Camk2n1, also known as Calcium/calmodulin-dependent protein kinase II inhibitor 1, belongs to the CAMK2N family. This protein interacts with CAMK2B; the presence of Ca2+/calmodulin increases the interaction but is not essential. It also interacts with CAMK2A; this interaction requires CAMK2A activation by Ca2+. Camk2n1 is potent and specific inhibitor of CaM-kinase II (CAMK2). Recombinant mouse Camk2n1 protein, fused to His-tag at N-terminus, was expressed in E.coli and purified by using conventional chromatography techniques.