Structural and spectroscopic characterization of CO inhibition of [NiFe]-hydrogenase from Citrobacter sp. S-77
Structural and spectroscopic characterization of CO inhibition of [NiFe]-hydrogenase from Citrobacter sp. S-77
复制标题
柠檬酸杆菌属 [NiFe]-氢化酶的 CO 抑制的结构和光谱表征。
DOI：
10.1107/s2053230x22000188
复制
发表时间：
2022
期刊：
影响因子：
--
通讯作者：
Higuchi Yoshiki
中科院分区：
文献类型：
--
作者：
Imanishi Takahiro;Nishikawa Koji;Taketa Midori;Higuchi Katsuhiro;Tai Hulin;Hirota Shun;Hojo Hironobu;Kawakami Toru;Hataguchi Kiriko;Matsumoto Kayoko;Ogata Hideaki;Higuchi Yoshiki
氢化酶催化H2的可逆氧化。一氧化碳（CO）是O2-敏感[NiFe]-氢化酶的竞争性抑制剂。虽然一些耐O2的[NiFe]-氢化酶的活性不受CO的影响，但部分耐O2的[NiFe]-氢化酶柠檬酸杆菌S-77（S77-HYB）被CO抑制。电子顺磁共振光谱显示抗磁性Ni 2+状态，和傅立叶变换红外光谱揭示了外源CO配体的伸缩振动。在1.77 nm处测定的晶体结构表明，CO与S77-HYB的Ni-Fe活性中心的镍离子弱结合。 这些结果表明，[NiFe]-氢化酶的O2和CO耐受性之间呈正相关。
Hydrogenases catalyze the reversible oxidation of H2. Carbon monoxide (CO) is known to be a competitive inhibitor of O2-sensitive [NiFe]-hydrogenases. Although the activities of some O2-tolerant [NiFe]-hydrogenases are unaffected by CO, the partially O2-tolerant [NiFe]-hydrogenase from Citrobacter sp. S-77 (S77-HYB) is inhibited by CO. In this work, the CO-bound state of S77-HYB was characterized by activity assays, spectroscopic techniques and X-ray crystallography. Electron paramagnetic resonance spectroscopy showed a diamagnetic Ni2+ state, and Fourier-transform infrared spectroscopy revealed the stretching vibration of the exogenous CO ligand. The crystal structure determined at 1.77 Å resolution revealed that CO binds weakly to the nickel ion in the Ni–Fe active site of S77-HYB. These results suggest a positive correlation between O2 and CO tolerance in [NiFe]-hydrogenases.