Torok D S, Resnick S M, Brand J M, Cruden D L, Gibson D T
Department of Microbiology, College of Medicine, University of Iowa, Iowa City 52242, USA.
J Bacteriol. 1995 Oct;177(20):5799-805. doi: 10.1128/jb.177.20.5799-5805.1995.
Bacterial strains expressing toluene and naphthalene dioxygenase were used to examine the sequence of reactions involved in the oxidation of 1,2-dihydronaphthalene. Toluene dioxygenase of Pseudomonas putida F39/D oxidizes 1,2-dihydronaphthalene to (+)-cis-(1S,2R)-dihydroxy-1,2,3,4-tetrahydronaphthalene, (+)-(1R)-hydroxy-1,2-dihydronaphthalene, and (+)-cis-(1R,2S)-dihydroxy-1,2-dihydronaphthalene. In contrast, naphthalene dioxygenase of Pseudomonas sp. strain NCIB 9816/11 oxidizes 1,2-dihydronaphthalene to the opposite enantiomer, (-)-cis-(1R,2S)-dihydroxy-1,2,3,4-tetrahydronaphthalene and the identical (+)-cis-(1R,2S)-dihydroxy-1,2-dihydronaphthalene. Recombinant Escherichia coli strains expressing the structural genes for toluene and naphthalene dioxygenases confirmed the involvement of these enzymes in the reactions catalyzed by strains F39/D and NCIB 9816/11. 1-Hydroxy-1,2-dihydronaphthalene was not formed by strains expressing naphthalene dioxygenase. These results coupled with time course studies and deuterium labelling experiments indicate that, in addition to direct dioxygenation of the olefin, both enzymes have the ability to desaturate (dehydrogenate) 1,2-dihydronaphthalene to naphthalene, which serves as a substrate for cis dihydroxylation.
利用表达甲苯和萘双加氧酶的细菌菌株来研究1,2-二氢萘氧化过程中所涉及的反应顺序。恶臭假单胞菌F39/D的甲苯双加氧酶将1,2-二氢萘氧化为(+)-顺式-(1S,2R)-二羟基-1,2,3,4-四氢萘、(+)-(1R)-羟基-1,2-二氢萘和(+)-顺式-(1R,2S)-二羟基-1,2-二氢萘。相比之下，假单胞菌属菌株NCIB 9816/11的萘双加氧酶将1,2-二氢萘氧化为对映体(-)-顺式-(1R,2S)-二羟基-1,2,3,4-四氢萘以及相同的(+)-顺式-(1R,2S)-二羟基-1,2-二氢萘。表达甲苯和萘双加氧酶结构基因的重组大肠杆菌菌株证实了这些酶参与了F39/D菌株和NCIB 9816/11菌株所催化的反应。表达萘双加氧酶的菌株未形成1-羟基-1,2-二氢萘。这些结果与时间进程研究以及氘标记实验表明，除了烯烃的直接双加氧作用外，这两种酶都有能力将1,2-二氢萘去饱和（脱氢）为萘，而萘可作为顺式二羟基化的底物。
