A ligand is a molecule or ion that binds to a central metal atom to form a coordination complex in coordination chemistry. In biochemistry and pharmacology, a ligand is a substance that forms a complex with a biomolecule to serve a biological purpose). Here are some key points about ligands:
- Ligands can be anions, cations, and neutral molecules.
- They act as Lewis bases (donate electron pairs), and central metal atoms are viewed as Lewis acids (electron pair acceptors) .
- The nature of bonding from metal to ligand varies from covalent bond to ionic bond.
- Ligands can be intracellular or extracellular.
- In general, the interpretation of ligand is contextual with regards to what sort of binding has been observed).
- Ligands include substrates, inhibitors, activators, signaling lipids, and neurotransmitters).
- The rate of binding is called affinity, and this measurement typifies a tendency or strength of the effect).
- Ligands of proteins can be characterized also by the number of protein chains they bind).
Examples of ligands include F–, Cl–, Br–, I–, S2–, CN–, NCS–, OH–, NH2–, NH3, H2O, NO, CO, and many others. Peptide (protein) ligands make up the largest and most diverse class of water-soluble ligands.
