The activation of the [NiFe]-hydrogenase from Allochromatium vinosum.: An infrared spectro-electrochemical study
The activation of the [NiFe]-hydrogenase from Allochromatium vinosum.: An infrared spectro-electrochemical study
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DOI：
10.1007/s00775-004-0570-z
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发表时间：
2004-09-01
影响因子：
3
通讯作者：
Albracht, SPJ
中科院分区：
文献类型：
--
作者：
Bleijlevens, B;van Broekhuizen, FA;Albracht, SPJ
膜结合[NiFe]-氢化酶从Allochromatium vinosum可以发生在几个非活性或活性状态。本研究首次系统地对A. vinosum酶，重点是非活性/活性过渡的光谱电化学性质。这种转变涉及能垒，这可以在高温下克服。还原的Ready酶可以以两种不同的非活性状态存在，它们处于明显的酸碱平衡中。有人提出，在Ni-Fe网站的桥接位置的羟基配体被质子化，形成的水分子随后被删除。这使得活性位点能够在桥接位置结合氢，从而形成酶的完全活性状态。它进一步表明，在酶的活性位点减少1巴H-2可以发生在三个不同的电子顺磁共振（EPR）沉默状态与不同程度的质子化。
The membrane-bound [NiFe]-hydrogenase from Allochromatium vinosum can occur in several inactive or active states. This study presents the first systematic infrared characterisation of the A. vinosum enzyme, with emphasis on the spectro-electrochemical properties of the inactive/active transition. This transition involves an energy barrier, which can be overcome at elevated temperatures. The reduced Ready enzyme can exist in two different inactive states, which are in an apparent acid-base equilibrium. It is proposed that a hydroxyl ligand in a bridging position in the Ni-Fe site is protonated and that the formed water molecule is subsequently removed. This enables the active site to bind hydrogen in a bridging position, allowing the formation of the fully active state of the enzyme. It is further shown that the active site in enzyme reduced by 1 bar H-2 can occur in three different electron paramagnetic resonance (EPR)-silent states with a different degree of protonation.