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Updated: Jun 20, 2026

Pull-down of Calmodulin-binding Proteins
Published on: January 23, 2012
Directly observed hydrogen bonds at calcium-binding-sites of calmodulin in solution relate to affinity of the
Nenad Juranić1, Elena Atanasova, Slobodan Macura
1Departments of Biochemistry and Molecular Biology, Mayo College of Medicine, Mayo Clinic and Foundation, Rochester, MN 55905, USA. juranic.nenad@mayo.edu
Abstract:
Molecular tuning to calcium-binding in the EF-hand motif of holo-calmodulin was studied in solution by NMR (h3)J(NC') H-bond couplings. In the N-terminus lobe of holo-calmodulin, the glutamate crucial for Ca(2+) coordination has network of H-bonds weaker than inferred from the X-ray crystal structure. This glutamate at position 12 appears shifted away from the Ca(2+) preferred coordination, which can explain the lower affinity of the calcium-binding to the N-terminus with respect to C-terminus EF hands.
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