Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
12
pubmed:dateCreated
1996-6-19
pubmed:abstractText
Calbindin D28k is an intracellular Ca2+-binding protein noted for its abundance and specific distribution in mammalian brain and sensory neurons. This protein contains six putative Ca2+-binding sites, referred to as EF-hands. Due to the presence of the large number of putative sites, previous studies have been unsuccessful in definitively establishing the stoichiometry of Ca2+ binding. We describe a synthetic approach to identify the number of Ca2+-binding sites in which 6 33-residue peptides, designated EF1-EF6, corresponding to the 6 EF-hand sequences of calbindin D28k, were made. The response of each peptide to Ca2+ addition was assessed by 1H NMR spectroscopy, circular dichroism (CD) spectroscopy, and agarose gel electrophoresis. The Ca2+ binding by CD experiments was performed at two peptide concentrations, 20 and 200 microM, and the NMR studies at peptide concentrations ranging from 20 to 100 microM. The CD and 1H NMR data show that five of the six peptides bind Ca2+ as isolated peptides, namely, EF1, EF3, EF4, EF5, and EF6. The EF6 peptide appears to bind Ca2+ with lower affinity than the other four functional sites. In contrast, EF2 does not appear to bind Ca2+ under any of the spectroscopic conditions tested. The data suggest that at least five of the six putative sites in the native protein bind Ca2+, although their relative affinities cannot be deduced from studies of the isolated peptides.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0006-2960
pubmed:author
pubmed:issnType
Print
pubmed:day
26
pubmed:volume
35
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
3662-9
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1996
pubmed:articleTitle
Ca2+-binding stoichiometry of calbindin D28k as assessed by spectroscopic analyses of synthetic peptide fragments.
pubmed:affiliation
Department of Chemistry, Rutgers University, Camden, New Jersey 08102, USA.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't