Novel recognition mechanisms in biological adhesion

Molecular recognition is generally thought of in terms of bond formation between unique sites on host and complementary guest molecules, but recent studies have revealed new complexities in biological recognition at cell. Adhesion between cell surfaces similarly involves specific interactions between analogous ligands and receptors. Recent force measurements, however, suggest that cell adhesion proteins may bind via multiple interaction sites that can form in a sequential manner. Other studies further show that in some instances, the principal recognition event may not be receptor–ligand docking, but the assembly of a complex pattern of many receptors and ligands.