Analysis of enzyme-substrate interactions from square-wave protein-film voltammetry of complex electrochemical-catalytic mechanism associated with reversible regenerative reaction

Abstract

The surface catalytic EC′ mechanism is considered as one of the most relevant models to describe electrochemical behavior of many enzyme-substrate systems under voltammetric conditions. In this work, we elaborate theoretically a specific surface catalytic EC′ mechanism that features reversible regenerative reaction under conditions of square-wave voltammetry. The features of calculated voltammograms strongly depend on the parameters related to the thermodynamics and kinetics of regenerative chemical step involved in this mechanism. We present a series of simulated square-wave voltammograms that can be used to establish diagnostic criteria for recognizing surface EC′rev mechanism. In addition, we propose simple methodologies that can be explored to evaluate the kinetics and thermodynamics parameters relevant to chemical catalytic reaction. In a comprehensive study, we elaborate the effect of parameters of regenerative reaction to the features of phenomena known as “quasireversible maximum” and “split net peaks of square-wave voltammograms”. The results reported in this work can be of significance to many experimentalists working in the field of enzymatic voltammetry and drug-drug interactions.