Mediated Electrochemistry of Nitrate Reductase from <i>Arabidopsis thaliana</i>
- Publication date
- Publisher
Abstract
Herein we report the mediated electrocatalytic
voltammetry of the
plant molybdoenzyme nitrate reductase (NR) from <i>Arabidopsis
thaliana</i> using the established truncated molybdenum-heme
fragment at a glassy carbon (GC) electrode. Methyl viologen (MV),
benzyl viologen (BV), and anthraquinone-2-sulfonic acid (AQ) are employed
as effective artificial electron transfer partners for NR, differing
in redox potential over a range of about 220 mV and delivering different
reductive driving forces to the enzyme. Nitrate is reduced at the
Mo active site of NR, yielding the oxidized form of the enzyme, which
is reactivated by the electro-reduced form of the mediator. Digital
simulation was performed using a single set of enzyme dependent parameters
for all catalytic voltammetry obtained under different sweep rates
and various substrate or mediator concentrations. The kinetic constants
from digital simulation provide new insight into the kinetics of the
NR catalytic mechanism