Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1996-11-25
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.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
0014-2956
pubmed:author
pubmed:issnType
Print
pubmed:day
1
pubmed:volume
240
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
435-42
pubmed:dateRevised
2007-7-23
pubmed:meshHeading
pubmed:year
1996
pubmed:articleTitle
Reversible denaturation of myo-inositol monophosphatase. The stability of the metal-binding loop.
pubmed:affiliation
Unidad de RMN, Universidad Complutense de Madrid, Spain.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't