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Updated: Aug 11, 2026

Pull-down of Calmodulin-binding Proteins
Published on: January 23, 2012
Effect of phosphorylation of calmodulin on calcium binding affinity as estimated by terbium fluorescence
T Aiuchi1, T Hagiwara, K Omata
1Laboratory of Biological Chemistry, School of Pharmaceutical Sciences, Showa University, Tokyo, Japan.
Abstract:
The effect of phosphorylation of calmodulin by casein kinase 2 on the calcium binding of the former was studied by measurement of terbium fluorescence. The binding of Tb3+ to calmodulin was followed by an increase in Tb3+ fluorescence at 545 nm. The terbium fluorescence of phosphorylated calmodulin increased at a lower concentration of Tb3+ than that of non-phosphorylated calmodulin, indicating that Tb3+ binding affinity of calmodulin was increased by phosphorylation. Our results suggest that the interaction between calcium and binding domain becomes stronger by phosphorylation.
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