• allosteric modulation
• bivalent ligands
• G-protein coupled receptors

This thesis is aimed at providing an overview about the relevant role played in drug design by the knowledge, at a molecular level, of ligand (drug)-receptor (biological terget) interactions as well as paths that ligands should follow to reach their binding site(s) within the receptor. This research led at developing a basic approach for rational design of ligands, which are endowed of particular mechanisms, that is bivalent ligands and allosteric modulators, of interaction with the receptor of interest.