Data/hora: 10/06/2024 08:58:11

Provedor de dados: | 56
País: | Brazil
Título: | Superoxide: a two-edged sword
Data: | 1997-02-01
Ano: | 1997
Palavras-chave: | NADPH oxidase; Superoxide; Oxidative stress; Antioxidant; Regulation; Host defense.
Resumo: | Superoxide (O2-) is the compound obtained when oxygen is reduced by one electron. For a molecule with an unpaired electron, O2- is surprisingly inert, its chief reaction being a dismutation in which it reacts with itself to form H2O2 and oxygen. The involvement of O2- in biological systems was first revealed by the discovery in 1969 of superoxide dismutase, an enzyme that catalyzes the dismutation of O2-. Since then it has been found that biological systems produce a bewildering variety of reactive oxidants, all but a few arising ultimately from O2-. These oxidants include O2- itself, H2O2 and alkyl peroxides, hydroxyl radical and other reactive oxidizing radicals, oxidized halogens and halamines, singlet oxygen, and peroxynitrite. These various oxidants are able to damage molecules in their environment, and are therefore very dangerous. They are thought to participate in the pathogenesis of a number of common diseases, including among others malignancy, by their ability to mutate the genome, and atherosclerosis, by their capacity for oxidizing lipoproteins. Their properties are put to good use, however, in host defense, where they serve as microbicidal and parasiticidal agents, and in biological signalling, where their liberation in small quantities results in redox-mediated changes in the functions of enzymes and other proteins
Tipo: | Info:eu-repo/semantics/other
Idioma: | Inglês
Identificador: | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X1997000200001
Editor: | Associação Brasileira de Divulgação Científica
Relação: | 10.1590/S0100-879X1997000200001
Formato: | text/html
Fonte: | Brazilian Journal of Medical and Biological Research  v.30 n.2 1997
Fonte: | info:eu-repo/semantics/openAccess