| Autor: |
Lan, Deng, Hongxin, Wang, Christie H, Dapper, William E, Newton, Sergey, Shilov, Shunlin, Wang, Stephen P, Cramer, Zhao-Hui, Zhou |
| Rok vydání: |
2021 |
| Předmět: |
|
| Zdroj: |
Commun Chem |
| ISSN: |
2399-3669 |
| Popis: |
Protonation of FeMo-cofactor is important for the process of substrate hydrogenation. Its structure has been clarified as Δ-Mo*Fe(7)S(9)C(R-homocit*)(cys)(Hhis) for the efforts of nearly 30 years, while it remains controversial whether FeMo-cofactor is protonated or deprotonated with chelated ≡C–O(H) homocitrate. We have used protonated molybdenum(V) lactates 1 and its enantiomer as model compounds for R-homocitrate in FeMo-cofactor of nitrogenase. Vibrational circular dichroism (VCD) spectrum of 1 at 1051 cm(−1) is attributed to ≡C–O(H) vibration, and molybdenum(VI) R-lactate at 1086 cm(−1) is assigned as ≡C–O(α-alkoxy) vibration. These vibrations set up labels for the protonation state of coordinated α-hydroxycarboxylates. The characteristic VCD band of NMF-extracted FeMo-cofactor is assigned to ν(C–O(H)), which is based on the comparison of molybdenum(VI) R-homocitrate. Density Functional Theory calculations are in consistent with these assignments. To the best of our knowledge, this is the first time that protonated R-homocitrate in FeMo-cofactor is confirmed by VCD spectra. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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