Linked Life Data

6693423

Source:http://linkedlifedata.com/resource/pubmed/id/6693423

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1984-3-16
pubmed:abstractText
The flavin prosthetic group (FAD) of the aromatic hydroxylases melilotate hydroxylase (EC 1.14.13.4) and phenol hydroxylase (EC 1.14.13.7) was replaced by 1-deaza-FAD (carbon substituted for nitrogen at position 1). Neither modified enzyme could hydroxylate its substrate, both catalyzed the oxidation of NAD(P)H to NAD(P)+ and H2O2. The rate of the reduction of the enzymes by NAD(P)H was increased by the binding of substrate. Both enzymes formed a detectable flavin C(4a) hydroperoxide intermediate upon reaction of the reduced enzyme-substrate complex with oxygen. Reduced 1-deaza-FAD phenol hydroxylase also showed a detectable C(4a) hydroperoxide intermediate when reacted with oxygen in the absence of substrate. The C(4a) hydroperoxide of 1-deaza-FAD phenol hydroxylase, in the absence of phenol, decayed to an intermediate which showed a perturbed oxidized enzyme spectrum, Eox. This intermediate in turn decayed to give the original oxidized enzyme. In the presence of phenol, a second oxidized species with a perturbed spectrum, intermediate X, was apparent after formation of the flavin C(4a) hydroperoxide and before Eox formation. Steady state kinetic analysis of 1-deaza-FAD phenol hydroxylase demonstrated that the Eox to Eox conversion was not in the catalytic cycle. During turnover Eox was reduced by NADPH.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
10
pubmed:volume
259
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1532-8
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1984
pubmed:articleTitle
Reactions of 1-deaza-FAD-substituted phenol hydroxylase and melilotate hydroxylase.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.