Switch to
Predicate | Object |
---|---|
rdf:type | |
lifeskim:mentions | |
pubmed:issue |
2
|
pubmed:dateCreated |
1977-7-23
|
pubmed:abstractText |
The binding of Ca2+ to a salivary phosphoprotein, protein C, was studied by equilibrium dialysis. In 5mM-Tris/HCl buffer, pH 7.5, protein C bound 190 nmol of Ca2+/mg of protein. The apparent dissociation constant, K, was determined to be 1.9 x 10(-4)M and the binding of Ca2+ to the protein was non-co-operative. The binding of Ca2+ to protein C apparently depends on groups which ionize above pH 5.0. Ca2+ binding decreased with increased concentration of the dialysis buffer and on addition of SrCL2, MgCl2 and MnCl2 to the dialysis buffer. Digestion of protein C with trypsin or collagenase or heating of the protein to 60 degrees or 100 degrees C had little or no effect on the Ca2+ binding. Digestion of protein C with alkaline phosphatase caused a decrease in the amount of protein-bound Ca2+. This was also found for another salivary phosphoprotein, protein A. In the absence of Ca2+ the S020,w for protein C was 1.29 S and in the presence of Ca2+ it was 1.46S. Ca2+ may cause a conformational change in the protein or an aggregation of the protein molecules. No conformational changes of protein C in the presence of Ca2+ could be detected by circular dichroism or nuclear magnetic resonance.
|
pubmed:commentsCorrections |
http://linkedlifedata.com/resource/pubmed/commentcorrection/17396-1156372,
http://linkedlifedata.com/resource/pubmed/commentcorrection/17396-13641241,
http://linkedlifedata.com/resource/pubmed/commentcorrection/17396-13826559,
http://linkedlifedata.com/resource/pubmed/commentcorrection/17396-16744959,
http://linkedlifedata.com/resource/pubmed/commentcorrection/17396-180980,
http://linkedlifedata.com/resource/pubmed/commentcorrection/17396-4518756,
http://linkedlifedata.com/resource/pubmed/commentcorrection/17396-869925
|
pubmed:language |
eng
|
pubmed:journal | |
pubmed:citationSubset |
IM
|
pubmed:chemical | |
pubmed:status |
MEDLINE
|
pubmed:month |
May
|
pubmed:issn |
0264-6021
|
pubmed:author | |
pubmed:issnType |
Print
|
pubmed:day |
1
|
pubmed:volume |
163
|
pubmed:owner |
NLM
|
pubmed:authorsComplete |
Y
|
pubmed:pagination |
241-5
|
pubmed:dateRevised |
2009-11-18
|
pubmed:meshHeading |
pubmed-meshheading:17396-Calcium,
pubmed-meshheading:17396-Dialysis,
pubmed-meshheading:17396-Hydrogen-Ion Concentration,
pubmed-meshheading:17396-Osmolar Concentration,
pubmed-meshheading:17396-Phosphoproteins,
pubmed-meshheading:17396-Protein Binding,
pubmed-meshheading:17396-Protein Conformation,
pubmed-meshheading:17396-Saliva
|
pubmed:year |
1977
|
pubmed:articleTitle |
The binding of calcium to a salivary phosphoprotein, protein C, and comparison with calcium binding to protein A, a related salivary phosphoprotein.
|
pubmed:publicationType |
Journal Article,
Comparative Study
|