[Screening of protein kinase inhibitors]

To screen the compounds that inhibit protein kinases, we used an assay system in which activities of protein kinase A, protein kinase C, src family protein tyrosine kinases and eukaryotic elongation factor 2 kinase were simultaneously detected on a single gel for the cytoplasmic protein kinases. For the receptor type protein kinases, EGFR and Flt-1 tyrosine kinases were examined. Here, we briefly described some of the protein kinase inhibitors that have been approved or are under clinical development, and present some novel inhibitors that were found in our screening system.