Activation process of [NiFe] hydrogenase elucidated by high-resolution X-ray analyses: Conversion of the ready to the unready state
Activation process of [NiFe] hydrogenase elucidated by high-resolution X-ray analyses: Conversion of the ready to the unready state
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DOI：
10.1016/j.str.2005.07.018
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发表时间：
2005-11-01
期刊：
影响因子：
5.7
通讯作者：
Higuchi, Y
中科院分区：
文献类型：
--
作者：
Ogata, H;Hirota, S;Higuchi, Y
氢化酶催化氢分子的氧化还原，在利用二氢作为能源方面具有潜在的应用前景。[NiFe]氢化酶有两种不同的氧化状态，Ni-A（未准备，在还原激活中表现为滞后期）和Ni-B（准备）。我们成功地利用Na2S和O-2将Ni-B转化为Ni-A，并确定了这两种状态的高分辨率晶体结构。Ni-B在Ni-Fe活性位点具有单原子非蛋白桥接配体，而Ni-A具有双原子。Ni-A桥接种的末端原子在CO络合物中与外源CO的C原子占据相似的位置（抑制状态）。提出了非准备态（Ni-A）和抑制态（CO配合物）酶结构的共同特征。这些发现为设计新的仿生二氢生产系统和燃料电池装置提供了有用的信息。
Hydrogenases catalyze oxidoreduction of molecular hydrogen and have potential applications for utilizing dihydrogen as an energy source. [NiFe] hydrogenase has two different oxidized states, Ni-A (unready, exhibits a lag phase in reductive activation) and Ni-B (ready). We have succeeded in converting Ni-B to Ni-A with the use of Na2S and O-2 and determining the high-resolution crystal structures of both states. Ni-B possesses a monatomic nonprotein bridging ligand at the Ni-Fe active site, whereas Ni-A has a diatomic: species. The terminal atom of the bridging species of Ni-A occupies a similar position as C of the exogenous CO in the CO complex (inhibited state). The common features of the enzyme structures at the unready (Ni-A) and inhibited (CO complex) states are proposed. These findings provide useful information on the design of new systems of biomimetic dihydrogen production and fuel cell devices.