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Updated: Jun 14, 2026

Pull-down of Calmodulin-binding Proteins
Published on: January 23, 2012
Interactions of calmodulin with the multiple binding sites of Cav1.2 Ca2+ channels
Hadhimulya Asmara1, Etsuko Minobe, Zahangir A Saud
1Department of Physiology, Graduate School of Medical and Dental Sciences, Kagoshima University, Japan.
Abstract:
Although calmodulin binding to various sites of the Cav1.2 Ca(2+) channel has been reported, the mechanism of the interaction is not fully understood. In this study we examined calmodulin binding to fragment channel peptides using a semi-quantitative pull-down assay. Calmodulin bound to the peptides with decreasing affinity order: IQ > preIQ > I-II loop > N-terminal peptide. A peptide containing both preIQ and IQ regions (Leu(1599) - Leu(1668)) bound with approximately 2 mol of calmodulin per peptide. These results support the hypothesis that two molecules of calmodulin can simultaneously bind to the C-terminus of the Cav1.2 channel and modulate its facilitatory and inhibitory activities.
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