Linked Life Data

10764757

Source:http://linkedlifedata.com/resource/pubmed/id/10764757

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
25
pubmed:dateCreated
2000-8-16
pubmed:abstractText
The heat shock protein Hsp33 is a very potent molecular chaperone with a distinctive mode of functional regulation; its activity is redox-regulated. In its reduced form all six cysteinyl residues of Hsp33 are present as thiols, and Hsp33 displays no folding helper activity. Exposure of Hsp33 to oxidizing conditions like H(2)O(2), however, rapidly converts Hsp33 into an efficient molecular chaperone. Activated Hsp33 binds tightly to refolding intermediates of chemically denatured luciferase and suppresses efficiently their aggregation in vitro. Matrix-assisted laser desorption/ionization-mass spectrometry peptide mapping in combination with in vitro and on target protein chemical modification showed that this activation process of Hsp33 is accompanied by the formation of two intramolecular disulfide bonds within Hsp33: Cys(232)-S-S-Cys(234) and Cys(265)-S-S-Cys(268). Cys(141), although not involved in disulfide bond formation, was found highly reactive toward chemical modifications. In contrast, Cys(239) is readily accessible under reducing conditions but becomes poorly accessible though still reduced when Hsp33 is in its active state. This indicates a significant conformational change during the activation process of Hsp33. Mass spectrometry, thus, unraveled a novel molecular mechanism by which alteration of the disulfide bond structure, as a result of changes in the cellular redox potential, results in the activation of a molecular chaperone.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
23
pubmed:volume
275
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
18759-66
pubmed:dateRevised
2009-7-17
pubmed:meshHeading
pubmed:year
2000
pubmed:articleTitle
Mass spectrometry unravels disulfide bond formation as the mechanism that activates a molecular chaperone.
pubmed:affiliation
Faculty of Chemistry, University of Konstanz, Box M732, D-78457 Konstanz, Germany.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't