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Predicate | Object |
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rdf:type | |
lifeskim:mentions | |
pubmed:issue |
2
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pubmed:dateCreated |
1984-4-11
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pubmed:abstractText |
Pyridoxine-5-phosphate oxidase has been purified 2250-fold from pig brain by affinity chromatography. The enzyme of 60000 molecular weight is made up of two identical size subunits and binds 1 mol of FMN/mol dimer. 1 mol of the fluorescent inhibitor phospho-pyridoxal oxime interacts with 1 mol of the dimeric protein to yield a dissociation constant KD = 0.2 microM. Resolution of the holoenzyme into apoprotein and free FMN does not induce dissociation of the dimeric structure. The oxidase catalyzes the oxidation of the natural substrates pyridoxine 5-phosphate and pyridoxamine 5-phosphate, but phospho-pyridoxyl derivatives of the aromatic carboxylic acids, p-aminobenzoate and m-aminobenzoate, are also excellent substrates of the enzyme. Introduction of electron-withdrawing substituents into the structure of benzene increases the kcat values. A comparison of the kcat values obtained with several synthetic substrates suggests that electron-withdrawing substituents tend to stabilize carbanionic intermediates formed in the earlier stages of catalysis.
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pubmed:grant | |
pubmed:language |
eng
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pubmed:journal | |
pubmed:citationSubset |
IM
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pubmed:chemical | |
pubmed:status |
MEDLINE
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pubmed:month |
Jan
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pubmed:issn |
0014-2956
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pubmed:author | |
pubmed:issnType |
Print
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pubmed:day |
16
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pubmed:volume |
138
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
327-32
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pubmed:dateRevised |
2007-11-14
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pubmed:meshHeading |
pubmed-meshheading:6697989-Animals,
pubmed-meshheading:6697989-Binding Sites,
pubmed-meshheading:6697989-Brain,
pubmed-meshheading:6697989-Chromatography, Affinity,
pubmed-meshheading:6697989-Electrophoresis, Polyacrylamide Gel,
pubmed-meshheading:6697989-Flavin Mononucleotide,
pubmed-meshheading:6697989-Kinetics,
pubmed-meshheading:6697989-Molecular Weight,
pubmed-meshheading:6697989-Oxidoreductases Acting on CH-NH Group Donors,
pubmed-meshheading:6697989-Pyridoxaminephosphate Oxidase,
pubmed-meshheading:6697989-Spectrometry, Fluorescence,
pubmed-meshheading:6697989-Swine
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pubmed:year |
1984
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pubmed:articleTitle |
Brain pyridoxine-5-phosphate oxidase. A dimeric enzyme containing one FMN site.
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pubmed:publicationType |
Journal Article,
Research Support, U.S. Gov't, P.H.S.
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