Calmodulin is a bioactive protein isolated from bovine testes with a molecular weight of 16,7 kDa. The material is derived from cattle born and raised in Sweden, a country where BSE is non-existing. Calmodulin is a calcium-binding protein expressed in many eukaryotic cells. By binding to and regulating various protein targets, it affects cellular processes such as metabolism, nerve growth, apoptosis, inflammation, muscle contraction and memory. Many proteins use Calmodulin as a calcium sensor and signal transducer, as the proteins themselves are not able to bind calcium. The molecule can bind a maximum of four calcium ions and by undergoing post-translational modifications such as acetylation, phosphorylation, proteolytic cleavage and methylation, its functions can potentially be altered. Calmodulin is supplied as a lyophilized white powder or flocculate from 50 mM NH4HCO3 with 10 μM CaCl2. No preservatives are added. The protein content is analyzed by amino acid assay and is never less than 80 % of weighed substance. The material has been subjected to an acid treatment for minimum 30 min. The protein is derived from a single batch and is homogenous.