This is a lyophilized powder enzyme preparation with a specific activity of 15-30 units per mg protein, assayed in the presence of 0.03 mM Ca²⁺ and a saturating level (10 units per ml) of calmodulin (product P2277). It is a specialty biochemical reagent used in research applications involving calcium and calmodulin-dependent enzymatic reactions, such as signal transduction studies, protein phosphorylation assays, and investigations into cellular regulatory mechanisms. This niche catalyst enables precise analysis of enzyme kinetics and molecular interactions in vitro.