Mechanism of site-specific psoralen photoadducts formation in triplex DNA directed by psoralen-conjugated oligonucleotides

Triplex structures were generated by targeting a DNA duplex with photoreactive psoralen molecule (psoTFO), where TFO is triplex-formation oligonucleotides, of different lengths in order to investigate the mechanism of photoadduct-formation by psoralen photo-cross-linking. Results demonstrated that UV radiation of triplexes formed between a psoTFO and a DNA duplex generated two distinct groups of psoralen photoadducts, monoadducts and psoralen interstand cross-link products.