BioLiganden

BioLiganden are molecules that bind to biological targets, including proteins, nucleic acids, membranes, or metal ions, and participate in signaling, regulation, or metabolism. The term encompasses endogenous ligands produced by organisms as well as exogenous ligands such as drugs, probes, and toxins. They can act through reversible affinity or, less commonly, covalent interactions, and they are characterized by the complementarity of shape, charge, and hydrophobic/hydrophilic properties.

Biological ligands fall into several categories by origin and target. Endogenous ligands include neurotransmitters, hormones, metabolites, and nucleotides that bind receptors, enzymes, or transport proteins. Larger biomolecules such as peptides and proteins can serve as ligands for receptors or regulatory sites. In bioinorganic contexts, metal ions and metal-containing complexes act as ligands that modulate enzyme activity or structural metal centers, often via coordination chemistry.

Binding of BioLiganden to their targets can elicit physiological responses, inhibit catalysis, or stabilize specific conformations. Specificity arises from pocket geometry, noncovalent interactions, and, when applicable, allosteric effects that alter activity at distant sites.

Applications of BioLiganden include drug discovery and pharmacology, where a therapeutic agent functions as a ligand to modify a biological process; research tools and diagnostics that employ affinity ligands for labeling or isolation; and biosensors that detect biological molecules through selective binding. Challenges include achieving selectivity, bioavailability, and stability in complex biological environments.

Computational approaches and experimental data resources catalog BioLiganden, their targets, and binding modes, supporting structure-based design and comparative analyses across systems.