Linked Life Data

8204608

Source:http://linkedlifedata.com/resource/pubmed/id/8204608

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
21
pubmed:dateCreated
1994-7-8
pubmed:abstractText
The S100 proteins CAPL and CACY are expressed in a tissue- and cell-specific manner and have been reported to be associated with the metastatic phenotype of tumor cells. In order to study the biochemical, cation-binding, and conformational properties, we produced and purified large amounts of the recombinant human proteins in Escherichia coli. Several characteristics of native proteins are shown to correspond to those of the bacterially expressed proteins. Both are able to form homodimers in vitro, probably the biologically active species, but not heterodimers. The Ca(2+)-binding parameters were studied by flow offlysis at physiological ionic strength. Both isotherms show a maximum of two Ca2+ per protein and are insensitive to Mg2+, indicating that the sites are of the Ca(2+)-specific type. The isotherms show slight (CAPL, nH = 1.15) or pronounced (CACY, nH = 1.33) positive cooperativity with K0.5 values of 0.32 mM (CACY) and 0.15 mM (CAPL), indicating that the sites are of the low-affinity type. Conformational changes in the Tyr microenvironment of CACY indicate that Ca2+ binding induces a shift of Tyr to a less polar environment. Mg2+ does not affect the fluorescence properties nor does it induce a difference spectrum, thus suggesting that at physiological ionic conditions it does not interact with the protein. The Ca(2+)-induced difference spectra of CAPL are about 3 times smaller than those of CACY, suggesting that the additional Tyr84 in CACY is much more sensitive to Ca2+ than the two Tyr residues conserved in both proteins.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0006-2960
pubmed:author
pubmed:issnType
Print
pubmed:day
31
pubmed:volume
33
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
6732-8
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1994
pubmed:articleTitle
Purification and characterization of the recombinant human calcium-binding S100 proteins CAPL and CACY.
pubmed:affiliation
Department of Pediatrics, University of Zürich, Switzerland.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't