Ionic microenvironmental effects on triplex DNA stabilization: Cationic counterion effects on poly(dT)·poly(dA)·poly(dT)

► First detailed investigation of several metal and ammonium ion effects on triplex DNA stability. ► Number of positive charge and size of cations influenced triplex DNA stability. ► Differential effect of metal ions on facilitating triplex and duplex DNA formation. ► Cation release on triplex/duplex DNA melting calculated. ► Conformational changes on triplex DNA formation by Li and ammonium ions studied.