Irreversible Inactivation of Initial Form of Water-Soluble Redox Proteins-Theoretical Study in Square-Wave Voltammetry

Inactivation of water-soluble redox proteins and enzymes is often encountered in many biological systems under physiological conditions. In electrochemical experiments, if the initial redox form of a given water-soluble redox protein is engaged at the same time in an electrochemical transformation on the working electrode and in an irreversible chemical reaction, then the voltammetric outputs might show quite specific behavior due to the simultaneous interplay of electron transfer step and the chemical reaction. In this work, we present for the first time theoretical results of such a model applicable to the electrochemistry of hydrophilic redox proteins under conditions of square-wave voltammetry. We present the readers a large tabular overview of a series of voltammetric patterns of this electrode mechanism calculated at different rates of electron transfer step and different kinetics of chemical step. Moreover, in the work we give hints to apply suitable methodology to recognize this mechanism under conditions of square-wave voltammetry, while giving directions on how to assess the kinetics of both steps involved in this mechanism. The results elaborated in this work should be of help to experimentalists working in enzymatic voltammetry.