Linked Life Data

10600132

Source:http://linkedlifedata.com/resource/pubmed/id/10600132

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
50
pubmed:dateCreated
2000-1-19
pubmed:abstractText
Glutathione transferases function as detoxification enzymes and ligand-binding proteins for many hydrophobic endogenous and xenobiotic compounds. The molecular mechanism of folding of urea-denatured homodimeric human glutathione transferase A1-1 (hGSTA1-1) was investigated. The kinetics of change were investigated using far-UV CD, Trp20 fluorescence, fluorescence-detected ANS binding, acrylamide quenching of Trp20 fluorescence, and catalytic reactivation. The very early stages of refolding (millisecond time range) involve the formation of structured monomers with native-like secondary structure and exposed hydrophobic surfaces that have a high binding capacity for the amphipathic dye ANS. Dimerization of the monomeric intermediates was detected using Trp fluorescence and occurs as fast and intermediate events. The intermediate event was distinguished from the fast event because it is limited by a preceding slow trans-to-cis isomerization reaction (optically silent in this study). At high concentrations of hFKBP, dimerization is not limited by the isomerization reaction, and only the fast event was detected. The fast (tau = 200 ms) and intermediate (tau = 2.5 s) events show similar urea-, temperature-, and ionic strength-dependent properties. The dimeric intermediate has a partially functional active site ( approximately 20%). Final reorganization to form the native tertiary and quaternary structures occurs during a slow, unimolecular, urea- and ionic strength-independent event. During this slow event (tau = 250 s), structural rearrangements at the domain interface occur at/near Trp20 and result in burial of Trp20. The slow event results in the regain of the fully functional dimer. The role of the C-terminus helix 9 (residues 210-221) as a structural determinant for this final event is proposed.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
0006-2960
pubmed:author
pubmed:issnType
Print
pubmed:day
14
pubmed:volume
38
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
16686-94
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed-meshheading:10600132-Acrylamide, pubmed-meshheading:10600132-Anilino Naphthalenesulfonates, pubmed-meshheading:10600132-Binding Sites, pubmed-meshheading:10600132-Chromatography, High Pressure Liquid, pubmed-meshheading:10600132-Circular Dichroism, pubmed-meshheading:10600132-Dimerization, pubmed-meshheading:10600132-Enzyme Activation, pubmed-meshheading:10600132-Fluorescent Dyes, pubmed-meshheading:10600132-Glutathione Transferase, pubmed-meshheading:10600132-Humans, pubmed-meshheading:10600132-Isoenzymes, pubmed-meshheading:10600132-Protein Folding, pubmed-meshheading:10600132-Protein Structure, Secondary, pubmed-meshheading:10600132-Protein Structure, Tertiary, pubmed-meshheading:10600132-Spectrometry, Fluorescence, pubmed-meshheading:10600132-Stereoisomerism, pubmed-meshheading:10600132-Thermodynamics, pubmed-meshheading:10600132-Tryptophan
pubmed:year
1999
pubmed:articleTitle
Folding and assembly of dimeric human glutathione transferase A1-1.
pubmed:affiliation
Protein Structure-Function Research Program, Department of Molecular and Cell Biology, University of the Witwatersrand, Johannesburg, South Africa.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't