Reversible versus irreversible binding

Reversible versus irreversible binding

Ligand binding can be classified into two types: reversible - a chemical bond is formed which easily dissociates again. irreversible - a chemical bond is formed in which the product is thermodynamically much more stable than the reactants such the reverse reaction does not take place (normally: ‘covalent binding’).

Agonists, which activate the receptor, are always reversible ligands.

Irreversible ligands always block receptor action, and are usually referred to as non-competitive antagonists. Once an irreversible ligand has bound the receptor, the receptor will not be available for other ligands anymore.