Characterization of damage in gamma-irradiated and OsO4-treated DNA using methoxyamine

• Published in: International journal of radiation biology Vol. 54; no. 5; p. 709
• Main Authors: Liuzzi, M, Talpaert-Borlé, M
• Format: Journal Article
• Language: English
• Published: England 01-11-1988
• Subjects: DNA Damage; DNA, Bacterial - drug effects; DNA, Bacterial - radiation effects; Escherichia coli - genetics; Gamma Rays; Hydroxylamines; Indicators and Reagents; Osmium - pharmacology; Osmium Tetroxide - pharmacology
• ISSN: 0955-3002
• DOI: 10.1080/09553008814552161

Unlabelled and radiolabelled methoxyamine have been used to characterize DNA damage caused by gamma-rays or by the chemical reagent osmium tetroxide (OsO4). Both treatments introduce in DNA a number of methoxyamine-binding sites proportional to the dose. Whereas the number of these sites remains constant after the OsO4 treatment it increases during postirradiation incubation; the postirradiation appearance of methoxyamine-binding sites is enhanced by the presence of methoxyamine. OsO4 treatment and gamma-irradiation also induce the formation of alkali-labile sites in DNA. Whereas the number of these sites remains constant after OsO4 treatment, it increases during postirradiation incubation and an alkaline medium accelerates their formation. A fraction of the alkali-labile sites found in gamma-irradiated DNA is methoxyamine-labile; by contrast, the OsO4-treated DNA is stable in the presence of methoxyamine.