title: Alkaline labilization of DNA photosensitized by promazine derivatives.
abstract: Superhelical pBR322 DNA has been photosensitized in the presence of various promazine derivatives. Agarose gel electrophoresis of the photosensitized DNA reveals that true single-strand breaks are induced during irradiation. Alkaline treatment of the photosensitized DNA with a subsequent alkaline agarose gel electrophoresis demonstrates that in addition to true single-strand breaks, these drugs can induce alkali-labile lesions. Although true single-strand breaks are induced randomly into a 5'-[32P]-end labeled pBR322 DNA fragments, the alkaline-labile alterations are located specifically at the level of guanine residues. A strong correlation seems to exist between the visualization of this labilization and the induction of a covalent photoadduct on guanine by the photosensitization mediated by PZ.
authors: Laboratory of Experimental Physics, University of Liège, Belgium.
authors: J
authors: J
authors: Piette
authors: A
authors: A
authors: Van de Vorst
mesh_terms: D000468:Alkalies; D004247:DNA / Q000187:drug effects* / Q000528:radiation effects; D004249:DNA Damage; D004587:Electrophoresis, Agar Gel; D004591:Electrophoresis, Polyacrylamide Gel; D011395:Promazine / Q000494:pharmacology*
chemical_list: D000468:Alkalies; D004247:DNA; D011395:Promazine