ISSN:
1432-1327
Keywords:
Key words Horseradish peroxidase
;
Chlorophenols
;
Pollutant degradation
;
Metalloenzymes
;
Enzyme catalysis
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Chemistry and Pharmacology
Notes:
Abstract The well-known and easily available horseradish peroxidase (HRP) catalyzes the H2O2-dependent oxidative 4-dechlorination of the pollutant 2,4,6-trichlorophenol, which is recalcitrant to many organisms except those producing ligninases. UV-visible spectroscopy and gas chromatography-mass spectrometry identified the oxidized reaction product as 2,6-dichloro-1,4-benzoquinone. NMR and IR spectroscopic data further supported the above characterization. Experimental evidence for the elimination of HCl from the substrate was acquired by detecting the decrease in pH of the reaction mixture, and by observing the presence of the β-chlorocyclopentadienone cation fragment in the mass spectrum of 2,6-dichloro-1,4-benzoquinone. Consequently, nucleophilic attack by water on the 2,4,6-trichlorocyclohexadienone cation was proposed to give the final product. Our results indicate an oxidative dechlorination pathway catalyzed by HRP for 2,4,6-trichlorophenol, similar to that by extracellular lignin peroxidases. The relative catalytic efficiency of HRP seems higher than that of lignin peroxidases. The HRP-H2O2 catalytic system could be utilized in the degradation of polychlorinated phenols for industrial and biotechnological purposes.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/s007750050309
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