Further adventures in shape space

It has been a long-held assumption in ligand-based virtual screening that the bioactive conformation of a molecule is privileged. The assumption is that superior performance in 3D searching (pharmacophores, shape similarity) should be obtained when using the bioactive conformation of a query molecule for searching for other active molecules. A parallel assumption has been that extensive sampling of the conformational space of database molecules is necessary to obtain optimal performance for 3D ligand-based screening. Both of these assumptions will be critically assessed for ligand-based virtual screening carried out in shape space.