Trapping an Oxidized and Protonated Intermediate of the [FeFe]-Hydrogenase Cofactor under Mildly Reducing Conditions.
Trapping an Oxidized and Protonated Intermediate of the [FeFe]-Hydrogenase Cofactor under Mildly Reducing Conditions.
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在温和还原条件下捕获[FeFe]-氢化酶辅因子的氧化和质子化中间体。
DOI：
10.1021/acs.inorgchem.2c00954
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发表时间：
2022
影响因子：
4.6
通讯作者：
S. Stripp
中科院分区：
文献类型：
--
作者：
Moritz Senger;J. Duan;M. Pavliuk;Ulf‐Peter Apfel;M. Haumann;S. Stripp
氢簇是[FeFe]-氢化酶的催化辅因子，[FeFe]-氢化酶是一种催化二氢（H2）形成的金属酶。氢簇的催化二铁位点携带两个氰化物和三个一氧化碳配体，使其成为红外光谱的优良目标。在以前的工作中，我们确定了一个氧化和质子化的H-簇物种，其红外特征不同于氧化的静息态（Hox）的一个小的，但明显的位移到更高的频率。这种"蓝移"是由质子化在[4Fe-4S] subcomplex的H-集群。该新物种，表示HoxH，优先积累在低pH值和外源性还原剂连二亚硫酸钠（NaDT）的存在下。当HoxH与H2反应时，形成氢化物状态（Hhyd），这是[FeFe]-氢化酶周转的关键中间体。最近的出版物重新审视了我们的协议的积累HoxH在野生型[FeFe]-氢化酶，结论是抑制NaDT衰变产物，而不是辅因子质子化导致光谱的“蓝移”。在这里，我们表明，HoxH的形成不需要存在的NaDT（或其衰变产物），但积累也与温和的还原剂三（2-羧乙基）膦，二硫苏糖醇，或抗坏血酸，特别是在低pH值。我们的数据一致表明，HoxH积累时，H-簇的去质子化受损，从而防止恢复的氧化静息态Hox的催化循环。
The H-cluster is the catalytic cofactor of [FeFe]-hydrogenase, a metalloenzyme that catalyzes the formation of dihydrogen (H2). The catalytic diiron site of the H-cluster carries two cyanide and three carbon monoxide ligands, making it an excellent target for IR spectroscopy. In previous work, we identified an oxidized and protonated H-cluster species, whose IR signature differs from that of the oxidized resting state (Hox) by a small but distinct shift to higher frequencies. This "blue shift" was explained by a protonation at the [4Fe-4S] subcomplex of the H-cluster. The novel species, denoted HoxH, was preferentially accumulated at low pH and in the presence of the exogenous reductant sodium dithionite (NaDT). When HoxH was reacted with H2, the hydride state (Hhyd) was formed, a key intermediate of [FeFe]-hydrogenase turnover. A recent publication revisited our protocol for the accumulation of HoxH in wild-type [FeFe]-hydrogenase, concluding that inhibition by NaDT decay products rather than cofactor protonation causes the spectroscopic "blue shift". Here, we demonstrate that HoxH formation does not require the presence of NaDT (or its decay products), but accumulates also with the milder reductants tris(2-carboxyethyl)phosphine, dithiothreitol, or ascorbic acid, in particular at low pH. Our data consistently suggest that HoxH is accumulated when deprotonation of the H-cluster is impaired, thereby preventing the regain of the oxidized resting state Hox in the catalytic cycle.
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DOI：
10.1002/anie.201801914
发表时间：
2018-05-04
期刊：
Angewandte Chemie (International ed. in English)
影响因子：
--
作者：
Sommer C;Richers CP;Lubitz W;Rauchfuss TB;Reijerse EJ
通讯作者：
Reijerse EJ
DOI：
10.1073/pnas.1606178113
发表时间：
2016-07-26
影响因子：
11.1
作者：
Senger, Moritz;Mebs, Stefan;Stripp, Sven Timo
通讯作者：
Stripp, Sven Timo
影响因子：
15
作者：
K. D. Swanson;Michael W. Ratzloff;David W. Mulder;Jacob H. Artz;Shourjo Ghose;A. Hoffman;S. White
通讯作者：
K. D. Swanson;Michael W. Ratzloff;David W. Mulder;Jacob H. Artz;Shourjo Ghose;A. Hoffman;S. White
影响因子：
15
作者：
Reijerse EJ;Pham CC;Pelmenschikov V;Gilbert-Wilson R;Adamska-Venkatesh A;Siebel JF;Gee LB;Yoda Y;Tamasaku K;Lubitz W;Rauchfuss TB;Cramer SP
通讯作者：
Cramer SP
影响因子：
62.1
作者：
Liu, Jing;Chakraborty, Saumen;Hosseinzadeh, Parisa;Yu, Yang;Tian, Shiliang;Petrik, Igor;Bhagi, Ambika;Lu, Yi
通讯作者：
Lu, Yi