Electrochemical reduction of cytochromes P450 using electrodes containing immobilized substrates

A new approach for the electrochemical reduction of cytochromes P450 (P450, CYPs) with electrodes chemically modified with CYP appropriate substrates (“reverse” electrodes) has been proposed. The method is based on the analysis of cyclic voltammograms, square wave voltammograms, amperograms and determination of such electrochemical characteristics as catalytic current and redox potential. The differences of maximal current and potentials in square wave voltammograms and catalytic current in amperometric measurements are more sensitive and reliable. The planar mode of screen-printed electrodes permits to use 20–60 μl of electrolyte volume. We have investigated P450 2B4-benzphetamine or P450scc-cholesterol enzyme-substrate pairs. Electrochemical parameters of electrodes with nonspecific P450 substrate were differed from the electrodes with appropriate substrates.