Assessment of the binding characteristics of three antagonists toward CysLTR1 by affinity chromatography

It is crucial to determine equilibrium and kinetics of drug-receptor interactions for understanding thoroughly drug mechanism and drug efficacy. In this work, three antagonist drugs toward cysteinyl leukotriene receptor 1 (CysLTR1) were exemplified to measure the binding parameters by multiple affinity chromatographic approaches like frontal chromatography, injection amount-dependent method and nonlinear chromatography. The association equilibrium constants were measured as montelukast < zafirlukast < pranlukast and the dissociation rate constants were in the rank of montelukast > zafirlukast > pranlukast, which were correlated to the inhibition potencies of montelukast < zafirlukast < pranlukast to CysLTR1. Additionally, thermodynamic analysis in combination with molecular docking indicated that the three antagonists were spontaneously bound to CysLTR1 and their bindings were mainly driven by hydrogen bonds and van der Waals forces. Our work demonstrated that affinity chromatography can be utilized to evaluate the binding characteristics of ligand-receptor based on their retention behaviors, aiding the selection of the best ligands for further studies to become a drug molecule.