Peroxygenase and oxidase activities of dehaloperoxidase-hemoglobin from Amphitrite ornata.
Peroxygenase and oxidase activities of dehaloperoxidase-hemoglobin from Amphitrite ornata.
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DOI：
10.1021/ja500293c
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发表时间：
2014-06-04
影响因子：
15
通讯作者：
Ghiladi, Reza A.
中科院分区：
文献类型：
--
作者：
Barrios, David A.;D'Antonio, Jennifer;McCombs, Nikolette L.;Zhao, Jing;Franzen, Stefan;Schmidt, Andreas C.;Sombers, Leslie A.;Ghiladi, Reza A.
海洋珠蛋白脱卤过氧化物酶-血红蛋白（DHP）从Amphitrite ornata被发现催化H2 O2依赖的氧化monohalindoles，一个以前未知的类DHP的底物。以5-Br-吲哚为代表底物，发现主要的单氧化产物为5-Br-2-oxindole和5-Br-3-oxindolenine。同位素标记的研究证实，氧原子纳入完全来自H2 O2，以前未报道的过氧合酶活性的DHP的指示。过氧化物酶活性可以从铁或含氧亚铁状态开始，具有相等的底物转化和产物分布。结果发现，5-Br-3-oxindolenine的前体5-Br-3-oxindole，很容易还原铁酶的氧亚铁状态，表现出不寻常的产品驱动的酶的还原。因此，在过氧合酶活性停止后，DHP返回到球蛋白活性的含氧亚铁形式。在无H2 O2存在下与5-Br-3-oxindole的反应也产生了5，5 ′-Br 2-靛蓝，高于有氧条件下预期的反应化学计量，O2浓度研究证明了分子氧消耗。非酶和厌氧对照均证实了在催化生成5，5 ′-Br 2-靛蓝中对DHP和分子氧的需求，并共同表明了新鉴定的DHP氧化酶活性。
The marine globin dehaloperoxidase-hemoglobin (DHP) from Amphitrite ornata was found to catalyze the H2O2-dependent oxidation of monohaloindoles, a previously unknown class of substrate for DHP. Using 5-Br-indole as a representative substrate, the major monooxygenated products were found to be 5-Br-2-oxindole and 5-Br-3-oxindolenine. Isotope labeling studies confirmed that the oxygen atom incorporated was derived exclusively from H2O2, indicative of a previously unreported peroxygenase activity for DHP. Peroxygenase activity could be initiated from either the ferric or oxyferrous states with equivalent substrate conversion and product distribution. It was found that 5-Br-3-oxindole, a precursor of the product 5-Br-3-oxindolenine, readily reduced the ferric enzyme to the oxyferrous state, demonstrating an unusual product-driven reduction of the enzyme. As such, DHP returns to the globin-active oxyferrous form after peroxygenase activity ceases. Reactivity with 5-Br-3-oxindole in the absence of H2O2 also yielded 5,5′-Br2-indigo above the expected reaction stoichiometry under aerobic conditions, and O2-concentration studies demonstrated dioxygen consumption. Nonenzymatic and anaerobic controls both confirmed the requirements for DHP and molecular oxygen in the catalytic generation of 5,5′-Br2-indigo, and together suggest a newly identified oxidase activity for DHP.
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影响因子：
2.9
作者：
D'Antonio, Jennifer;D'Antonio, Edward L.;Ghiladi, Reza A.
通讯作者：
Ghiladi, Reza A.
影响因子：
2.9
作者：
D'Antonio, Jennifer;Ghiladi, Reza A.
通讯作者：
Ghiladi, Reza A.
DOI：
10.1107/s0907444910014605
发表时间：
2010-07-01
影响因子：
2.2
作者：
de Serrano, V. S.;Davis, M. F.;Franzen, S.
通讯作者：
Franzen, S.
DOI：
10.1107/s0907444910004580
发表时间：
2010-05-01
影响因子：
2.2
作者：
de Serrano, Vesna;D'Antonio, Jennifer;Ghiladi, Reza A.
通讯作者：
Ghiladi, Reza A.
影响因子：
2.9
作者：
de Serrano, Vesna;Franzen, Stefan
通讯作者：
Franzen, Stefan