An unusual dehalogenating peroxidase from the marine terebellid polychaete Amphitrite ornata.
The terebellid polychaete Amphitrite ornata produces no detectable volatile halogenated secondary metabolites, but frequently inhabits coastal marine sediments heavily contaminated with anthropogenic or biogenic haloaromatic compounds. This animal contains high levels of two very unusual enzymes, dehalogenating peroxidases. We have purified and partially characterized one of these dehaloperoxidases, DHP I. DHP I is a heme enzyme (Mr = 30,790) composed of two identical subunits (Mr = 15,529) and is very rich in the amino acids aspartic acid (+ asparagine) and glutamic acid (+ glutamine). The enzyme converts trihalogenated phenols, such as 2,4,6-tribromophenol, into dihalogenated quinones. The optimum pH for this reaction is 5.0. DHP I is also active against di- and monohalogenated phenols and will oxidize bromo-, chloro-, and fluorophenols. We have identified similar dehaloperoxidase activities in other infaunal polychaetes, including halometabolite-producing species.
Chen
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YP
Department of Biological Sciences, University of South Carolina, Columbia, South Carolina 29208, USA.
Woodin
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Lincoln
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Lovell
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D000596:Amino Acids / Q000032:analysis; D000818:Animals; D002848:Chromatography, DEAE-Cellulose; D002850:Chromatography, Gel; D004591:Electrophoresis, Polyacrylamide Gel; D006420:Hemeproteins / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism; D006454:Hemoglobins; D007700:Kinetics; D046911:Macromolecular Substances; D008970:Molecular Weight; D010544:Peroxidases / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism*; D011077:Polychaeta / Q000201:enzymology*; D013045:Species Specificity; D013379:Substrate Specificity
D000596:Amino Acids; D006420:Hemeproteins; D006454:Hemoglobins; D046911:Macromolecular Substances; C098661:DHP I dehaloperoxidase; D010544:Peroxidases