ISOSTAR - A LIBRARY OF INFORMATION ABOUT NONBONDED INTERACTIONS

Crystallographic and theoretical tab initio) data on intermolecular no nbonded interactions have been gathered together in a computerised lib rary ('IsoStar'). The library contains information about the nonbonded contacts formed by some 250 chemical groupings. The data can be displ ayed visually-and used to aid protein-ligand docking or the identifica tion of bioisosteric 'replacements. Data from the library show that th ere is great variability in the geometrical preferences of different t ypes of hydrogen bonds, although in general there is a tendency for H- bonds to form along lone-pair directions. The H-bond acceptor abilitie s of oxygen and sulphur atoms are highly dependent on intramolecular e nvironments. The nonbonded contacts formed by many hydrophobic groups show surprisingly strong directional preferences. Many unusual nonbond ed interactions are to be found in the library-and are of potential va lue for designing novel biologically active molecules.