Multivalent Effects On Interactions Between The Ligand And Cell-Surface Receptors Probed By A Binding Force Spectroscopy

Monovalent and multivalent binding and unbinding interactions between peptide-ligands and integrin-receptors on living cell membrane were measured and quantified using an atomic force microscopy (AFM). Initially, we performed single-molecule force spectroscopy measurements with peptide-functionalized AFM probes, targeting specific integrin receptors, and identified and quantified the binding strength as well as receptors’ distribution on the cell membrane. Next, bivalent, trivalent, and multivalent binding interactions were examined and compared by varying the retracing and approaching speed of the AFM probes. Here, we discuss multivalent effects on the binding sensitivity, selectivity, and strength and their dependence on parameters including receptor concentrations of non-cancerous and cancerous cell-lines. This research was supported by the NIGMS/NIH R15GM122063 and 1P20GM109024.