Author(s): Berra, Carolina Maria ; Menck, Carlos Frederico Martins ; Martinez, Glaucia Regina ; Oliveira, Carla Santos de ; Baptista, Maurício da Silva ; Di Mascio, Paolo
Date: 2011
Origin: Oasisbr
Subject(s): Estresse Oxidativo; Dano ao DNA; Oxidative Stress; Oxidative Stress; DNA Damage; Singlet Oxygen
To investigate oxidative lesions and strand breaks induction by singlet molecular oxygen (1O2), supercoiled-DNA plasmid was treated with thermo-dissociated DHPNO2 and photoactivated-methylene blue. DNA lesions were detected by Fpg that cleaves DNA at certain oxidized bases, and T4-endoV, which cleaves DNA at cyclobutane pyrimidine dimers and apurinic/apyrimidinic (AP) sites. These cleavages form open relaxed-DNA structures, which are discriminated from supercoiled-DNA. DHPNO2 or photoactivated-MB treatments result in similar plasmid damage profile: low number of single-strand breaks or AP-sites and high frequency of Fpg-sensitive sites; confirming that base oxidation is the main product for both reactions and that 1O2 might be the most likely intermediate that reacts with DNA.
