title: Formation of cyclobutane thymine dimers from UVA photosensitization of pyridopsoralen monoadducted DNA.
abstract: The present report provides evidence that thymine dimerization can be UVA photosensitized at a tetranucleotide, 5'-TATT-3', by a 7-methyl-pyrido(3,4-c)psoralen monoadduct in DNA. The efficiency of the photoprocess depends on the tetranucleotide flanking sequences. These results demonstrate that one DNA lesion can originate the contiguous formation of a second type of lesion and emphasize the sequence-specific response to interaction of drugs with DNA. Results are related to the sensitivity of DNA to 1,10-phenanthroline-cuprous ion complex nucleolytic activity and discussed in terms of the major role of local deformability of DNA in interaction with ligands.
authors: Departmento de Bioquimica, Universidade de Sao Paulo, Brazil.
authors: L A
authors: LA
authors: Guillo
authors: B
authors: B
authors: Beylot
authors: P
authors: P
authors: Vigny
authors: A
authors: A
authors: Spassky
mesh_terms: D000818:Animals; D001483:Base Sequence; D002417:Cattle; D004247:DNA / Q000378:metabolism* / Q000528:radiation effects*; D018736:DNA Adducts / Q000378:metabolism / Q000528:radiation effects*; D004249:DNA Damage; D011564:Furocoumarins / Q000378:metabolism* / Q000633:toxicity; D008969:Molecular Sequence Data; D009153:Mutagens / Q000378:metabolism* / Q000633:toxicity; D017319:Photosensitizing Agents / Q000378:metabolism* / Q000633:toxicity; D011740:Pyrimidine Dimers / Q000096:biosynthesis*; D013941:Thymine / Q000378:metabolism*; D014466:Ultraviolet Rays
chemical_list: D018736:DNA Adducts; D011564:Furocoumarins; D009153:Mutagens; D017319:Photosensitizing Agents; D011740:Pyrimidine Dimers; C044264:pyrido(3,4-c)-7-methylpsoralen; D004247:DNA; D013941:Thymine