Lesões em DNA induzidas pela autoxidação de S(IV) na presença de íons metálicos de transição

Abstract

Recebido em 22/6/05; aceito em 18/11/05; publicado na web em 14/6/06 DNA DAMAGE INDUCED BY THE AUTOXIDATION OF S(IV) IN THE PRESENCE OF TRANSITION METAL IONS. The oxidation of sulfite catalyzed by transition metal ions produces reactive oxysulfur species that can damage plasmid and isolated DNA in vitro. Among the four DNA bases, guanine is the most sensitive to one-electron oxidation promoted by the species formed in the autoxidation of sulfite (HSO 5 -, HO • , SO 3 •-, SO 4 •-and SO 5•-) due to its low reduction potential and ability to bind transition metal ions capable to catalyze oxidative processes. Some oxidative DNA lesions are promutagenic and oxidative DNA damage is proposed to play a crucial role in certain human pathologies, including cancer.

DNA damage by sulfite autoxidation catalyzed by cobalt complexes

“…2, 3 Autoxidation of S(IV) catalyzed by transition metal ions can also generate oxysulfur radicals, which might be potentially harmful to biological molecules. [4][5][6][7][8][9][10] Cobalt is an essential element in the human diet. It is part of vitamin B 12 , and plays a key role in the biosynthesis of this essential vitamin.…”