Frontal analysis microchip capillary electrophoresis to study the binding of ligands to receptors derivatized on magnetic beads

Abstract

The model binding of the glycopeptide antibiotic teicoplanin (Teic) from Actinoplanes teichomyceticus, immobilized on magnetic microspheres, to D-Ala-D-Ala terminus peptides was assessed using microchip capillary electrophoresis (MCE) with continuous frontal analysis (FA). Teic is closely related to vancomycin (Van), historically, the drug of last resort used to treat many gram-positive bacterial infections. Glycopeptide antibiotics inhibit bacterial growth by binding to the D-Ala-D-Ala terminus on the cell wall of gram-positive bacteria via hydrogen bonds, thereby preventing the enzyme-mediated cross-linking of peptidoglycan and eventual cell death. In this work direct and competitive bead-based assays in a microfluidic chip are demonstrated. The binding constants obtained using the technique are comparable with values reported in the literature.