Peptides as tools in drug discovery.

Drug discovery in the post-genomics era provides enormous opportunities as well as new challenges. The discovery of effective therapeutics will require choosing the right targets, building robust sensitive assays, executing an efficient screening program and judicious follow-up on promising active compounds. These processes require the development and adoption of new tools and techniques that will allow the rapid and efficient movement of interesting targets through a discovery program. This review will describe how peptide ligands targeted to protein functional sites can be used to validate a site on a candidate target protein, aid in a structure-based design program and format robust, sensitive high-throughput screens to identify compounds that modulate the function of the target protein. Combining these approaches in an integrated discovery program creates a new paradigm that allows for rapid, parallel flow of multiple targets from target choice through lead identification.