| アイテムタイプ |
学術雑誌論文 / Journal Article(1) |
| 公開日 |
2024-09-02 |
| タイトル |
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タイトル |
New insights into the oxidation process from neutron and X-ray crystal structures of an O2-sensitive [NiFe]-hydrogenase |
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言語 |
en |
| 言語 |
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言語 |
eng |
| 資源タイプ |
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資源タイプ識別子 |
http://purl.org/coar/resource_type/c_6501 |
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資源タイプ |
journal article |
| 著者 |
廣本 武史
西川 幸志
井上 誠也
緒方 英明
堀 優太
日下 勝弘
平野 優
栗原 和男
重田 育照
玉田 太郎
樋口 芳樹
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| 抄録 |
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内容記述タイプ |
Abstract |
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内容記述 |
[NiFe]-hydrogenase from Desulfovibrio vulgaris Miyazaki F is an O2-sensitive enzyme that is inactivated in the presence of O2 but the oxidized enzyme can recover its catalytic activity by reacting with H2 under anaerobic conditions. Here, we report the first neutron structure of [NiFe]-hydrogenase in its oxidized state, determined at a resolution of 2.20 A. This resolution allowed us to reinvestigate the structure of the oxidized active site and to observe the positions of protons in several short hydrogen bonds. X-ray anomalous scattering data revealed that a part of the Ni ion is dissociated from the active site Ni?Fe complex and forms a new square-planar Ni complex, accompanied by rearrangement of the coordinated thiolate ligands. One of the thiolate Sγ atoms is oxidized to a sulfenate anion but remains attached to the Ni ion, which was evaluated by quantum chemical calculations. These results suggest that the square-planar complex can be generated by the attack of reactive oxygen species derived from O2, as distinct from one-electron oxidation leading to a conventional oxidized form of the Ni?Fe complex. Another major finding of this neutron structure analysis is that the Cys17S thiolate Sγ atom coordinating to the proximal Fe?S cluster forms an unusual hydrogen bond with the main-chain amide N atom of Gly19S with a distance of 3.25 A, where the amide proton appears to be delocalized between the donor and acceptor atoms. This observation provides insight into the contribution of the coordinated thiolate ligands to the redox reaction of the Fe?S cluster. |
| 書誌情報 |
Chemical Science
巻 14,
号 35,
p. 9606-9315,
発行日 2023-08
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| 出版者 |
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出版者 |
Royal Society of Chemistry |
| ISSN |
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収録物識別子タイプ |
ISSN |
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収録物識別子 |
2041-6520 |
| DOI |
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識別子タイプ |
DOI |
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関連識別子 |
10.1039/D3SC02156D |
