Bisindolylmaleimide II (BIM II) is a general inhibitor of all protein kinase C (PKC) subtypes with structural similarity to the nonspecific PKC inhibitor staurosporine. At 10 μM, BIM II inhibits 98% of PKCα kinase activity. Additionally, it inhibits PDK1 (IC50 = 14 μM), an important kinase in the insulin signaling pathway, and PKA (IC50 = 2.94 μM). Studies of structure-activity relationships of BIM II in complex with PDK1 and PKA kinase binding domains has led to useful insights into kinase/ligand binding for the rational design of inhibitors as potential therapeutic agents.