Manganese ions induce H2O2 generation at the ubiquinone binding site of mitochondrial complex II.
Arch Biochem Biophys
; 580: 75-83, 2015 Aug 15.
Article
em En
| MEDLINE
| ID: mdl-26116786
ABSTRACT
Manganese-induced toxicity has been recently associated with an increased ROS generation from mitochondrial complex II (succinateubiquinone oxidoreductase). To achieve a deeper mechanistic understanding how divalent manganese ions (Mn(2+)) could stimulate mitochondrial ROS production we performed investigations with bovine heart submitochondrial particles (SMP). In succinate fueled SMP, the Mn(2+) induced hydrogen peroxide (H2O2) production was blocked by the specific complex II ubiquinone binding site (IIQ) inhibitor atpenin A5 while a further downstream block at complex III increased the rate markedly. This suggests that site IIQ was the source of the reactive oxygen species. Moreover, Mn(2+) ions also accelerated the rate of superoxide dismutation, explaining the general increase in the measured rates of H2O2 production and an attenuation of direct superoxide detection.
Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Partículas Submitocôndricas
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Complexo II de Transporte de Elétrons
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Membranas Mitocondriais
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Peróxido de Hidrogênio
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Manganês
Limite:
Animals
Idioma:
En
Ano de publicação:
2015
Tipo de documento:
Article