title: Ability of bacterial biphenyl dioxygenases from Burkholderia sp. LB400 and Comamonas testosteroni B-356 to catalyse oxygenation of ortho-hydroxychlorobiphenyls formed from PCBs by plants.
abstract: Capacity of enzymes of the biphenyl/chlorobiphenyl pathway, especially biphenyl dioxygenase (BPDO) of two polychlorinated biphenyls (PCB) degrading bacteria, Burkholderia sp. LB400 and Comamonas testosteroni B-356, to metabolize ortho-substituted hydroxybiphenyls was tested.,These compounds found among plant products of PCB metabolism, are carrying chlorine atoms on the hydroxyl-substituted ring. The abilities of His-tagged purified LB400 and B-356 BPDOs to catalyze the oxygenation of 2-hydroxy-3-chlorobiphenyl, 2-hydroxy-5-chlorobiphenyl and 2-hydroxy-3,5-dichlorobiphenyl were compared. Both enzyme preparations catalyzed the hydroxylation of the three chloro-hydroxybiphenyls on the non-substituted ring. Neither LB400 BPDO nor B-356 BPDO oxygenated the substituted ring of the ortho-hydroxylated biphenyl. The fact that metabolites generated by both enzymes were identical for all three hydroxychlorobiphenyls tested; exclude any other mode of attack of these compounds by LB400 BPDOs than the ortho-meta oxygenation.
authors.affiliation: Department of Biochemistry and Microbiology, Faculty of Food and Biochemical Technology, ICT Prague, Technicka 3, 6, 166 28, Prague, Czech Republic.
authors.forename: K
authors.initials: K
authors.lastname: Francova
authors.forename: M
authors.initials: M
authors.lastname: Macková
authors.forename: T
authors.initials: T
authors.lastname: Macek
authors.forename: M
authors.initials: M
authors.lastname: Sylvestre
mesh_terms: D001673:Biodegradation, Environmental; D019117:Burkholderia / Q000201:enzymology; D002384:Catalysis; D020604:Comamonas testosteroni / Q000201:enzymology; D006090:Gram-Negative Bacteria / Q000201:enzymology*; D010084:Oxidation-Reduction; D010105:Oxygenases / Q000378:metabolism*; D010944:Plants / Q000378:metabolism*; D011078:Polychlorinated Biphenyls / Q000378:metabolism*; D012989:Soil Pollutants / Q000378:metabolism*
chemical_list: D012989:Soil Pollutants; D011078:Polychlorinated Biphenyls; D010105:Oxygenases; C092087:biphenyl-1,2-dioxygenase