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Predicate | Object |
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rdf:type | |
lifeskim:mentions | |
pubmed:issue |
2
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pubmed:dateCreated |
1987-12-4
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pubmed:abstractText |
In the course of studies on the oxygenation of steroids by purified P-450 cytochromes, particularly rabbit liver microsomal cytochrome P-450 form 3b, a rapid and reliable radiometric assay has been devised for progesterone 16 alpha-hydroxylation. In view of the lack of a commercially available, suitably tritiated substrate, [1,2,6,7,16,17-3H]progesterone was treated with alkali to remove the label from potential hydroxylation sites other than the 16 alpha position. The resulting [1,7,16-3H]progesterone was added to a reconstituted enzyme system containing cytochrome P-450 form 3b, NADPH-cytochrome P-450 reductase, and NADPH, and the rate of 16 alpha-hydroxylation was measured by the formation of 3H2O. This reaction was shown to be linear with respect to time and to the cytochrome P-450 concentration. An apparent tritium isotope effect of 2.1 was observed by comparison of the rates of formation of tritium oxide and 16 alpha-hydroxyprogesterone, and the magnitude of the isotope effect was confirmed by an isotope competition assay in which a mixture of [1,7,16-3H]progesterone and [4-14C]progesterone was employed.
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pubmed:grant | |
pubmed:language |
eng
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pubmed:journal | |
pubmed:citationSubset |
IM
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pubmed:chemical |
http://linkedlifedata.com/resource/pubmed/chemical/16-hydroxyprogesterone,
http://linkedlifedata.com/resource/pubmed/chemical/Aryl Hydrocarbon Hydroxylases,
http://linkedlifedata.com/resource/pubmed/chemical/CYP2C3 protein, Oryctolagus...,
http://linkedlifedata.com/resource/pubmed/chemical/Carbon Radioisotopes,
http://linkedlifedata.com/resource/pubmed/chemical/Cytochrome P-450 Enzyme System,
http://linkedlifedata.com/resource/pubmed/chemical/Hydroxyprogesterones,
http://linkedlifedata.com/resource/pubmed/chemical/Progesterone,
http://linkedlifedata.com/resource/pubmed/chemical/Steroid 16-alpha-Hydroxylase,
http://linkedlifedata.com/resource/pubmed/chemical/Tritium
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pubmed:status |
MEDLINE
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pubmed:month |
Aug
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pubmed:issn |
0003-2697
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pubmed:author | |
pubmed:issnType |
Print
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pubmed:day |
1
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pubmed:volume |
164
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
355-61
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pubmed:dateRevised |
2007-11-14
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pubmed:meshHeading |
pubmed-meshheading:3674383-Animals,
pubmed-meshheading:3674383-Aryl Hydrocarbon Hydroxylases,
pubmed-meshheading:3674383-Carbon Radioisotopes,
pubmed-meshheading:3674383-Cytochrome P-450 Enzyme System,
pubmed-meshheading:3674383-Hydroxylation,
pubmed-meshheading:3674383-Hydroxyprogesterones,
pubmed-meshheading:3674383-Microsomes, Liver,
pubmed-meshheading:3674383-Progesterone,
pubmed-meshheading:3674383-Rabbits,
pubmed-meshheading:3674383-Radiometry,
pubmed-meshheading:3674383-Steroid 16-alpha-Hydroxylase,
pubmed-meshheading:3674383-Tritium
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pubmed:year |
1987
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pubmed:articleTitle |
Radiometric assay for cytochrome P-450-catalyzed progesterone 16 alpha-hydroxylation and determination of an apparent isotope effect.
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pubmed:affiliation |
Department of Biological Chemistry, Medical School, University of Michigan, Ann Arbor 48109.
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pubmed:publicationType |
Journal Article,
In Vitro,
Research Support, U.S. Gov't, P.H.S.
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