Linked Life Data

8660680

Source:http://linkedlifedata.com/resource/pubmed/id/8660680

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1996-8-15
pubmed:abstractText
The reaction mechanism of a 1,4-benzoquinone reductase from the wood-rotting basidiomycete Phanerochaete chrysosporium was investigated. The native, oxidized, FMN-containing enzyme was reduced quantitatively by NADH and the resulting reduced enzyme was reoxidized in the presence of one equivalent of 2,6-di-methoxy-1,4-benzoquinone (DMBQ). The stoichiometry of NADH oxidation versus DMBQ reduction is 1:1. The enzyme catalyzes the reduction of quinones to hydroquinones by a ping-pong steady-state mechanism. However, inhibition is observed at low NADH concentrations. Quinone products derived from the autooxidation of the unstable compounds 1,2,4-trihydroxybenzene and 5-chloro-2,3,4-trihydroxybenzene also appear to be substrates for the quinone reductase. The enzyme reduces the one-electron acceptors ferricyanide and ferricytochrome c (Cc3+) with rates of 58.4 and 0.08%, respectively, compared to DMBQ. The stoichiometry of NADH oxidation versus ferricyanide reduction is 1:2. In the presence of quinones the rates of Cc3+ and ferricyanide reduction are increased, owing to the nonenzymatic reduction of these acceptors by enzyme-generated hydroquinone products. Dicumarol and Cibacron blue are competitive inhibitors with respect to NADH, with Ki values of 2.1 and 0.30 microM, respectively. Reconstitution of the apoprotein with FMN yields a fully active enzyme at an FMN-to-protein ratio of 2:1, suggesting that the flavin content of the enzyme is two molecules of FMN per dimer.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
http://linkedlifedata.com/resource/pubmed/chemical/2,6-dimethoxy-1,4-benzoquinone, http://linkedlifedata.com/resource/pubmed/chemical/Benzoquinones, http://linkedlifedata.com/resource/pubmed/chemical/Cibacron Blue F 3GA, http://linkedlifedata.com/resource/pubmed/chemical/Cytochrome c Group, http://linkedlifedata.com/resource/pubmed/chemical/Dicumarol, http://linkedlifedata.com/resource/pubmed/chemical/Enzyme Inhibitors, http://linkedlifedata.com/resource/pubmed/chemical/Ferricyanides, http://linkedlifedata.com/resource/pubmed/chemical/Flavin Mononucleotide, http://linkedlifedata.com/resource/pubmed/chemical/Hydroquinones, http://linkedlifedata.com/resource/pubmed/chemical/NAD, http://linkedlifedata.com/resource/pubmed/chemical/Quinone Reductases, http://linkedlifedata.com/resource/pubmed/chemical/Quinones, http://linkedlifedata.com/resource/pubmed/chemical/Triazines, http://linkedlifedata.com/resource/pubmed/chemical/hexacyanoferrate III
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
0003-9861
pubmed:author
pubmed:issnType
Print
pubmed:day
1
pubmed:volume
331
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
31-40
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1996
pubmed:articleTitle
1,4-Benzoquinone reductase from basidiomycete Phanerochaete chrysosporium: spectral and kinetic analysis.
pubmed:affiliation
Department of Chemistry,Biochemistry, and Molecular Biology, Oregon Graduate Institute of Science and Technology, Portland, Oregon 97291-1000, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, Non-P.H.S.