Exploring Electron/Proton Transfer and Conformational Changes in the Nitrogenase MoFe Protein and FeMo-cofactor Through Cryoreduction/EPR Measurements.

ABSTRACT: We combine cryoreduction/annealing/EPR measurements of nitrogenase MoFe protein with results of earlier investigations to provide a detailed view of the electron/proton transfer events and conformational changes that occur during early stages of [e^-/H⁺] accumulation by the MoFe protein. This includes reduction of (i) the non-catalytic state of the iron-molybdenum cofactor (FeMo-co) active site that is generated by chemical oxidation of the resting-state cofactor (S = 3/2)) within resting MoFe (E₀), and (ii) the catalytic state that has accumulated n =1 [e^-/H⁺] above the resting-state level, denoted E₁(1H) (S ≥ 1) in the Lowe-Thorneley kinetic scheme. FeMo-co does not undergo a major change

SUBMITTER: Davydov R 

PROVIDER: S-EPMC5074565 | biostudies-literature | 2016 Oct

REPOSITORIES: biostudies-literature