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

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.

Bibliographic Details

Main Authors:	Berra,Carolina Maria, Menck,Carlos Frederico Martins, Martinez,Glaucia Regina, Oliveira,Carla Santos de, Baptista,Maurício da Silva, Di Mascio,Paolo
Format:	Digital revista
Language:	English
Published:	Sociedade Brasileira de Química 2010
Online Access:	http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0100-40422010000200009
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