Abstract
The protocols in this unit describe efficient and cost-effective approaches to determine the interaction of small-molecule inhibitors with native kinases, and also analyze the interactions between kinases and their binding partners in a cellular setting. The combined attributes of activity-based probes and western blotting procedures provide for quantitative measurement of inhibitor efficacy, isoform selectivity, and post-translational modifications. We further demonstrate the ability to identify protein-protein interactions between a probe-labeled protein and its noncovalent binding partners.