title: Purification and properties of 2,3-dihydroxy-p-cumate-3,4-dioxygenase from Bacillus species.
abstract: 2,3-Dihydroxy-p-cumate-3,4-dioxygenase, an enzyme involved in the catabolism of p-cymene, was purified to homogeneity from Bacillus species by affinity chromatography. Purification of the dioxygenase allowed the observation of the immediate ring cleavage product of 2,3-dihydroxy-p-cumate. The enzyme was optimally active at pH 8.2 and at 35 degrees C. The Km value for 2,3-dihydroxy-p-cumate was 32 microM. The enzyme had a broad substrate specificity for 3-substituted catechols. The activity of the enzyme was inhibited by heavy metals, sulphydryl inhibitors, iron-chelating agents, and substrate analogues. Fe2+ was suggested as a cofactor.
authors.affiliation: Department of Chemistry, Karnatak University, Dharwad, India.
authors.forename: H Z
authors.initials: HZ
authors.lastname: Ninnekar
mesh_terms: D001407:Bacillus / Q000201:enzymology*; D002614:Chelating Agents / Q000494:pharmacology; D002846:Chromatography, Affinity; D049308:Dioxygenases; D004591:Electrophoresis, Polyacrylamide Gel; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008670:Metals / Q000494:pharmacology; D010105:Oxygenases / Q000037:antagonists & inhibitors / Q000302:isolation & purification* / Q000378:metabolism; D013379:Substrate Specificity; D013439:Sulfhydryl Reagents / Q000494:pharmacology; D013696:Temperature
chemical_list: D002614:Chelating Agents; D008670:Metals; D013439:Sulfhydryl Reagents; D010105:Oxygenases; C078267:2,3-dihydroxy-4-cumate-3,4-dioxygenase; D049308:Dioxygenases