Use este identificador para citar ou linkar para este item: http://repositorio.bc.ufg.br/handle/ri/15256
Tipo do documento: Artigo
Título: Electron paramagnetic resonance study of lipid and protein membrane components of erythrocytes oxidized with hydrogen peroxide
Autor: Mendanha Neto, Sebastião Antônio
Anjos, Jorge Luiz Vieira dos
Silva, Adolfo Henrique de Moraes
Alonso, Antonio
Abstract: Electron paramagnetic resonance (EPR) spectroscopy of spin labels was used to monitor membrane dynamic changes in erythrocytes subjected to oxidative stress with hydrogen peroxide (H2O2). The lipid spin label, 5-doxyl stearic acid, responded to dramatic reductions in membrane fluidity, which was correlated with increases in the protein content of the membrane. Membrane rigidity, associated with the binding of hemoglobin (Hb) to the erythrocyte membrane, was also indicated by a spinlabeled maleimide, 5-MSL, covalently bound to the sulfhydryl groups of membrane proteins. At 2% hematocrit, these alterations in membrane occurred at very low concentrations of H2O2 (50 μM) after only 5 min of incubation at 37°C in azide phosphate buffer, pH 7.4. Lipid peroxidation, suggested by oxidative hemolysis and malondialdehyde formation, started at 300 μM H2O2 (for incubation of 3 h), which is a concentration about six times higher than those detected with the probes. Ascorbic acid and α-tocopherol protected the membrane against lipoperoxidation, but did not prevent the binding of proteins to the erythrocyte membrane. Moreover, the antioxidant (+)-catechin, which also failed to prevent the cross-linking of cytoskeletal proteins with Hb, was very effective in protecting erythrocyte ghosts from lipid peroxidation induced by the Fenton reaction. This study also showed that EPR spectroscopy can be useful to assess the molecular dynamics of red blood cell membranes in both the lipid and protein domains and examine oxidation processes in a system that is so vulnerable to oxidation.
Palavras-chave: Electron paramagnetic resonance
Spin label
Erythrocyte
Membrane fluidity
Protein oxidation
Membrane oxidation
País: Brasil
Unidade acadêmica: Instituto de Física - IF (RG)
Citação: MENDANHA, S. A.; ANJOS, J. L. V.; SILVA, A. H. M.; ALONSO, A. Electron paramagnetic resonance study of lipid and protein membrane components of erythrocytes oxidized with hydrogen peroxide. Brazilian Journal of Medical and Biological Research, Ribeirão Preto, v. 45, n. 6, p. 473-481, May 2012.
Tipo de acesso: Acesso Aberto
Identificador do documento: 10.1590/S0100-879X2012007500050
Identificador do documento: 10.1590/S0100-879X2012007500050
URI: http://repositorio.bc.ufg.br/handle/ri/15256
Data de publicação: Mai-2012
Aparece nas coleções:IF - Artigos publicados em periódicos

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