title: Nitrite and nitric oxide as inhibitors of nitrogenase from soybean bacteroids.
abstract: Nitrite was able to strongly inhibit C(2)H(2) reduction by nitrogenase from soybean bacteroids, whereas H(2) evolution was unaffected under the same conditions. NO inhibited both C(2)H(2) reduction and H(2) evolution; during C(2)H(2) reduction, sensitivity of nitrogenase to NO was higher than to NO(2), and the K(i) values were, respectively, 0.056 and 0.52 mM. Production of NO resulting from a reduction of NO(2) by dithionite in nitrogenase incubations was observed. However, the characteristics of inhibitions and the low level of NO generated by nitrite reduction ruled out the suggestion concerning a direct role of NO to explain the inhibitory effect of NO(2) on nitrogenase.
authors.affiliation: Laboratoire de Biologie végétale, Faculté des Sciences et des Techniques, Parc Valrose, 06034 Nice Cedex, France.
authors.forename: J C
authors.initials: JC
authors.lastname: Trinchant
authors.forename: J
authors.initials: J
authors.lastname: Rigaud