Structure searching conformational flexibility

ACE = angiotensin converting enzyme BFGS optimization = Broyden-Fletcher-Goldfarb-Shanno optimization CFS search = conformationally flexible structure search CNS central nervous system CSD = Cambridge Structural Database PDB = Brookhaven Protein Data Bank SBDD = structure-based drug design. 

Comparative Molecular Field Analysis (CoMFA) Conformational Flexibility in 3D Structure Searching Conformational Search Medium-sized Molecules Conformational Search Proteins Genetic and Evolutionary Algorithms Molecular Docking and Structure-based Design Shape Analysis Structural Similarity Measures for Database Searching Structure and Substructure Searching Structure Databases. 

In order to make the representation of structures in the computer prone to an efficient handling and searching, a variety of problems have to be solved unique and unambiguous representation, analysis of rings or shape, definition of structural similarity or diversity, handling of 3D structures, and conformational flexibility. 

In all of the 3D search methods the conformational flexibility creates considerable difficulties. Large databases of multiple conformations for each structure have been developed which make the solution of this problem possible. 

Bcl-2 is one of the many factors that control apoptosis, and overexpression of Bcl-2 has been observed in many different cancers. A homology model of Bcl-2 was derived from the NMR 3D structure of the Bcl-XL complex with a Bak BH3 peptide. This model served to search the NCI 3D database of 206,876 organic compounds for potential Bcl-2 inhibitors, which bind to the Bak BH3 binding site of Bcl-2. Full conformational flexibility of the ligands was taken into account in the program DOCK. Thirty-five potential inhibitors were tested, and seven of them had IC50 values from 1.6 to W.OpM. One of... 

ChemCore module to three-dimensionalize 2D structures, interfaces to reformat MACCS, SMILES, or DARC-2D databases, ChemDBS-1 module to build 3D databases, and ChemDBS-3D module to search 3D databases. Database searching accounts for conformational flexibility while storing only one conformation. Chapman 8c Hall s 3D Dictionary of Drugs (12,000 medicinally interesting compounds), 3D Dictionary of Natural Products (50,000 antibiotics, alkaloids, and terpenoids), and 3D Dictionary of Fine Chemicals (105,000 organics). 

Clark, D.E., Willett, P. and Kenny, P. (1992). Pharmacophoric Pattern Matching in Files of Three-Dimensional Chemical Structures Use of Smoothed-Bounded Distance Matrices for the Representation and Searching of Conformationally-Flexible Molecules. J.MoLGraphics, 10,194-204. 

---