Purity: > 90% by SDS - PAGE Format: Liquid in 20mM Tris pH 7.5 . Calmodulin has been known to act as an intracellular calcium sensor protein. When the intracellular Ca2+ concentration increases, calmodulin can bind up to four Ca2+, changing its conformation and regulating cellular functions such as activation or inhibition of a large number of enzymes, ion channels, and receptors. Recombinant human Calmodulin was expressed in E.coli and purified by conventional chromatography techniques.