Investigation of C-Cadherin mechanical properties by Molecular Dynamics

The mechanical stability of cell adhesion protein Cadherin with explicit model of water is studied by the method of molecular dynamics. The protein in apo-form and with the ions of different types $(Ca^{2+}, Mg^{2+}, Na^{+}, K^{+})$ was unfolding with a constant speed by applying the force to the ends. Eight independent experiments were done for each form of the protein. It was shown that univalent ions stabilize the structure less than bivalent one under mechanical unfolding of the protein. A model system composed of two amino acids and the metal ion between them demonstrates properties similar to that of the cadherin in the stretching experiments. The systems with potassium and sodium ions have less mechanical stability then the systems with calcium and magnesium ions.