Linked Life Data

8939892

Source:http://linkedlifedata.com/resource/pubmed/id/8939892

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
47
pubmed:dateCreated
1997-1-13
pubmed:abstractText
Autophosphorylation of Ca2+/calmodulin-dependent protein kinase II (CaM-kinase) induces a more than 1000-fold increase in calmodulin (CaM)-binding affinity by dramatically decreasing the off-rate for CaM. In this report, we investigate the molecular mechanism for this phenomenon by comparing the rate of dissociation of a novel fluorescently labeled CaM from two synthetic peptides and from the phosphorylated and nonphosphorylated forms of a recombinant preparation of CaM-kinase. Dissociation of a complex of CaM and CKII(296-312), a peptide representing close to the minimum CaM-binding domain of the alpha subunit of CaM-kinase, exhibited a fast off-rate of 5.0 s-1. This was similar to the off-rate of 1.1 s-1 for the dissociation of CaM from the nonphosphorylated form of CaM-kinase. In contrast, dissociation of CaM from either autophosphorylated CaM-kinase or peptide CKII(290-314) was extremely slow with apparent off-rates of about 3-9 x 10(-5) s-1. Along with information from the crystal structure of Ca2+/CaM bound to CKII(290-314) (Meador, W. E., Means, A. R., and Quiocho, F. A. (1993) Science 262, 1718-1721), our results suggest a model in which CaM-dependent autophosphorylation of CaM-kinase induces a conformational change in the region of the CaM-binding domain which allows the formation of additional stabilizing interactions with CaM. We predict that this involves amino acids 293-298 in CaM-kinase. The possible consequences of these observations on the reversibility of CaM trapping in native CaM-kinase are discussed.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
22
pubmed:volume
271
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
29619-23
pubmed:dateRevised
2007-11-15
pubmed:meshHeading
pubmed:year
1996
pubmed:articleTitle
A peptide model for calmodulin trapping by calcium/calmodulin-dependent protein kinase II.
pubmed:affiliation
Department of Biochemistry and Molecular Biology, University of Texas Medical School, Houston, Texas 77225, USA. nwaxham@nba19.med.uth.tmc.edu
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't