Ferrari R P, Laurenti E, Trotta F
Dipartimento di Chimica I.F.M., Università di Torino, Italy.
J Biol Inorg Chem. 1999 Apr;4(2):232-7. doi: 10.1007/s007750050309.
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 beta-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.
著名且易于获取的辣根过氧化物酶（HRP）催化污染物2,4,6 - 三氯苯酚的H2O2依赖性氧化脱氯反应，除了那些产生木质素酶的生物外，许多生物对该污染物具有抗性。紫外可见光谱和气相色谱 - 质谱法鉴定氧化反应产物为2,6 - 二氯 - 1,4 - 苯醌。核磁共振和红外光谱数据进一步支持了上述表征。通过检测反应混合物pH值的降低以及观察2,6 - 二氯 - 1,4 - 苯醌质谱中β - 氯环戊二烯酮阳离子碎片的存在，获得了从底物中消除HCl的实验证据。因此，提出水对2,4,6 - 三氯环己二烯酮阳离子的亲核攻击产生最终产物。我们的结果表明HRP催化2,4,6 - 三氯苯酚的氧化脱氯途径，类似于细胞外木质素过氧化物酶催化的途径。HRP的相对催化效率似乎高于木质素过氧化物酶。HRP - H2O2催化体系可用于工业和生物技术目的的多氯苯酚降解中。
