title: Near-ultraviolet light-induced strand breaks in DNA pretreated with the carcinogen, N-acetoxy-2-acetylaminofluorene.
abstract: Neutral sucrose gradients of supercoiled DNA (phiX-174 RF I) were used to measure the in vitro production of strand breaks by the carcinogen, N-acetoxy-2-acetylaminofluorene (AcO-AAF). Treatment with AcO-AAF in 10% dimethyl sulfoxide did not directly yield strand breaks. Breaks in relatively low yield appeared after alkali treatment (pH 13, 60 min) of the RF I previously reacted with AcO-AAF. The DNA treated with AcO-AAF was sensitive to single-strand breakage by 303 nm near-ultraviolet light under neutral conditions. The greater the prior AcO-AAF treatment, the greater the sensitivity to 303 nm light. Post-irradiation alkali treatment greatly enhanced the light-induced strand breakage.
mesh_terms: D000099:Acetoxyacetylaminofluorene; D001665:Binding Sites; D003090:Coliphages / Q000032:analysis*; D004267:DNA Viruses / Q000032:analysis; D004277:DNA, Single-Stranded / Q000528:radiation effects; D004279:DNA, Viral / Q000528:radiation effects*; D004121:Dimethyl Sulfoxide; D005449:Fluorenes; D006863:Hydrogen-Ion Concentration; D009690:Nucleic Acid Conformation; D011830:Radiation Effects; D013997:Time Factors; D014466:Ultraviolet Rays
chemical_list: D004277:DNA, Single-Stranded; D004279:DNA, Viral; D005449:Fluorenes; D000099:Acetoxyacetylaminofluorene; D004121:Dimethyl Sulfoxide