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rdf:type |
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lifeskim:mentions |
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pubmed:issue |
1
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pubmed:dateCreated |
1978-12-2
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pubmed:abstractText |
1. The influence of halogen substituents on the 1,2-dioxygenation of catechols was investigated. The results obtained with the two isoenzymes pyrocatechase I and pyrocatechase II from the haloarene-utilizing Pseudomonas sp. B 13 and the pyrocatechase from benzoate-induced cells of Alcaligenes eutrophus B.9 were compared. 2. Substituents on catechol were found to interfere with O2 binding by the two isoenzymes from Pseudomonas sp. B 13, whereas the Km value for catechol kept constant at different O2 concentrations. 3. Electron-attracting substituents decreased the Km values for catechols. 4. Results from binding studies with substituted catechols demonstrated narrow stereospecificities of pyrocatechase I from pseudomonas sp. B 13 and the pyrocatechase from alcaligenes eutrophus B.9. In contrast, a low steric hindrance by substituents in the binding of catechols with pyrocatechase II was observed. 5. Low pK'1 values of substituted catechols resulted in low Michaelis constants. 6. Electron-attracting substituents such as halogen decreased the reaction rates of catechol 1,2-dioxygenation. The correlation of the Vmax. values observed with pyrocatechase II from Pseudomonas sp. B 13 with the substituent constant sigma+ (Okamoto--Brown equation) was distinctly greater than with Hammett's sigma values. The corresponding logVmax. against sigma+ correlation for pyrocatechase I was considerably disturbed by steric influences of the substituents.
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pubmed:commentsCorrections |
http://linkedlifedata.com/resource/pubmed/commentcorrection/697766-14056355,
http://linkedlifedata.com/resource/pubmed/commentcorrection/697766-14363109,
http://linkedlifedata.com/resource/pubmed/commentcorrection/697766-238971,
http://linkedlifedata.com/resource/pubmed/commentcorrection/697766-4537396,
http://linkedlifedata.com/resource/pubmed/commentcorrection/697766-4613149,
http://linkedlifedata.com/resource/pubmed/commentcorrection/697766-4687392,
http://linkedlifedata.com/resource/pubmed/commentcorrection/697766-4852192,
http://linkedlifedata.com/resource/pubmed/commentcorrection/697766-4852581,
http://linkedlifedata.com/resource/pubmed/commentcorrection/697766-4950664,
http://linkedlifedata.com/resource/pubmed/commentcorrection/697766-5113598,
http://linkedlifedata.com/resource/pubmed/commentcorrection/697766-5123884,
http://linkedlifedata.com/resource/pubmed/commentcorrection/697766-5123888,
http://linkedlifedata.com/resource/pubmed/commentcorrection/697766-5597305,
http://linkedlifedata.com/resource/pubmed/commentcorrection/697766-5683506,
http://linkedlifedata.com/resource/pubmed/commentcorrection/697766-58860,
http://linkedlifedata.com/resource/pubmed/commentcorrection/697766-6011,
http://linkedlifedata.com/resource/pubmed/commentcorrection/697766-697765,
http://linkedlifedata.com/resource/pubmed/commentcorrection/697766-765127,
http://linkedlifedata.com/resource/pubmed/commentcorrection/697766-791073,
http://linkedlifedata.com/resource/pubmed/commentcorrection/697766-892
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pubmed:language |
eng
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pubmed:journal |
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pubmed:citationSubset |
IM
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pubmed:chemical |
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pubmed:status |
MEDLINE
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pubmed:month |
Jul
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pubmed:issn |
0264-6021
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pubmed:author |
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pubmed:issnType |
Print
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pubmed:day |
15
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pubmed:volume |
174
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
85-94
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pubmed:dateRevised |
2009-11-18
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pubmed:meshHeading |
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pubmed:year |
1978
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pubmed:articleTitle |
Chemical structure and biodegradability of halogenated aromatic compounds. Substituent effects on 1,2-dioxygenation of catechol.
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pubmed:publicationType |
Journal Article
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