Linked Life Data

6469946

Source:http://linkedlifedata.com/resource/pubmed/id/6469946

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6
pubmed:dateCreated
1984-10-12
pubmed:abstractText
Quantitative analyses were carried out on Tb3+ binding to porcine intestinal calcium-binding protein (CaBP). Tb3+ (emission at 547 nm) and intrinsic tyrosine (emission at 303 nm) fluorescences upon excitation at 260 nm increase almost in parallel with increasing Tb3+ concentration up to a molar ratio of 2 against the protein in the CaBP solution. The pH dependence profile of Tb3+ fluorescence of the Tb3+-CaBP complex suggests that some free carboxylate groups are involved in the binding, as also suggested for Ca2+ binding. The results of fluorometric titration of Tb3+ and intrinsic tyrosine fluorescences of the CaBP complex with Tb3+ or Ca2+ led us to conclude that Tb3+ and Ca2+ have two common binding sites for each CaBP molecule. An equilibrium dialysis experiment showed that the dissociation constants of the two Tb3+-binding sites are 0.29 and 3.51 microM. Tb3+ strongly inhibits 45Ca binding to one of the two Ca2+-binding sites in the CaBP. All of these and previous results indicate that each Tb3+ ion can bind to either of two high-affinity Ca2+-binding sites in porcine intestinal CaBP with an affinity different from that for Ca2+ ion. We discuss the localization of the Ca2+- and Tb3+-binding sites in the CaBP.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0021-924X
pubmed:author
pubmed:issnType
Print
pubmed:volume
95
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1767-74
pubmed:dateRevised
2007-12-19
pubmed:meshHeading
pubmed:year
1984
pubmed:articleTitle
Stoichiometry and location of terbium and calcium bindings to porcine intestinal calcium-binding protein.
pubmed:publicationType
Journal Article