Inhibition of catechol 2,3-dioxygenase from Pseudomonas putida by 3-chlorocatechol
| Autor: | G M Klecka, D T Gibson |
|---|---|
| Rok vydání: | 1981 |
| Předmět: |
Oxygenase
Catechols Chlorobenzenes Applied Microbiology and Biotechnology Catechol 2 3-Dioxygenase Dioxygenases chemistry.chemical_compound Dioxygenase Pseudomonas Ferrous Compounds Catechol oxidase chemistry.chemical_classification Catechol Tiron Ecology biology Chemistry Substrate (chemistry) biology.organism_classification Pseudomonas putida Dithiothreitol Kinetics Enzyme Biochemistry 1 2-Dihydroxybenzene-3 5-Disulfonic Acid Disodium Salt Oxygenases biology.protein Research Article Food Science Biotechnology |
| Zdroj: | Applied and Environmental Microbiology. 41:1159-1165 |
| ISSN: | 1098-5336 0099-2240 |
| DOI: | 10.1128/aem.41.5.1159-1165.1981 |
| Popis: | Partially purified preparations of catechol 2,3-dioxygenase from toluene-grown cells of Pseudomonas putida catalyzed the stoichiometric oxidation of 3-methylcatechol to 2-hydroxy-6-oxohepta-2,4-dienoate. Other substrates oxidized by the enzyme preparation were catechol, 4-methylcatechol, and 4-fluorocatechol. The apparent Michaelis constants for 3-methylcatechol and catechol were 10.6 and 22.0 muM, respectively. Substitution at the 4-position decreases the affinity and activity of the enzyme for the substrate. Catechol 2,3-dioxygenase preparations did not oxidize 3-chlorocatechol. In addition, incubation of the enzyme with 3-chlorocatechol led to inactivation of the enzyme. Kinetic analyses revealed that both 3-chlorocatechol and 4-chlorocatechol were noncompetitive or mixed-type inhibitors of the enzyme. 3-Chlorocatechol (Ki = 0.14 muM) was a more potent inhibitor than 4-chlorocatechol (Ki = 50 muM). The effect of the ion-chelating agents Tiron and o-phenanthrolene were compared with that of 3-chlorocatechol on the inactivation of the enzyme. Each inhibitor appeared to remove iron from the enzyme, since inactive enzyme preparations could be fully reactivated by treatment with ferrous iron and a reducing agent. |
| Databáze: | OpenAIRE |
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