UC San Diego

IκB kinase (IKK) is the essential kinase in the activation pathway of NF-κB, a family of transcription factors active in both innate and adaptive immunity. IKK has two catalytic subunits, IKK1 and IKK2, and one scaffolding subunit NEMO. As aberrant activation of NF-κB is a factor in many diseases including cancer and inflammatory disorders, research has been directed toward developing inhibitors to its activation. Most developed inhibitors target IKK2 and work as ATP competitors. However, ATP competitive inhibitors are often too nonspecific and have too many adverse side effects to be developed as effective drug treatments. I tested and characterized the function of small molecule allosteric inhibitors identified by our lab named #65.5, #65.5.2, and #65.5.3. Allosteric inhibitors of IKK2 are expected to result in greater specificity with fewer adverse side effects. I used cell-based assays, kinase experiments, HDXMS, and MS-MS to confirm that our inhibitors prevented NF-κB activation, worked as allosteric inhibitors, and bound to the pocket predicted by virtual screening. Based on analysis of the collected data, we developed a model for how our inhibitors work to prevent IKK2 activation.