Insights into unknown foreign ligand in copper nitrite reductase
Insights into unknown foreign ligand in copper nitrite reductase
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深入了解亚硝酸铜还原酶中未知的外来配体
DOI：
10.1016/j.bbrc.2015.07.025
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发表时间：
2015
期刊：
影响因子：
--
通讯作者：
Tsuyoshi Inoue
中科院分区：
文献类型：
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作者：
Yohta Fukuda;Tse Ka Man;Yuji Kado;Eiichi Mizohata;Hiroyoshi Matsumura;Tsuyoshi Inoue
双功能亚硝酸铜还原酶（CuNIR）催化亚硝酸盐还原为一氧化氮和双氧还原为过氧化氢。与研究充分的亚硝酸盐还原机制相反，CuNIR中的氧还原机制一直是完全未知的，因为单核铜-氧络合物很容易分解，它们的可视化一直是具有挑战性的。在这里，我们提供的光谱证据表明，外来配体结合到催化铜（T2 Cu）网站的CuNIR，并确定CuNIR结构显示T2 Cu上的双原子分子。这个未知的配体可以被解释为双氧，并可能提供洞察CuNIR的氧还原机制。
Bifunctional copper nitrite reductase (CuNIR) catalyzes nitrite reduction to nitric oxide and dioxygen reduction to hydrogen peroxide. In contrast to the well-researched nitrite reduction mechanism, the oxygen reduction mechanism in CuNIR has been totally unknown, because mononuclear copper–oxygen complexes decompose so readily that their visualization has been challenging. Here, we provide spectroscopic evidence that a foreign ligand binds to the catalytic copper (T2Cu) site of CuNIR, and determine CuNIR structures displaying a diatomic molecule on T2Cu. This unknown ligand can be interpreted as dioxygen and may provide insights into the oxygen reduction mechanism of CuNIR.