Abstract: Methods are provided for modulating Ligand-Receptor interactions by binding of molecules at two epitopes of a receptor, where the epitopes are in relatively close special relationship. By providing for inhibition of changes in conformation of the receptor, where the inhibition is due to steric interactions or molecular bridging between the two epitopic sites, Ligand-Receptor interactions may be modulated. The modulation of Ligand-Receptor interactions has application to diagnostic assays, modulation of cellular activity, and modulation of the physiological activity of macromolecular compounds.