Calmodulin-Dependent Protein Kinase II (290-309) is a potent CaMK antagonist with an IC₅₀ of 52 nM for inhibition of Ca2+/calmodulin-dependent protein kinase II. IC50 & Target: IC50: 52 nM (calmodulin-dependent protein kinase II)^[1] In Vitro: Peptide 290 to 309 is found to be a potent calmodulin antagonist with an IC₅₀ of 52 nM for inhibition of Ca2+/calmodulin-dependent protein kinase. Neither truncation from the amino terminus (peptide 296-309) nor extension in the carboxyl-terminal direction (peptide 294-319) markedly affects calmodulin binding, whereas shortening the peptide from the carboxyl terminus (peptide 290-302) or from both ends (peptide 295-304) results in the elimination of this activity^[1].