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. 1991 Jul 15;277(Pt 2):465–468. doi: 10.1042/bj2770465

Hydrazine is a product of dinitrogen reduction by the vanadium-nitrogenase from Azotobacter chroococcum.

M J Dilworth 1, R R Eady 1
PMCID: PMC1151257  PMID: 1859374

Abstract

During the enzymic reduction of N2 to NH3 by Mo-nitrogenase, free hydrazine (N2H4) is not detectable, but an enzyme-bound intermediate can be made to yield N2H4 by quenching the enzyme during turnover [Thorneley, Eady & Lowe (1978) Nature (London) 272, 557-558]. In contrast, we show here that the V-nitrogenase of Azotobacter chroococcum produces a small but significant amount of free N2H4 (up to 0.5% of the electron flux resulting in N2 reduction) as a product of the reduction of N2. The amount of N2H4 formed increased 15-fold on increasing the assay temperature from 20 degrees C to 40 degrees C. Activity cross-reactions between nitrogenase components of Mo- and V-nitrogenases showed that the formation of free N2H4 was associated with the VFe protein. These data provide the first direct evidence for an enzyme intermediate at the four-electron-reduced level during the reduction of N2 by V-nitrogenase.

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Selected References

These references are in PubMed. This may not be the complete list of references from this article.

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