[Study of the structure and mechanism of action of troponin C and calmodulin by "protein" engineering].

The structure, properties and action mechanisms of troponin C and calmodulin are reviewed. The primary and tertiary structures of calcium-binding proteins and the mechanisms of Ca2+ binding are analyzed. The methods used for investigating the functional activity of Ca-binding proteins are compared. Molecular biology approaches for analyzing the role of various ligands in Ca2+ binding are described. The role of alpha-helices in the maintenance of the overall structure, Ca2+ binding and calmodulin and troponin C interaction with target proteins is discussed. Mutations directed at the change of the electric charge and hydrophobicity of calmodulin and troponin C are described and compared. Data on the incorporation of Cys residues into calmodulin and troponin C structure are presented. The use of Cys-containing mutants of Ca-binding proteins for the study of conformational changes and protein-protein interaction is analyzed.