Cefatrizine is an inhibitor of eukaryotic elongation factor-2 kinase, a unique calcium/calmodulin-dependent protein kinase, is well known to regulate apoptosis, autophagy and ER stress in many types of human cancers.
Fluphenazine is a traditional antipsychotic compound that tightly binds the dopamine D2 receptor (Ki = 0.55 nM) and also reversibly inhibits calmodulin at micromolar concentrations. Fluphenazine-N-2-chloroethane is a derivative of fluphenazine that contains an alkylating chlorethylamine chain, which produces irreversible protein binding. It is a relatively selective, irreversible antagonist of D2 receptors both in vitro (IC50 = 100 nM) and in vivo, inactivating approximately 90% of D2 receptors in mice within 4 hours of treatment. Through this action, fluphenazine-B-2-chloroethane can be used to induce catalepsy in mice. It irreversibly inhibits calmodulin at higher doses (IC50 = 10 μM), which can sensitize cancer cells to TRAIL-induced apoptosis.
Calmodulin antagonist-1 (W-7) is a calmodulin (CaM) antagonist that effectively inhibits calmodulin-activated Ca 2+ -phosphodiesterase (PDE) with an IC 50 of 28 μM. This compound also competitively inhibits trypsin-treated Ca 2+ -PDE with respect to cyclic GMP, exhibiting an IC 50 of 375 μM and a K i value of 300 μM.