What is Ligand?
[[Image:Myoglobin and heme.png|thumb|230px|right|[[Myoglobin]] (blue) with its ligand [[heme]] (orange) bound.]] A '''ligand''' is a [[biochemical]] substance. Its function is to bind to a [[biological]] [[molecule]], and make the molecule perform a [[Function (biology)|function]]. Ligand binding alters the shape of the receptor [[protein]]. This changes the protein's behaviour. In a narrower sense, it is a [[Signal transduction|signal triggering]] molecule, binding to a [[site]] on a target [[protein]]. The binding occurs by [[intermolecular force]]s, such as [[ionic bond]]s, [[hydrogen bond]]s and [[van der Waals]] forces. The [[docking]] (association) is usually reversible (dissociation). Ligands include [[Substrate (biochemistry)|substrate]]s, [[inhibitor]]s, [[activator]]s, and [[neurotransmitter]]s. The tendency or strength of binding is called [[#Receptor/ligand binding affinity|affinity]]. == Related pages == *[[Signal transduction]] *[[Cytokine]] *[[Agonist]] *[[Receptor antagonist]] == References == [[Category:Biochemistry]] [[Category:Molecular biology]]