title: Al(3+) interaction sites of calmodulin and the Al(3+) effect on target binding of calmodulin.
abstract: The interaction between calmodulin (CaM) and Al(3+) was studied by spectroscopic methods. Heteronuclear two-dimensional NMR data indicated that peaks related to the both lobes and middle of the central helix of CaM are largely affected by Al(3+). But chemical shift perturbation suggested that overall conformation of Ca(2+)-loaded CaM is not changed by Al(3+) binding. It is thought that Al(3+) interaction to the middle of the central helix is a key for the property of CaM's target recognition. If the structure and/or flexibility of the central helix are/is changed by Al(3+), target affinity to CaM must be influenced by Al(3+). Thus, we performed surface plasmon resonance experiments to observe the effect of Al(3+) on the target recognition by CaM. The data clearly indicated that target affinity to CaM is reduced by addition of Al(3+). All the results presented here support a hypothesis that Al(3+) may affect on the Ca(2+) signaling pathway in cells.
authors.affiliation: Japan Advanced Institute of Science and Technology, 1-1 Asahidai, Tatsunokuchi, Ishikawa 923-1292, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Kurita
authors.forename: Akiko
authors.initials: A
authors.lastname: Nakatomi
authors.forename: Hideto
authors.initials: H
authors.lastname: Shimahara
authors.forename: Michio
authors.initials: M
authors.lastname: Yazawa
authors.forename: Shin-Ya
authors.initials: SY
authors.lastname: Ohki
mesh_terms: D000535:Aluminum / Q000032:analysis / Q000737:chemistry*; D001665:Binding Sites; D002147:Calmodulin / Q000032:analysis / Q000737:chemistry*; D004578:Electron Spin Resonance Spectroscopy; D019906:Nuclear Magnetic Resonance, Biomolecular; D011485:Protein Binding
chemical_list: D002147:Calmodulin; D000535:Aluminum