title: Termini generated at the site of the DNA breakage mediated by photoexcited promazines.
abstract: Promazine derivatives are known to be able to photoinduce, in vitro, direct single-strand breaks into DNA (Decuyper et al., Biochem. Pharmac. 33, 4025-4031 (1984]. Using [32P]end labeled DNA fragments, it is demonstrated that this DNA breakage occurs almost regardless of the nucleotide sequence of the DNA. Using 3'-[32P]end or 5'-[32P]end labeled oligonucleotide and enzymatic digestion of the fragments generated, it is demonstrated that the termini generated at the site of the breakage are 5'-phosphate, 3'-phosphate and 3'-termini which are presumed to be 3'-phosphoglycolate. This is consistent with an attack of the sugar moeity of the sugar-phosphate backbone of the DNA by the reactives species generated upon near-u.v. irradiation of promazine derivatives.
mesh_terms: D004247:DNA / Q000528:radiation effects*; D004591:Electrophoresis, Polyacrylamide Gel; D005720:Gamma Rays; D006878:Hydroxides; D017665:Hydroxyl Radical; D010744:Phosphoric Monoester Hydrolases / Q000494:pharmacology; D010777:Photochemistry; D011395:Promazine / Q000494:pharmacology*
chemical_list: D006878:Hydroxides; D017665:Hydroxyl Radical; D004247:DNA; D010744:Phosphoric Monoester Hydrolases; D011395:Promazine