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rdf:type |
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lifeskim:mentions |
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pubmed:issue |
48
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pubmed:dateCreated |
1994-1-6
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pubmed:abstractText |
Smooth muscle calponin bound to the biologically active fluorescent calmodulin [2-(4'-maleimidoanilino)naphthalene-6-sulfonic acid-calmodulin] (MIANS.CaM) with a Kd of 80 nM and produced a 3.4-fold fluorescence enhancement. PKC-phosphorylated calponin (1.3 mol of Pi/mol) bound to CaM with approximately 15-fold lower affinity. Calponin inhibited CaM (10 nM) activation of the Ca(2+)-/CaM-activated cyclic nucleotide phosphodiesterase (PDE) with an IC50 of 138 nM. The calponin-CaM interaction was Ca(2+)-dependent: half-maximal binding of calponin to MIANS.CaM occurred at pCa 6.6 with a Hill coefficient of 2.4. Stopped-flow fluorescence kinetic analysis demonstrated that EGTA chelation of Ca2+ from CaM disrupted the MIANS.CaM-calponin complex at a rate of 1 s-1. Calponin bound MIANS.CaM at a rate of (6.0 +/- 1.8) x 10(6) M-1s-1, and melittin and unlabeled brain CaM both disrupted the MIANS.CaM-calponin complex at a rate of 0.3 +/- 0.1 s-1. These studies suggest that calponin binds CaM with 80-fold lower affinity than myosin light-chain kinase and that calponin associates with CaM much slower than it associates with caldesmon or myosin light-chain kinase. The physiological relevance of the CaM-calponin interaction was evaluated by analysis of the effects of Ca(2+)-CaM on (i) the interaction of calponin with actin and (ii) calponin-mediated inhibition of actin-activated myosin MgATPase activity. Ca(2+)-CaM half-maximally inhibited calponin (2 microM) binding to smooth and skeletal muscle actins (9 microM) at 5.4 and 11 microM CaM, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)
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pubmed:grant |
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pubmed:language |
eng
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pubmed:journal |
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pubmed:citationSubset |
IM
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pubmed:chemical |
http://linkedlifedata.com/resource/pubmed/chemical/3',5'-Cyclic-GMP Phosphodiesterases,
http://linkedlifedata.com/resource/pubmed/chemical/Actins,
http://linkedlifedata.com/resource/pubmed/chemical/Actomyosin,
http://linkedlifedata.com/resource/pubmed/chemical/Calcium,
http://linkedlifedata.com/resource/pubmed/chemical/Calcium-Binding Proteins,
http://linkedlifedata.com/resource/pubmed/chemical/Calmodulin,
http://linkedlifedata.com/resource/pubmed/chemical/Calmodulin-Binding Proteins,
http://linkedlifedata.com/resource/pubmed/chemical/Egtazic Acid,
http://linkedlifedata.com/resource/pubmed/chemical/Melitten,
http://linkedlifedata.com/resource/pubmed/chemical/Microfilament Proteins,
http://linkedlifedata.com/resource/pubmed/chemical/Myosin-Light-Chain Kinase,
http://linkedlifedata.com/resource/pubmed/chemical/Myosins,
http://linkedlifedata.com/resource/pubmed/chemical/calponin
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pubmed:status |
MEDLINE
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pubmed:month |
Dec
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pubmed:issn |
0006-2960
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pubmed:author |
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pubmed:issnType |
Print
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pubmed:day |
7
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pubmed:volume |
32
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
13327-33
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pubmed:dateRevised |
2009-11-19
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pubmed:meshHeading |
pubmed-meshheading:8241189-3',5'-Cyclic-GMP Phosphodiesterases,
pubmed-meshheading:8241189-Actins,
pubmed-meshheading:8241189-Actomyosin,
pubmed-meshheading:8241189-Amino Acid Sequence,
pubmed-meshheading:8241189-Animals,
pubmed-meshheading:8241189-Calcium,
pubmed-meshheading:8241189-Calcium-Binding Proteins,
pubmed-meshheading:8241189-Calmodulin,
pubmed-meshheading:8241189-Calmodulin-Binding Proteins,
pubmed-meshheading:8241189-Cattle,
pubmed-meshheading:8241189-Chickens,
pubmed-meshheading:8241189-Egtazic Acid,
pubmed-meshheading:8241189-Kinetics,
pubmed-meshheading:8241189-Melitten,
pubmed-meshheading:8241189-Microfilament Proteins,
pubmed-meshheading:8241189-Molecular Sequence Data,
pubmed-meshheading:8241189-Muscle, Smooth,
pubmed-meshheading:8241189-Muscle Contraction,
pubmed-meshheading:8241189-Muscles,
pubmed-meshheading:8241189-Myosin-Light-Chain Kinase,
pubmed-meshheading:8241189-Myosins,
pubmed-meshheading:8241189-Rabbits
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pubmed:year |
1993
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pubmed:articleTitle |
Calponin-calmodulin interaction: properties and effects on smooth and skeletal muscle actin binding and actomyosin ATPases.
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pubmed:affiliation |
MRC Signal Transduction Group, University of Calgary, Alberta, Canada.
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pubmed:publicationType |
Journal Article,
In Vitro,
Research Support, U.S. Gov't, P.H.S.,
Research Support, Non-U.S. Gov't
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