Linked Life Data

18275157

Source:http://linkedlifedata.com/resource/pubmed/id/18275157

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
10
pubmed:dateCreated
2008-3-4
pubmed:abstractText
Tetrachlorohydroquinone (TCHQ) dehalogenase is profoundly inhibited by its aromatic substrates, TCHQ and trichlorohydroquinone (TriCHQ). Surprisingly, mutations that change Ile12 to either Ser or Ala give an enzyme that shows no substrate inhibition. We have previously shown that TriCHQ is a noncompetitive inhibitor of the thiol-disulfide exchange reaction between glutathione and ESSG, a covalent adduct between Cys13 and glutathione formed during dehalogenation of the substrate. Substrate inhibition of the thiol-disulfide exchange reaction is less severe in the I12S and I12A mutant enzymes, primarily due to weaker binding of TriCHQ to ESSG. These mutations also result in a decrease in the rate of dehalogenation. Because the rate-limiting step in the I12S and I12A enzymes is dehalogenation, rather than the thiol-disulfide exchange reaction, the relatively modest inhibition of the thiol-disulfide exchange reaction does not affect the overall rate of turnover.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0006-2960
pubmed:author
pubmed:issnType
Print
pubmed:day
11
pubmed:volume
47
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
3258-65
pubmed:meshHeading
pubmed:year
2008
pubmed:articleTitle
A trade-off between catalytic power and substrate inhibition in TCHQ dehalogenase.
pubmed:affiliation
Department of Molecular, Cellular, and Developmental Biology and Cooperative Institute for Research in Environmental Sciences, University of Colorado at Boulder, Boulder, Colorado 80309, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, Non-P.H.S.