Haddock J D, Horton J R, Gibson D T
Department of Microbiology, University of Iowa, Iowa City 52242.
J Bacteriol. 1995 Jan;177(1):20-6. doi: 10.1128/jb.177.1.20-26.1995.
Oxidation of biphenyl and nine chlorinated biphenyls (CBs) by the biphenyl 2,3-dioxygenase from Pseudomonas sp. strain LB400 was examined. The purified terminal oxygenase required the addition of partially purified electron transport components, NAD(P)H, and ferrous iron to oxidize biphenyl and CBs. cis-Biphenyl 2,3-dihydrodiol was produced with biphenyl as the substrate. Dihydrodiols were produced from all CBs, and more than one compound was produced with most substrates. Catechols were produced when the dioxygenase-catalyzed reaction occurred at the 2,3 position of a 2-chlorophenyl ring, resulting in dechlorination of the substrate. Oxidation at the 3,4 position of a 2,5-dichlorophenyl ring produced a 3,4-dihydrodiol. Compounds resulting from both types of reaction were produced during oxidation of 2,5,2'-trichlorobiphenyl. The broad substrate specificity and the ability to oxidize at different ring positions suggest that the biphenyl 2,3-dioxygenase is responsible for the wide range of CBs oxidized by Pseudomonas sp. strain LB400.
研究了来自假单胞菌属菌株LB400的联苯2,3-双加氧酶对联苯和九种氯代联苯（CBs）的氧化作用。纯化后的末端加氧酶需要添加部分纯化的电子传递成分、NAD(P)H和亚铁离子才能氧化联苯和CBs。以联苯为底物时生成了顺式联苯2,3-二氢二醇。所有CBs都生成了二氢二醇，大多数底物生成了不止一种化合物。当双加氧酶催化的反应发生在2-氯苯基环的2,3位时生成了儿茶酚，导致底物脱氯。2,5-二氯苯基环的3,4位发生氧化生成了3,4-二氢二醇。在2,5,2'-三氯联苯的氧化过程中生成了两种反应类型的产物。广泛的底物特异性以及在不同环位进行氧化的能力表明，联苯2,3-双加氧酶是假单胞菌属菌株LB400氧化多种CBs的原因。
