Divalent Cation Dependent Conformations of Brain Calmodulin Detected by ¹H NMR

Abstract

The effects of the Ca²⁺, Mg²⁺, Zn²⁺, Cd²⁺, Hg²⁺ and Mn²⁺ on the conformation of calmodulin (CaM) have been tested by using 400 MHz ¹H NMR. In the aromatic region of the spectrum of CaM with a one molar ratio of cation per CaM, Zn²⁺, Cd²⁺, Hg²⁺ and Mn²⁺ induced spectral changes which were very similar to those seen for Ca²⁺. However, the Mg²⁺-induced change was different. These results are consistent with our pharmacological findings on divalent cations.