Photo-crosslinking of clinically relevant kinases using H89-derived photo-affinity probes

The profiling of kinases using established proteomics techniques is hampered by their non-covalent mode-of-action. One way to overcome this caveat is the use of probes featuring photo-labelling groups that can be activated by UV irradiation to generate a reactive species that will establish a covalent bond to the enzyme. In this study we have used the well-known kinase inhibitor H89 as a lead for the development of probes for the affinity-based profiling of clinically relevant kinases. A labelling protocol was established for recombinant kinases and more complex protein mixtures using gel-based techniques. We also show that the probes act in a competitive manner with other kinase inhibitors.