Sequence specific damage of DNA induced by reducing sugars.

Reducing sugars induced alkali-labile sites in DNA. The DNA reacted with D-fructose 6-phosphate or D-fructose in the presence of Cu2+ was cleaved by the treatment with aqueous piperidine at 90 degrees C for 30 min. Alkali-labile sites were induced frequently at the pyrimidine residues, especially at the pyrimidine residues in pyrimidine-purine (5'----3') sequences. Transition metal ions such as Cu2+ and oxygen radicals such as hydrogen peroxide were possibly involved in the induction of alkali-labile sites.