Kinetics of substrate inhibition of periplasmic nitrate reductase - Archive ouverte HAL Accéder directement au contenu
Article Dans Une Revue Biochimica biophysica acta (BBA) - Bioenergetics Année : 2014

Kinetics of substrate inhibition of periplasmic nitrate reductase

Résumé

Periplasmic nitrate reductase catalyzes the reduction of nitrate into nitrite using a mononuclear molybdenum cofactor that has nearly the same structure in all enzymes of the DMSO reductase family. In previous electrochemical investigations, we found that the enzyme exists in several inactive states, some of which may have been previously isolated and mistaken for catalytic intermediates. In particular, the enzyme slowly and reversibly inactivates when exposed to high concentrations of nitrate. Here, we study the kinetics of substrate inhibition and its dependence on electrode potential and substrate concentration to learn about the properties of the active and inactive forms of the enzyme. We conclude that the substrate-inhibited enzyme never significantly accumulates in the EPR-active Mo(+ V) state. This conclusion is relevant to spectroscopic investigations where attempts are made to trap a Mo(+ V) catalytic intermediate using high concentrations of nitrate.

Dates et versions

hal-01494456 , version 1 (23-03-2017)

Identifiants

Citer

Julien G.J. Jacques, Bénédicte Burlat, Pascal Arnoux, Monique Sabaty, Bruno Guigliarelli, et al.. Kinetics of substrate inhibition of periplasmic nitrate reductase. Biochimica biophysica acta (BBA) - Bioenergetics, 2014, BBA Bioenergetics, 1837 (10), pp.1801 - 1809. ⟨10.1016/j.bbabio.2014.05.357⟩. ⟨hal-01494456⟩
78 Consultations
0 Téléchargements

Altmetric

Partager

Gmail Facebook X LinkedIn More