Binding of Naphthylvinylpyridines to DNA

The suggestion that planar, heterocyclic bases might be inserted between the bases of DNA was first put forth by Michaelis (1947), several years before the double helical structure of DNA had been proposed. In 1961 the phenomenon of intercalation was clearly described and characterized in the classical work of Lerman (1961) with proflavine. Since then many papers have appeared in which intercalation has been invoked as a mode of DNA-ligand interaction for aromatic compounds and hetero-cyclic bases. However, even with the simple structure of proflavine there is still disagreement about the nature of the interaction — in particular, whether the inter-calated molecule is partially or completely intercalated, and the relative importance of the electrostatic, hydrophobic, and hydrogen bonding forces which may stabilize the complex (Blake and Peacocke, 1968; Gilbert and Claverie, 1968).