Department of Inorganic Spectroscopy, Max Planck Institute for Chemical Energy Conversion, Stiftstrasse 34-36, 45470, Mülheim an der, Ruhr, Germany.
Angew Chem Int Ed Engl. 2022 Oct 10;61(41):e202209190. doi: 10.1002/anie.202209190. Epub 2022 Sep 7.
The biological process of dinitrogen reduction to ammonium occurs at the cofactors of nitrogenases, the only enzymes that catalyze this challenging chemical reaction. Three types of nitrogenases have been described, named according to the heterometal in their cofactor: molybdenum, vanadium or iron nitrogenases. Spectroscopic and structural characterization allowed the unambiguous identification of the cofactors of molybdenum and vanadium nitrogenases and revealed a central μ -carbide in both of them. Although genetic studies suggested that the cofactor of the iron nitrogenase contains a similar Fe C core, this has not been experimentally demonstrated. Here we report Valence-to-Core X-ray Emission Spectroscopy providing experimental evidence that this cofactor contains a carbide, thereby making the Fe C core a feature of all nitrogenase cofactors.
氮气还原为铵的生物过程发生在氮酶的辅因子中，氮酶是唯一能催化这种具有挑战性的化学反应的酶。已经描述了三种类型的氮酶，根据其辅因子中的杂金属命名为钼、钒或铁氮酶。光谱和结构特征分析明确鉴定了钼和钒氮酶的辅因子，并在两者中都揭示了一个中心μ-碳化钼。尽管遗传研究表明铁氮酶的辅因子含有类似的 Fe-C 核，但这尚未在实验中得到证实。在这里，我们报告了价态到核心 X 射线发射光谱，提供了实验证据，表明该辅因子含有碳化钼，从而使 Fe-C 核成为所有氮酶辅因子的特征。
