Diverse oxygenations catalyzed by carbazole 1,9a-dioxygenase from Pseudomonas sp strain CA10
Diverse oxygenations catalyzed by carbazole 1,9a-dioxygenase from Pseudomonas sp strain CA10
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DOI：
10.1128/jb.181.10.3105-3113.1999
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发表时间：
1999-05-01
影响因子：
3.2
通讯作者：
Omori, T
中科院分区：
文献类型：
--
作者：
Nojiri, H;Nam, JW;Omori, T
假单胞菌的咔唑1，9a-双加氧酶(CARDO)菌株CA10是一种催化咔唑、二苯并呋喃和二苯并-对二恶英转角双氧化的多组份酶。气相色谱-质谱分析、H-1和C-13核磁共振分析表明，黄原烯和酚硫醚分别转化为2，2‘，3-三羟基二苯基甲烷和2，2’，3-三羟基二苯硫醚。因此，对于xanthene和phoxthiin，CARDO在与氧原子相邻的角位置发生角二加氧反应，生成杂环裂解化合物。此外，CARDO还催化多环芳烃和联苯的顺式双羟基化反应。以CARDO为催化剂，将萘和联苯分别转化为顺-1，2-二羟基-1，2-二氢萘和顺-2，3-二羟基-2，3-二氢联苯。另一方面，CARDO还催化二苯并噻吩硫杂原子单氧化制得二苯并噻吩环5-氧化物和9-羟基荧环。这些结果表明，CARDO具有广泛的底物范围，可以催化不同的氧合反应：角状双氧化、顺式双羟基化和单氧化。CARDO对几种芳香族化合物的不同催化氧化反应可能反映了底物与CARDO反应中心结合的差异。
Carbazole 1,9a-dioxygenase (CARDO) from Pseudomonas sp. strain CA10 is a multicomponent enzyme that catalyzes the angular dioxygenation of carbazole, dibenzofuran, and dibenzo-p-dioxin. It was revealed by gas chromatography-mass spectrometry and H-1 and C-13 nuclear magnetic resonance analyses that xanthene and phenoxathiin were converted to 2,2',3-trihydroxydiphenylmethane and 2,2',3-trihydroxydiphenyl sulfide, respectively. Thus, for xanthene and phenoxathiin, angular dioxygenation by CARDO occurred at the angular position adjacent to the oxygen atom to yield hetero ring-cleaved compounds. In addition to the angular dioxygenation, CARDO catalyzed the cis dihydroxylation of polycyclic aromatic hydrocarbons and biphenyl. Naphthalene and biphenyl were converted by CARDO to cis-1,2-dihydroxy-1,2-dihydronaphthalene and cis-2,3-dihydroxy-2,3-dihydrobiphenyl, respectively. On the other hand, CARDO also catalyzed the monooxygenation of sulfur heteroatoms in dibenzothiophene and of the benzylic methylenic group in fluorene to yield dibenzothiophene-5-oxide and 9-hydroxyfluorene, respectively. These results indicate that CARDO has a broad substrate range and can catalyze diverse oxygenation: angular dioxygenation, cis dihydroxylation, and monooxygenation. The diverse oxygenation catalyzed by CARDO for several aromatic compounds might reflect the differences in the binding of the substrates to the reaction center of CARDO.