Switch to
| Predicate | Object |
|---|---|
| rdf:type | |
| lifeskim:mentions | |
| pubmed:issue |
16
|
| pubmed:dateCreated |
1991-7-1
|
| pubmed:abstractText |
Calcifiable proteolipids present in mineralizing tissues have been postulated to enhance apatite deposition by structuring membrane phosphatidylserine molecules into a conformation conducive to mineral formation. To examine whether proteolipid-like molecules are present in mineralizable matrix vesicles (MV), the vesicles were first extracted with chloroform/methanol (2:1, v/v), and then with chloroform/methanol/HCl (200:100:1, v/v) and the organic-soluble proteins subjected to sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis. Protein fractions were analyzed by Coomassie Blue staining and by immunoblot analysis of electrophoretically transferred MV protein with antisera to the 33- and 36-kDa annexins. We found that several MV proteins selectively partitioned into the lipophilic milieu under acidic conditions; however, very little protein did so at neutral pH. The principal organic-soluble MV proteins had molecular masses of 14, 33, and 36 kDa, with lesser bands at 28, 30, and 68 kDa. Immunological analyses revealed that the 33- and 36-kDa proteins were the MV annexins; the 14-kDa protein appeared to be hemoglobin, based on NH2-terminal sequencing. Our findings indicate that under acidic conditions the 33- and 36-kDa MV annexins undergo a conformational change which imparts a marked increase in the hydrophobicity of the proteins. While these observations reveal that the annexins possess proteolipid-like properties, radiolabeling and immunoprecipitation studies using [3H]myristic acid in chondrocyte cultures indicate that the MV annexins are not myristylated. Amino-terminal sequence analysis of the peptides generated by site-specific cleavage of the 33- and the 36-kDa MV annexins at tryptophan residues indicate that the 33 kDa is highly homologous to anchorin CII, a protein known to bind type II collagen, while the 36-kDa protein shares close homology with endonexin II, a tyrosine kinase substrate.
|
| pubmed:grant | |
| pubmed:language |
eng
|
| pubmed:journal | |
| pubmed:citationSubset |
IM
|
| pubmed:chemical | |
| pubmed:status |
MEDLINE
|
| pubmed:month |
Jun
|
| pubmed:issn |
0021-9258
|
| pubmed:author | |
| pubmed:issnType |
Print
|
| pubmed:day |
5
|
| pubmed:volume |
266
|
| pubmed:owner |
NLM
|
| pubmed:authorsComplete |
Y
|
| pubmed:pagination |
10678-85
|
| pubmed:dateRevised |
2007-11-14
|
| pubmed:meshHeading |
pubmed-meshheading:2037607-Amino Acid Sequence,
pubmed-meshheading:2037607-Animals,
pubmed-meshheading:2037607-Blotting, Western,
pubmed-meshheading:2037607-Calcium-Binding Proteins,
pubmed-meshheading:2037607-Cartilage,
pubmed-meshheading:2037607-Cells, Cultured,
pubmed-meshheading:2037607-Chickens,
pubmed-meshheading:2037607-Electrophoresis, Polyacrylamide Gel,
pubmed-meshheading:2037607-Extracellular Matrix Proteins,
pubmed-meshheading:2037607-Molecular Sequence Data,
pubmed-meshheading:2037607-Precipitin Tests,
pubmed-meshheading:2037607-Protein Conformation,
pubmed-meshheading:2037607-Proteolipids
|
| pubmed:year |
1991
|
| pubmed:articleTitle |
Matrix vesicle annexins exhibit proteolipid-like properties. Selective partitioning into lipophilic solvents under acidic conditions.
|
| pubmed:affiliation |
Department of Chemistry, University of South Carolina, Columbia 29208.
|
| pubmed:publicationType |
Journal Article,
Research Support, U.S. Gov't, P.H.S.
|