Lyophilized. Lyophilized from 10 mM sodium phosphate buffer, 5% sucrose, pH 7.0. PROTECT FROM LIGHT. AVOID FREEZE/THAW CYCLES. Calmodulin (CaM) purified from porcine brain and labeled with rhodamine-NHS ester. CaM is a ubiquitous, calcium-binding protein that interacts with and regulates a wide variety of proteins, thus affecting different cellular functions and calcium-calmodulin-dependent signaling pathways. CaM mediates several biological processes, such as inflammation, metabolism, apoptosis, muscle contraction, intracellular movement, short-term and long-term memory, nerve growth, and the immune response. Useful for enzyme activation, CaM binding studies, and general assessment of CaM-dependent signaling pathways. Rhodamine/Protein Ratio: 0.5-1.0 as determined by absorbance. Specific activity: ≥ 35,000 U/mg protein. One unit is defined as the amount of calmodulin that will stimulate 0.01 unit of 3'5'-cyclic nucleotide phosphodiesterase to 50% of the maximum activity of the enzyme when saturated with CaM in the presence of 100 µM Ca²⁺ in a 3 ml reaction volume at 30°C, pH 7.5. Purity: >98% by SDS-PAGE.

Ref.: Billingsley, M.L., et al. 1985. Proc. Natl. Acad. Sci. USA 82, 7585.