Development of antiparallel-type triplex-forming oligonucleotides containing quinoline derivatives capable of recognizing a T-A base pair in a DNA duplex.

A triplex-forming oligonucleotide (TFO) can bind to genomic DNA and inhibit the expression of genes with specific sequences. However, to date, there have been a few reports of modified bases in antiparallel TFOs that can recognize and strongly bind to T-A base pairs. In this study, we introduced several quinoline derivatives into antiparallel TFOs to develop modified bases that can recognize the T-A base pair and evaluated their ability to form triplexes and to discriminate between base pairs. The introduction of 2-acetamido-6-aminoquinoline6DAQac) into an antiparallel TFO allowed the selective recognition of a T-A base pair at both low and high salt concentrations.