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Predicate | Object |
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rdf:type | |
lifeskim:mentions | |
pubmed:issue |
2
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pubmed:dateCreated |
1996-11-25
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pubmed:abstractText |
The unfolding of bovine brain myo-inositol monophosphatase by guanidine. HCl (Gdn. HCl) has been investigated. The recovery of circular dichroism, emission spectra, and catalytic activity after dilution of Gdn.HCl-treated samples indicate that the overall process is reversible. The steepness of the spectroscopic changes between 3 M and 5 M Gdn.HCl, and the lack of any discernible plateau suggest that unfolding of the protein is a cooperative process. The sensitized luminescence of bound Tb(III) was used as a probe of conformational changes of the metal-binding loop. Denaturation of the enzyme by Gdn.HCl does not abolish sensitized luminescence. A 50% decrease in sensitized luminescence was observed in 5 M Gdn.HCl. Under this set of experimental conditions, the protein binds terbium with an association constant of 1 x 10(6)M-1. It is suggested that a residual structure of denatured myo-inositol monophosphatase is responsible for the binding of terbium ions. The kinetics of unfolding and refolding as a function of Gdn.HCl concentration were monitored by protein fluorescence in a stopped-flow instrument. The monophosphatase unfolded in a single kinetic phase with rate constants in the range 80-65 s-1 at 25 degrees C. The refolding kinetics fit monoexponential functions with rate constants in the range 120-65 s-1 depending on the Gdn.HCl concentration. Substantial refolding of the protein occurs within the dead time of mixing.
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pubmed:language |
eng
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pubmed:journal | |
pubmed:citationSubset |
IM
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pubmed:chemical |
http://linkedlifedata.com/resource/pubmed/chemical/Guanidine,
http://linkedlifedata.com/resource/pubmed/chemical/Guanidines,
http://linkedlifedata.com/resource/pubmed/chemical/Phosphoric Monoester Hydrolases,
http://linkedlifedata.com/resource/pubmed/chemical/Terbium,
http://linkedlifedata.com/resource/pubmed/chemical/myo-inositol-1 (or...
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pubmed:status |
MEDLINE
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pubmed:month |
Sep
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pubmed:issn |
0014-2956
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pubmed:author | |
pubmed:issnType |
Print
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pubmed:day |
1
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pubmed:volume |
240
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
435-42
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pubmed:dateRevised |
2007-7-23
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pubmed:meshHeading |
pubmed-meshheading:8841409-Animals,
pubmed-meshheading:8841409-Binding Sites,
pubmed-meshheading:8841409-Brain,
pubmed-meshheading:8841409-Cattle,
pubmed-meshheading:8841409-Circular Dichroism,
pubmed-meshheading:8841409-Enzyme Stability,
pubmed-meshheading:8841409-Fluorescence,
pubmed-meshheading:8841409-Guanidine,
pubmed-meshheading:8841409-Guanidines,
pubmed-meshheading:8841409-Kinetics,
pubmed-meshheading:8841409-Luminescent Measurements,
pubmed-meshheading:8841409-Phosphoric Monoester Hydrolases,
pubmed-meshheading:8841409-Protein Conformation,
pubmed-meshheading:8841409-Protein Denaturation,
pubmed-meshheading:8841409-Protein Folding,
pubmed-meshheading:8841409-Spectrometry, Fluorescence,
pubmed-meshheading:8841409-Spectrum Analysis,
pubmed-meshheading:8841409-Terbium
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pubmed:year |
1996
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pubmed:articleTitle |
Reversible denaturation of myo-inositol monophosphatase. The stability of the metal-binding loop.
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pubmed:affiliation |
Unidad de RMN, Universidad Complutense de Madrid, Spain.
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pubmed:publicationType |
Journal Article,
Research Support, Non-U.S. Gov't
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