Butane monooxygenase of 'Pseudomonas butanovora':: purification and biochemical characterization of a terminal-alkane hydroxylating diiron monooxygenase
Butane monooxygenase of 'Pseudomonas butanovora':: purification and biochemical characterization of a terminal-alkane hydroxylating diiron monooxygenase
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DOI：
10.1099/mic.0.2006/004960-0
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发表时间：
2007-06-01
期刊：
影响因子：
2.8
通讯作者：
Arp, Daniel J.
中科院分区：
文献类型：
--
作者：
Dubbels, Bradley L.;Sayavedra-Soto, Luis A.;Arp, Daniel J.
丁烷单加氧酶(SBMO)是从革兰氏阴性β-变形杆菌中分离纯化的一种三组分二铁单加氧酶。重组酶复合体氧化C-3-C-6直链和支链脂肪烷烃，是‘P.butanovora’的生长底物。SBMO复合体由一个含铁羟基酶(BMOH)、一个黄铁硫磺NADH氧化还原酶(BMOR)和一个小调节成分蛋白(BMOB)组成。SBMO的物理性质与可溶性多组分二铁单氧合酶的sMMO家族非常相似。然而，在底物存在和产物分布的情况下，sBMO的催化性能在数量上是不同的。在H_2O_2和乙烯(称为过氧化氢分流)的作用下，BMOH具有氧化乙烯的能力，但这一活性至少比麦冬青霉OB3b的sMMO羟基酶活性低三个数量级。在没有BMOB的情况下，BMOH和BMOR在反应速度和产物产率方面是有效的。SBMO的区域特异性强烈偏向伯羟化，-gt；=80%的羟化发生在末端碳原子上。
Butane monooxygenase (sBMO) has been purified to homogeneity from the Gram-negative beta-proteobacterium 'Pseudomonas butanovora' and confirmed to be a three-component diiron monooxygenase system. The reconstituted enzyme complex oxidized C-3-C-6 linear and branched aliphatic alkanes, which are growth substrates for 'P. butanovora'. The sBMO complex was composed of an iron-containing hydroxylase (BMOH), a flavo-iron sulfur-containing NADH-oxidoreductase (BMOR) and a small regulatory component protein (BMOB). The physical characteristics of sBMO were remarkably similar to the sMMO family of soluble multicomponent diiron monooxgenases. However, the catalytic properties of sBMO were quantitatively different in regard to inactivation in the presence of substrate and product distribution. BMOH was capable of ethene oxidation when supplied with H2O2 and ethene (known as the peroxide shunt), but this activity was at least three orders of magnitude less than that observed for the hydroxylase of sMMO of Methylosinus trichosporium OB3b. BMOH and BMOR were efficient in the oxidation of ethene in the absence of BMOB with regard to rate of reaction and product yield. Regiospecificity of sBMO was strongly biased towards primary hydroxylation, with >= 80 % of the hydroxylations occurring at the terminal carbon atom.