Nonequilibrium Capillary Electrophoresis of Equilibrium Mixtures, Mathematical Model

Abstract

We recently introduced a new electrophoretic method, nonequilibrium capillary electrophoresis of equilibrium mixtures (NECEEM). NECEEM provides a unique way of finding kinetic and equilibrium parameters of the formation of intermolecular complexes from a single electropherogram and allows for the use of weak affinity probes in protein quantitation. In this work, we study theoretical bases of NECEEM by developing a mathematical model for the new method. By solving a system of partial differential equations with diffusion in linear approximation, we found the analytical solution for concentrations of components involved in complex formation as functions of time from the beginning of separation and position in the capillary. The nonnumerical nature of the solution makes it a powerful tool in studying the theoretical foundations of the NECEEM method and modeling experimental results. We demonstrate the use of the model for finding binding parameters of complex formation by nonlinear regression of NECEEM electropherograms obtained experimentally.

Tau protein binds single‐stranded DNA sequence specifically – the proof obtained in vitro with non‐equilibrium capillary electrophoresis of equilibrium mixtures

“…The three KCE methods constitute a comprehensive toolset for measuring kinetic and equilibrium parameters of protein-DNA complexes [13][14][15][16]. Moreover, they facilitate a number of other applications ranging from quantitative analyses of proteins, DNA, and RNA [14] to selection of aptamers [17].…”

Moment Analysis Theory for Size Exclusion Capillary Electrochromatography with Chemical Reaction of Intermolecular Interaction

“…40,42 Some methods based on CE have also been developed for the kinetic study of intermolecular interactions, 44 e.g., affinity capillary electrophoresis, 45 exponential decay method, 46 and kinetic capillary electrophoresis (KCE). [47][48][49][50][51] In these methods, ka and kd are determined by matching electropherograms or exponential decay curves numerically calculated by changing the rate constants to those experimentally measured. Macroscopic approach for studying kinetics at equilibrium (MASKE) was also developed for measuring equilibrium and kinetic parameters in the state of chemical equilibrium.…”

Characterization of interactions between organotin compounds and human serum albumin by capillary electrophoresis coupled with inductively coupled plasma mass spectrometry

“…where A C , A AC , and A A are the peak areas of the complex, dissociating part of complex, and organotin compounds, while [P] 0 and [A] 0 are the known initial protein and organotin compound concentrations [28]. There are non-linear and linear regression methods for the data treatment.…”