Structural biology in drug development.

Structural biologists focus on the structure of biomolecules. Several techniques are available to study the structure adopted by a biomolecule and unravel how this structure is related to its constitution and function. For their biological role in a functioning cell or organism, biomolecules interact with each other and/or rather small molecules in their environment. Drugs can exploit interaction with biomolecules to manipulate their biological function to obtain a therapeutic effect. Structure determination of biomolecules that (could) serve as therapeutic target is an important starting point in rational drug design. Once the structure of a biological target is known, a potential binding site for drugs and possible interactions at this site have to be identified. In the stage of drug design this information is a valuable input for modeling experiments. They can virtually scan libraries of compounds by docking them into the binding site. This strategy ranks potential ligands that can be chemically modified to optimize their interaction at the binding site ('lead optimization') in order to improve affinity and selectivity for the biomolecular target. Modeling can also be used to virtually 'build' new molecules starting from possible interactions and shape of the target binding site ('de novo design'). Structural biology can contribute in different stages of drug development to direct the process or optimize existing compounds.