Assignment of protonated R-homocitrate in extracted FeMo-cofactor of nitrogenase via vibrational circular dichroism spectroscopies.

ABSTRACT: Protonation of FeMo-cofactor is important for the process of substrate hydrogenation. Its structure has been clarified as Δ-Mo*Fe₇S₉C(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 coo

SUBMITTER: Deng L 

PROVIDER: S-EPMC8323615 | biostudies-literature | 2020

REPOSITORIES: biostudies-literature