Publications

• Purification and characterization of a catechol 1,2-dioxygenase from a phenol degrading Candida albicans TL3.

  Tsai S.-C., Li Y.-K.

  A eukaryotic catechol 1,2-dioxygenase (1,2-CTD) was produced from a Candida albicans TL3 that possesses high tolerance for phenol and strong phenol degrading activity. The 1,2-CTD was purified via ammonium sulfate precipitation, Sephadex G-75 gel filtration, and HiTrap Q Sepharose column chromatog ... >> More

  A eukaryotic catechol 1,2-dioxygenase (1,2-CTD) was produced from a Candida albicans TL3 that possesses high tolerance for phenol and strong phenol degrading activity. The 1,2-CTD was purified via ammonium sulfate precipitation, Sephadex G-75 gel filtration, and HiTrap Q Sepharose column chromatography. The enzyme was purified to homogeneity and found to be a homodimer with a subunit molecular weight of 32,000. Each subunit contained one iron. The optimal temperature and pH were 25 degrees C and 8.0, respectively. Substrate analysis showed that the purified enzyme was a type I catechol 1,2-dioxygenase. This is the first time that a 1,2-CTD from a eukaryote (Candida albicans) has been characterized. Peptide sequencing on fragments of 1,2-CTD by Edman degradation and MALDI-TOF/TOF mass analyses provided information of amino acid sequences for BLAST analysis, the outcome of the BLAST revealed that this eukaryotic 1,2-CTD has high identity with a hypothetical protein, CaO19_12036, from Candida albicans SC5314. We conclude that the hypothetical protein is 1,2-CTD. << Less

  Arch. Microbiol. 187:199-206(2007) [PubMed] [EuropePMC]

• Influence of para-substituents on the oxidative metabolism of o-nitrophenols by Pseudomonas putida B2.

  Zeyer J., Kocher H.P., Timmis K.N.

  Pseudomonas putida B2 is able to grow on o-nitrophenol (ONP) as the sole source of carbon and nitrogen. ONP was converted by a nitrophenol oxygenase to nitrite and catechol. Catechol was then attacked by a catechol 1,2-dioxygenase and further degraded through an ortho-cleavage pathway. ONP derivat ... >> More

  Pseudomonas putida B2 is able to grow on o-nitrophenol (ONP) as the sole source of carbon and nitrogen. ONP was converted by a nitrophenol oxygenase to nitrite and catechol. Catechol was then attacked by a catechol 1,2-dioxygenase and further degraded through an ortho-cleavage pathway. ONP derivatives which were para-substituted with a methyl-, chloro-, carboxy-, formyl- or nitro-group failed to support growth of strain B2. Relevant catabolic enzymes were characterized to analyze why these derivatives were not mineralized. Nitrophenol oxygenase of strain B2 is a soluble, NADPH-dependent enzyme that is stimulated by magnesium, manganese, and calcium ions. It is active toward ONP, 4-methyl-, 4-chloro-, and to a lesser extent, 4-formyl-ONP but not toward 4-carboxy- or 4-nitro-ONP. In addition, 4-formyl-, 4-carboxy-, and 4-nitro-ONP failed to induce the formation of nitrophenol oxygenase. Catechol 1,2-dioxygenase of strain B2 is active toward catechol and 4-methyl-catechol but only poorly active toward chlorinated catechols. 4-Methyl-catechol is likely to be degraded to methyl-lactones, which are often dead-end metabolites in bacteria. Thus, of the compounds tested, only unsubstituted ONP acts as an inducer and substrate for all of the enzymes of a productive catabolic pathway. << Less

  Appl Environ Microbiol 52:334-339(1986) [PubMed] [EuropePMC]

  This publication is cited by 1 other entry.