Thermodynamic and structural properties of the specific binding between Ag+ ion and C:C mismatched base pair in duplex DNA to form C-Ag-C metal-mediated base pair

► Adding the Ag+ ion specifically stabilized only the duplex with the C:C base pair. ► The Ag+ ion bound with the C:C base pair at 1:1 molar ratio. ► The association constant for the Ag+ ion binding with the C:C base pair was 106 M−1. ► The Ag+ ion may bind with the N3 positions of the C:C base pair. ► The Ag+ ion binding did not distort the higher-order structure of the duplex.