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Predicate | Object |
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rdf:type | |
lifeskim:mentions | |
pubmed:issue |
7
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pubmed:dateCreated |
1981-7-23
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pubmed:abstractText |
The mechanism of hepatic NADPH-cytochrome P-450 reductase has been investigated by using a stopped-flow technique. The reduction of the oxidized native enzyme (FAD-FMN) by NADPH proceeds by both one-electron equivalent and two-electron eqiuvalent mechanisms. The air-stable semiquinone form (FAD-FMNH.) of the native enzyme, which is characterized by an absorption shoulder at 635 nm, is also rapidly reduced to another semiquinone form (FADH-FMNH2) by NADPH with the disappearance of the shoulder at 635 nm, but the absorbance change at 585 nm is relatively constant. The FAD moiety in the FMN-depleted enzyme is rapidly reduced by NADPH, and reduced FAD is oxidized in successive one-electron steps by O2 or potassium ferricyanide. These results indicate the possibility of intra-molecular one-electron transfer between FAD and FMN. The rate of cytochrome P-450 reduction decreases in the presence of FMN-depleted enzyme but is nearly restored to the value of the original enzyme with FMN-reconstituted enzyme. These data suggest that FAD is the low-potential flavin, which serves as an electron acceptor from NADPH. On the other hand, FMN, which is the high-potential flavin, appears to participate as an electron carrier in the process of electron transfer from NADPH to cytochrome P-450 during the mixed-function catalytic cycle.
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pubmed:language |
eng
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pubmed:journal | |
pubmed:citationSubset |
IM
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pubmed:chemical |
http://linkedlifedata.com/resource/pubmed/chemical/Flavin Mononucleotide,
http://linkedlifedata.com/resource/pubmed/chemical/Flavin-Adenine Dinucleotide,
http://linkedlifedata.com/resource/pubmed/chemical/Liposomes,
http://linkedlifedata.com/resource/pubmed/chemical/Mixed Function Oxygenases,
http://linkedlifedata.com/resource/pubmed/chemical/NADPH-Ferrihemoprotein Reductase,
http://linkedlifedata.com/resource/pubmed/chemical/Oxidoreductases,
http://linkedlifedata.com/resource/pubmed/chemical/Phospholipids
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pubmed:status |
MEDLINE
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pubmed:month |
Mar
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pubmed:issn |
0006-2960
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pubmed:author | |
pubmed:issnType |
Print
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pubmed:day |
31
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pubmed:volume |
20
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
1722-30
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pubmed:dateRevised |
2006-11-15
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pubmed:meshHeading |
pubmed-meshheading:6784758-Animals,
pubmed-meshheading:6784758-Flavin Mononucleotide,
pubmed-meshheading:6784758-Flavin-Adenine Dinucleotide,
pubmed-meshheading:6784758-Kinetics,
pubmed-meshheading:6784758-Liposomes,
pubmed-meshheading:6784758-Microsomes, Liver,
pubmed-meshheading:6784758-Mixed Function Oxygenases,
pubmed-meshheading:6784758-NADPH-Ferrihemoprotein Reductase,
pubmed-meshheading:6784758-Oxidation-Reduction,
pubmed-meshheading:6784758-Oxidoreductases,
pubmed-meshheading:6784758-Phospholipids,
pubmed-meshheading:6784758-Spectrophotometry,
pubmed-meshheading:6784758-Swine
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pubmed:year |
1981
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pubmed:articleTitle |
Studies on the microsomal mixed-function oxidase system: mechanism of action of hepatic NADPH-cytochrome P-450 reductase.
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pubmed:publicationType |
Journal Article
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