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Predicate | Object |
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rdf:type | |
lifeskim:mentions | |
pubmed:issue |
1
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pubmed:dateCreated |
1987-6-1
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pubmed:abstractText |
The last step of (+)-geodin biosynthesis is a phenol oxidative coupling, which is one of the most important reactions in biosynthesis of natural products. The enzyme named dihydrogeodin oxidase catalyzes the regio- and stereospecific phenol oxidative coupling reaction to form (+)-geodin from dihydrogeodin. The enzyme was purified from the cell-free extract of Aspergillus terreus, a (+)-geodin producer, by ammonium sulfate fractionation, acid treatment, and column chromatographies on DEAE-cellulose, Hydroxyapatite, chromatofocusing, and Toyopearl HW-55S. The purified enzyme was homogeneous as judged by sodium dodecyl sulfate polyacrylamide gel electrophoresis. The molecular weight of the enzyme was estimated to be 153,000 by gel filtration on a Toyopearl HW-55S column and 76,000 by SDS-polyacrylamide gel electrophoresis, indicating that the enzyme is a dimer. The purified enzyme showed an intense blue color and had absorption maxima at 280 and 600 nm, which suggested it to be a blue copper protein. The copper content was found to be 8 atoms per subunit by atomic absorption analysis and no significant amount of other metals was detected by ICP emission spectrometry. The electron paramagnetic resonance spectrum showed the presence of type 1 and type 2 copper atoms in the enzyme molecule. Sodium azide and ethylxanthate inhibited the enzyme activity, but potassium cyanide and diethyldithiocarbamate, both known as potent copper enzyme inhibitors, were not inhibitory.
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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 |
0021-924X
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pubmed:author | |
pubmed:issnType |
Print
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pubmed:volume |
101
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
11-8
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pubmed:dateRevised |
2007-12-19
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pubmed:meshHeading |
pubmed-meshheading:3032923-Aspergillus,
pubmed-meshheading:3032923-Benzofurans,
pubmed-meshheading:3032923-Copper,
pubmed-meshheading:3032923-Electron Spin Resonance Spectroscopy,
pubmed-meshheading:3032923-Electrophoresis, Polyacrylamide Gel,
pubmed-meshheading:3032923-Molecular Weight,
pubmed-meshheading:3032923-Oxidoreductases,
pubmed-meshheading:3032923-Spectrophotometry,
pubmed-meshheading:3032923-Substrate Specificity
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pubmed:year |
1987
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pubmed:articleTitle |
Purification and properties of dihydrogeodin oxidase from Aspergillus terreus.
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pubmed:publicationType |
Journal Article
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