Linked Life Data

11097839

Source:http://linkedlifedata.com/resource/pubmed/id/11097839

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
2000-12-4
pubmed:abstractText
Mammalian dimeric dihydrodiol dehydrogenase is identical with d-xylose dehydrogenase and belongs to a protein family with prokaryotic proteins including glucose-fructose oxidoreductase. Of the conserved residues in this family, either His-79 or Tyr-180 of d-xylose/dihydrodiol dehydrogenase has been proposed to be involved in the catalytic function. Site-directed mutagenesis was used to examine the roles of the two residues of the monkey enzyme. A mutant, Y180F, was almost inactive, but, similarly to the wild-type enzyme, exhibited high affinity for NADP(H) and fluorescence energy transfer upon binding of NADPH. The H79Q mutation had kinetically largest effects on K(d) (>7-fold increase) and K(m) (>25-fold increase) for NADP(H), and eliminated the fluorescence energy transfer. Interestingly, the dehydrogenase activity of this mutant was potently inhibited with a 190-fold increase in the K(m) for NADP(+) by high ionic strength, which activated the activity of the wild-type enzyme. These results suggest a critical role of Tyr-180 in the catalytic function of this class of enzymes, in addition to functions of His-79 in the coenzyme binding and chemical steps of the reaction.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
0006-291X
pubmed:author
pubmed:copyrightInfo
Copyright 2000 Academic Press.
pubmed:issnType
Print
pubmed:day
19
pubmed:volume
278
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
333-7
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2000
pubmed:articleTitle
Roles of His-79 and Tyr-180 of D-xylose/dihydrodiol dehydrogenase in catalytic function.
pubmed:affiliation
Laboratory of Biochemistry, Gifu Pharmaceutical University, Gifu, Japan.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't