Object |
|---|---|
| rdf:type | |
| lifeskim:mentions | |
| pubmed:issue |
40
|
| pubmed:dateCreated |
2000-10-23
|
| pubmed:abstractText |
Pregnancy-associated plasma protein-A (PAPP-A), originally known from human pregnancy serum, has recently been demonstrated to be a metzincin superfamily metalloproteinase involved in normal and pathological insulin-like growth factor (IGF) physiology. PAPP-A specifically cleaves IGF-binding protein (IGFBP)-4, one of six antagonists of IGF action, which results in release of IGF bound to IGFBP-4. IGFBP-4 is the only known PAPP-A substrate. Its cleavage by PAPP-A uniquely depends on the presence of IGF. We here report mammalian expression and purification of recombinant 1547-residue PAPP-A (rPAPP-A). The recombinant protein is secreted as a homodimer of about 400 kDa composed of two 200-kDa disulfide-bound subunits. Antigenically and functionally, rPAPP-A behaves like the native protein. In human pregnancy, PAPP-A is known to circulate as a 500-kDa disulfide-bound 2:2 complex with the proform of eosinophil major basic protein (proMBP), PAPP-A/proMBP. A comparison between rPAPP-A and pregnancy serum PAPP-A/proMBP complex surprisingly reveals a difference greater than 100-fold in proteolytic activity, showing that proMBP functions as a proteinase inhibitor in vivo. We find that polyclonal antibodies against PAPP-A abrogate all detectable IGFBP-4 proteolytic activity in pregnancy serum, pointing at PAPP-A as the dominating, if not the only, IGFBP-4 proteinase present in the circulation. We further show that pregnancy serum and plasma contain traces (<1%) of uncomplexed PAPP-A with a much higher specific activity than the PAPP-A/proMBP complex. The measurable activity of the PAPP-A/proMBP complex probably results from the presence of a minor subpopulation of partly inhibited PAPP-A that exists in a 2:1 complex with proMBP. Inhibition of PAPP-A by proMBP represents a novel inhibitory mechanism with the enzyme irreversibly bound to its inhibitor by disulfide bonds.
|
| pubmed:language |
eng
|
| pubmed:journal | |
| pubmed:citationSubset |
IM
|
| pubmed:chemical |
http://linkedlifedata.com/resource/pubmed/chemical/Blood Proteins,
http://linkedlifedata.com/resource/pubmed/chemical/DNA, Complementary,
http://linkedlifedata.com/resource/pubmed/chemical/Disulfides,
http://linkedlifedata.com/resource/pubmed/chemical/Enzyme Precursors,
http://linkedlifedata.com/resource/pubmed/chemical/Eosinophil Granule Proteins,
http://linkedlifedata.com/resource/pubmed/chemical/Insulin-Like Growth Factor Binding...,
http://linkedlifedata.com/resource/pubmed/chemical/Metalloendopeptidases,
http://linkedlifedata.com/resource/pubmed/chemical/Pregnancy-Associated Plasma...,
http://linkedlifedata.com/resource/pubmed/chemical/Recombinant Proteins,
http://linkedlifedata.com/resource/pubmed/chemical/Ribonucleases,
http://linkedlifedata.com/resource/pubmed/chemical/Somatomedins
|
| pubmed:status |
MEDLINE
|
| pubmed:month |
Oct
|
| pubmed:issn |
0021-9258
|
| pubmed:author | |
| pubmed:issnType |
Print
|
| pubmed:day |
6
|
| pubmed:volume |
275
|
| pubmed:owner |
NLM
|
| pubmed:authorsComplete |
Y
|
| pubmed:pagination |
31128-33
|
| pubmed:dateRevised |
2006-11-15
|
| pubmed:meshHeading |
pubmed-meshheading:10913121-Blood Proteins,
pubmed-meshheading:10913121-Blotting, Western,
pubmed-meshheading:10913121-Cell Line,
pubmed-meshheading:10913121-Chromatography, Ion Exchange,
pubmed-meshheading:10913121-DNA, Complementary,
pubmed-meshheading:10913121-Disulfides,
pubmed-meshheading:10913121-Electrophoresis, Polyacrylamide Gel,
pubmed-meshheading:10913121-Enzyme Precursors,
pubmed-meshheading:10913121-Enzyme-Linked Immunosorbent Assay,
pubmed-meshheading:10913121-Eosinophil Granule Proteins,
pubmed-meshheading:10913121-Eosinophils,
pubmed-meshheading:10913121-Female,
pubmed-meshheading:10913121-Humans,
pubmed-meshheading:10913121-Insulin-Like Growth Factor Binding Protein 4,
pubmed-meshheading:10913121-Metalloendopeptidases,
pubmed-meshheading:10913121-Plasmids,
pubmed-meshheading:10913121-Pregnancy,
pubmed-meshheading:10913121-Pregnancy-Associated Plasma Protein-A,
pubmed-meshheading:10913121-Recombinant Proteins,
pubmed-meshheading:10913121-Ribonucleases,
pubmed-meshheading:10913121-Somatomedins,
pubmed-meshheading:10913121-Transfection
|
| pubmed:year |
2000
|
| pubmed:articleTitle |
Expression of recombinant human pregnancy-associated plasma protein-A and identification of the proform of eosinophil major basic protein as its physiological inhibitor.
|
| pubmed:affiliation |
Department of Molecular and Structural Biology, Science Park, University of Aarhus, Gustav Wieds Vej 10C, DK-8000 Aarhus C, Denmark.
|
| pubmed:publicationType |
Journal Article,
Research Support, Non-U.S. Gov't
|