| Registro completo |
| Provedor de dados: |
BJMBR
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| País: |
Brazil
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| Título: |
Ghost protein damage by peroxynitrite and its protection by melatonin
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| Autores: |
Di Mascio,P.
Dewez,B.
Garcia,C.R.S.
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| Data: |
2000-01-01
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| Ano: |
2000
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| Palavras-chave: |
Peroxynitrite
Melatonin
Spectrin
Protein
Ghost
Thiols
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| Resumo: |
We have studied the effect of peroxynitrite (ONOO-) on the membrane cytoskeleton of red blood cells and its protection by melatonin. Analysis of the protein fraction of the preparation by SDS-PAGE revealed a dose-dependent (0-600 µM ONOO-) disappearance at pH 7.4 of the main proteins: spectrin, band 3, and actin, with the concomitant formation of high-molecular weight aggregates resistant to reduction by ß-mercaptoethanol (2%) at room temperature for 20 min. These aggregates were not solubilized by 8 M urea. Incubation of the membrane cytoskeleton with ONOO- was characterized by a marked depletion of free sulfhydryl groups (50% at 250 µM ONOO-). However, a lack of effect of ß-mercaptoethanol suggests that, under our conditions, aggregate formation is not mediated only by sulfhydryl oxidation. The lack of a protective effect of the metal chelator diethylenetriaminepentaacetic acid confirmed that ONOO--induced oxidative damage does not occur only by a transition metal-dependent mechanism. However, we demonstrated a strong protection against cytoskeletal alterations by desferrioxamine, which has been described as a direct scavenger of the protonated form of peroxynitrite. Desferrioxamine (0.5 mM) also inhibited the loss of tryptophan fluorescence observed when the ghosts were treated with ONOO-. Glutathione, cysteine, and Trolox® (1 mM), but not mannitol (100 mM), were able to protect the proteins against the effect of ONOO- in a dose-dependent manner. Melatonin (0-1 mM) was especially efficient in reducing the loss of spectrin proteins when treated with ONOO- (90% at 500 µM melatonin). Our findings show that the cytoskeleton, and in particular spectrin, is a sensitive target for ONOO-. Specific antioxidants can protect against such alterations, which could seriously impair cell dynamics and generate morphological changes.
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| Tipo: |
Info:eu-repo/semantics/article
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| Idioma: |
Inglês
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| Identificador: |
http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2000000100002
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| Editor: |
Associação Brasileira de Divulgação Científica
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| Relação: |
10.1590/S0100-879X2000000100002
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| Formato: |
text/html
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| Fonte: |
Brazilian Journal of Medical and Biological Research v.33 n.1 2000
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| Direitos: |
info:eu-repo/semantics/openAccess
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