The present invention provides small molecules having high affinity to the ATP binding site of protein kinases, which are conjugated to apeptide or peptidomimetic moiety which mimics the substrate of PKB. The chimeric compounds according to the present invention preferably serve as PKB inhibitors with improved activity and selectivity. Novel ATP mimetic compounds, particularly isoquinoline derivatives, conjugated with peptides or peptidomimetics are useful as inhibitors of protein kinases for experimental, medical, and drug design purposes. Furthermore, pharmaceutical compositions comprising these protein kinase inhibitors, and methods of using such compositions for treatment and diagnosis of cancers, diabetes, cardiovascular pathologies, hemorrhagic shock, obesity, inflammatory diseases, diseases of the central nervous system, and autoimmune disease, are disclosed.