NRGN, also known as Neurogranin, is a calmodulin-binding protein expressed exclusively in the brain, particularly in dendritic spines, and participating in the protein kinase C signaling pathway. This protein is the main postsynaptic protein regulating the availability of calmodulin, binding to it in the absence of calcium. Phosphorylation by protein kinase C lowers its binding ability. Recombinant human NRGN protein, fused to His-tag at N-terminus, was expressed in E.coli and purified by using conventional chromatography