Plasmid DNA damage induced by singlet molecular oxygen released from the naphthalene endoperoxide DHPNO2 and photoactivated methylene blue

Autor(es)

Berra, Carolina Maria ^[1] ; Martins Menck, Carlos Frederico ^[1] ; Martinez, Glaucia Regina ^[2] ; de Oliveira, Carla Santos ^[3] ; Baptista, Mauricio da Silva ^[4] ; Di Mascio, Paolo ^[4]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Inst Ciencias Biomed, Dept Microbiol, BR-05508900 Sao Paulo - Brazil

^[2] Univ Fed Parana, Setor Ciencias Biol, Dept Bioquim & Biol Mol, BR-81531990 Curitiba, Parana - Brazil

^[3] Univ Fed Mato Grosso do Sul, Ctr Ciencias Biol & Saude, Dept Morfofisiol, BR-79070900 Campo Grande, MS - Brazil

^[4] Univ Sao Paulo, Inst Quim, Dept Bioquim, BR-05599970 Sao Paulo - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Química Nova; v. 33, n. 2, p. 279-283, 2010.
• Citações Web of Science: 8

Resumo

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. (AU)