Linked Life Data

10656828

Source:http://linkedlifedata.com/resource/pubmed/id/10656828

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
2000-3-14
pubmed:abstractText
The changes in the free energy of the denatured state of a set of yeast iso-1-cytochrome c variants with single surface histidine residues have been measured in 3 M guanidine hydrochloride. The thermodynamics of unfolding by guanidine hydrochloride is also reported. All variants have decreased stability relative to the wild-type protein. The free energy of the denatured state was determined in 3 M guanidine hydrochloride by evaluating the strength of heme-histidine ligation through determination of the pK(a) for loss of histidine binding to the heme. The data are corrected for the presence of the N-terminal amino group which also ligates to the heme under similar solution conditions. Significant deviations from random coil behavior are observed. Relative to a variant with a single histidine at position 26, residual structure of the order of -1.0 to -2.5 kcal/mol is seen for the other variants studied. The data explain the slower folding of yeast iso-1-cytochrome c relative to the horse protein. The greater number of histidines and the greater strength of ligation are expected to slow conversion of the histidine-misligated forms to the obligatory aquo-heme intermediate during the ligand exchange phase of folding. The particularly strong association of histidine residues at positions 54 and 89 may indicate regions of the protein with strong energetic propensities to collapse against the heme during early folding events, consistent with available data in the literature on early folding events for cytochrome c.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
0022-2836
pubmed:author
pubmed:copyrightInfo
Copyright 2000 Academic Press.
pubmed:issnType
Print
pubmed:day
11
pubmed:volume
296
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
217-28
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed-meshheading:10656828-Binding, Competitive, pubmed-meshheading:10656828-Biopolymers, pubmed-meshheading:10656828-Circular Dichroism, pubmed-meshheading:10656828-Cytochrome c Group, pubmed-meshheading:10656828-Cytochromes c, pubmed-meshheading:10656828-Enzyme Stability, pubmed-meshheading:10656828-Genetic Variation, pubmed-meshheading:10656828-Guanidine, pubmed-meshheading:10656828-Heme, pubmed-meshheading:10656828-Histidine, pubmed-meshheading:10656828-Hydrogen-Ion Concentration, pubmed-meshheading:10656828-Kinetics, pubmed-meshheading:10656828-Ligands, pubmed-meshheading:10656828-Models, Chemical, pubmed-meshheading:10656828-Protein Conformation, pubmed-meshheading:10656828-Protein Denaturation, pubmed-meshheading:10656828-Protein Folding, pubmed-meshheading:10656828-Saccharomyces cerevisiae, pubmed-meshheading:10656828-Saccharomyces cerevisiae Proteins, pubmed-meshheading:10656828-Thermodynamics, pubmed-meshheading:10656828-Titrimetry
pubmed:year
2000
pubmed:articleTitle
Measuring denatured state energetics: deviations from random coil behavior and implications for the folding of iso-1-cytochrome c.
pubmed:affiliation
Department of Chemistry and Biochemistry, University of Denver, 2190 East Iliff Avenue, Denver, CO 80208-2436, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.