A novel vanadium reductase, Vanabin2, forms a possible cascade involved in electron transfer
A novel vanadium reductase, Vanabin2, forms a possible cascade involved in electron transfer
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DOI：
10.1016/j.bbapap.2009.01.007
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发表时间：
2009-04-01
影响因子：
3.2
通讯作者：
Michibata, Hitoshi
中科院分区：
文献类型：
--
作者：
Kawakami, Norifumi;Ueki, Tatsuya;Michibata, Hitoshi
不寻常的能力，积累高水平的钒离子的浓度高达350毫米，10（7）倍的增加，在海水中发现，一直吸引了世纪的跨学科的关注。在海鞘钒细胞中，积累的V-V最终通过V-IV还原为V-III。因此，还原剂必须参与还原。在此之前，我们发现了一种钒结合蛋白Vanabin 2，其中所有18个半胱氨酸形成9个二硫键。在这里，我们报告说，Vanabin 2是一种新的钒还原酶，因为它的二硫键的部分切割的结果，在V-V还原为V-IV。我们建议，Vanabin 2形成一个可能的电子传递级联从电子供体，NADPH，通过谷胱甘肽还原酶，谷胱甘肽，和Vanabin 2的受体，和钒离子通过硫醇二硫键交换反应共轭。(C)2009 Elsevier B. V.保留所有权利。
The unusual ascidian ability to accumulate high levels of vanadium ions at concentrations of up to 350 mM, a 10(7)-fold increase over that found in seawater, has been attracting interdisciplinary attention for a century. Accumulated V-V is finally reduced to V-III via V-IV in ascidian vanadocytes. Reducing agents must therefore participate in the reduction. Previously, we identified a vanadium-binding protein, Vanabin2, in which all 18 cysteines form nine disulfide bonds. Here, we report that Vanabin2 is a novel vanadium reductase because partial cleavage of its disulfide bonds results in the reduction of V-V to V-IV. We propose that Vanabin2 forms a possible electron transfer cascade from the electron donor, NADPH, via glutathione reductase, glutathione, and Vanabin2 to the acceptor, and vanadium ions conjugated through thioldisulfide exchange reactions. (C) 2009 Elsevier B.V. All rights reserved.