Distance geometry analysis of ligand binding to drug receptor sites.

The method known as 'distance geometry approach' for receptor mapping procedures is discussed. In this method a ligand binding to a certain receptor is considered as a collection of ligand points. Binding sites of the receptor are either 'empty' or 'filled' site points; a ligand point might bind to an empty site point; filled site points indicate that at that point no binding is possible. A binding mode of a ligand is a list of which ligand points coincide with which empty binding sites. The applicability of the method for QSAR studies is discussed; as examples are mentioned the dihydrofolate reductase, beta 1- and beta 2-receptors. Finally, some ideas on future developments in receptor mapping are discussed.