DNA triplex stabilization by a δ-carboline derivative tethered to third strand oligonucleotides

A δ-carboline derivative was covalently coupled to a 7 mer oligonucleotide at its 5′- or 3′-end. The stability of triplexes formed from the conjugates and a double-helical target was studied by UV melting experiments. Compared to the unmodified control triple helices, triplexes with the conjugate exhibit a significantly higher stability. However, the degree of stabilization depends on the particular triplex structure formed.