Ligands are small or large molecules that can bind to transmembrane receptor or intracellular protein targets such as enzymes and alter the state of the target molecule. These ligands can be a variety of molecules including small molecule chemicals, proteins such as growth factors and cytokines, as well as antibodies. In drug discovery and development, ligands are often used as probes to determine the ligand's mechanism of action (MOA), understand the target's function, or identify and screen potential drug targets.
Ligands can be classified as agonists, partial agonists, super agonists, allosteric modulators, or antagonists, depending on whether they activate, change, or inhibit the target protein they bind. When activating ligands bind to a target, the structure is altered. The binding may lead to the dimerization of a receptor and/or initiation of a cascade of cellular signal transduction events ultimately leading to a unique cellular response or phenotype. Many such cellular responses are vital for the proliferation, migration, survival, and differentiation of cells within all multicellular organisms. In contrast, inhibitor ligands typically block signaling. Inhibitors of intracellular proteins like enzymes fall under the reversible or irreversible types. While both types bind to the target protein, the reversible inhibitors dissociate from the target under certain conditions, whereas irreversible inhibitors do not. Overall, inhibitors play a significant role in drug discovery and are used to analyze cellular pathways and treat various disorders.
Choose from a variety of small molecules, peptides, and recombinant proteins as control ligands and inhibitors as well as antibodies and antibiotics that support Eurofins DiscoverX® cell-based assays for developing your target-based therapeutics development.