Related Experiment Video
Updated: Aug 8, 2026
![Protein Film Infrared Electrochemistry Demonstrated for Study of H2 Oxidation by a [NiFe] Hydrogenase](/_next/image?url=https%3A%2F%2Fcloudfront.jove.com%2FCDNSource%2Fteasers%2F55858.jpg&w=3840&q=50)
Protein Film Infrared Electrochemistry Demonstrated for Study of H2 Oxidation by a [NiFe] Hydrogenase
Published on: December 4, 2017
The photoreduction of nitrogenase
Druzhinin SYu1, L A Syrtsova, A M Uzenskaja
1Institute of Chemical Physics, Russian Academy of Sciences, Moscow region.
Abstract:
The photoreduction, without reductant dithionite, of N2 to NH3 or acetylene to ethylene catalysed by nitrogenase in the presence of Mg2+. ATP, eosin and NADH in the light has been established. There is an optimum NADH concentration for each particular eosin concentration. When the ratio of the iron protein component of nitrogenase from Azotobacter vinelandii (Av2)/the molybdenum-iron protein component of nitrogenase from A. vinelandii (Av1) is equal to 3 for 4 x 10(-5) M eosin the optimum NADH concentration is 5 x 10(-4) M. The rate of photoreduction (per one electron) of acetylene or N2 under identical conditions was shown to be similar. The photoreductant-dependent ATPase activity, in the presence of a given photochemical system in the light, was revealed. Eosin is shown to be the inhibitor of the coupling site. Concentrations of 8 x 10(-6) -1 x 10(-4) M eosin do not inhibit the ATPase activity. The inhibition of substrate-reduction activity depends on the ratio of the nitrogenase components. Under conditions where the Av2/Av1 ratio is equal to 1 the rate of photochemical reduction is higher than in the presence of dithionite: the total electron flux through nitrogenase being increased 2.2-fold. We suggest that in this case the nitrogenase complex (1:1) works without dissociation.
More Related Videos
Related Concept Videos
The Z-Scheme of Electron Transport in Photosynthesis
Nitriles to Amines: LiAlH4 Reduction
As shown below, the mechanism involves three steps. Firstly, the hydride ion acting as a nucleophile attacks the nitrile carbon to form an anion. In the second step, a second equivalent of the hydride ion attacks the anion to...
Electrophilic Aromatic Substitution: Nitration of Benzene
Preparation of Amines: Reduction of Oximes and Nitro Compounds
Though catalytic hydrogenation can reduce nitrobenzenes, the reduction is nonselective in the presence of other functional groups. For instance, if nitrobenzene contains an aldehyde group,...
Anoxygenic Photosynthesis
Inorganic Nitrogen Assimilation

