Moment Analysis Theory for Kinetic Study of Intermolecular Interaction by Affinity Capillary Electrophoresis

Abstract

Abstract The moment analysis (MA) theory was introduced into the analysis of elution peak profiles measured by affinity capillary electrophoresis (ACE). New moment equations were developed, which were essential for analytically determining the association (ka) and dissociation (kd) rate constants of intermolecular interactions from the ACE data. The combination of the MA theory and ACE procedure leads to a method for the kinetic study of intermolecular interactions (MA-ACE). Because ACE has quite frequently been used for determining binding (association equilibrium) constants of intermolecular interactions, it must be important that ka and kd can also be determined from ACE elution peaks. An attempt was made to analyze ACE elution peaks in a published paper by the MA method to determine the rate constants. The values of ka and kd were analytically determined for the intermolecular interaction between three boronic acids and fructose. They were comparable with those determined by the other method based on the macroscopic approach for studying kinetics at equilibrium. It was demonstrated that the MA method was effective for extracting information about affinity kinetics of intermolecular interactions from elution peaks measured by ACE. This means that the MA method makes it possible to use ACE data previously published as a source for kinetic study of intermolecular interactions.