Electrocatalysis of nitrite reductase from Alcaligenes faecalis strain 6 mediated by native redox partner

A protein‐mediated electrocatalytic reaction is described. A blue protein from Alcaligenes faecalis strain 6 (AfBP) was used as a redox mediator for a nitrite reductase (NIR) from the same organism. Two steps of a homogeneous chemical reaction (AfBP‐NIR and NIR‐substrate), following the direct electron transfer reaction of AfBP (E C′C′), were analyzed, and the bimolecular rate constant of 1.8 × 106 M−1·S−1 for the AfBP‐NIR reaction was calculated from electrocatalytic current in cyclic voltammetry. The kinetic relation of the first and the second homogeneous reaction was discussed.