Chemical approaches toward the design of selective and nonselective protein kinase inhibitors

BIOL 5

Nathanael Gray, Nathanael_Gray@dfci.harvard.edu, Dana Farber Cancer Institute, Harvard Medical School, Seeley G. Mudd building, 628A, 250 Longwood Ave., Boston, MA 02115
The vast majority of kinase inhibitors developed to date target the ATP binding site of the kinase in its “active” conformation where the activation loop is phosphorylated (Type I). Recently, crystal structures of inhibitors such as imatinib (STI571), BIRB796 and sorafenib (BAY43-9006) have revealed a new binding mode that exploits an additional binding site immediately adjacent to a region occupied by ATP (Type II). This pocket is made accessible by an activation loop rearrangement that is characteristic of kinases that are in an “inactive” conformation (Type II). Here, we present a structural analysis of binding modes of known Type II inhibitors and demonstrate that they conform to a pharmacophore model that is currently being used to design a new generation of kinase inhibitors. We also will discuss the discovery of a new class of non-ATP competitive Bcr-Abl kinase inhibitors.