CALMODULIN-DEPENDENT PROTEIN KINASE II (290-309)

CaM Kinase II (290-309), Calmodulin Antagonist is a potent, synthetic peptide inhibitor of CaMKII (Ca²⁺/calmodulin-dependent protein kinase II), which was derived from the cDNA sequence of the rat brain 50-kDa alpha subunit. The use of this inhibitory peptide elucidated the calmodulin binding and inhibitory domains, as well as the initial autophosphorylation site (Thr286) of CaMKII with an IC₅₀ of 52 nM. This peptide product binds CaM (calmodulin) tightly and inhibits additional calmodulin-requiring enzymes, such as PDE (phosphodiesterase) and PP2B (calcineurin). Investigators used this product in STC-1 cells to study the regulation of L-type calcium channels and found the inhibitory peptide to block whole cell calcium currents. Additional research in T84 cells showed that this peptide reduced chloride current by approximately 70% without effect on the channels in parotid acinar cells.