Amyloid-beta-peptide reduces copper(II) to copper(I) independent of its aggregation state
Biol. Res
;
33(2): 125-131, 2000. tab, graf, ilus
Artículo
en Inglés
| LILACS
| ID: lil-443670
ABSTRACT
Alzheimer's disease (AD) is characterized by the deposition of amyloid beta-peptide (A beta) and neuronal degeneration in brain regions involved in learning and memory. One of the leading etiologic hypotheses regarding AD is the involvement of free radical-mediated oxidative stress in neuronal degeneration. Recent evidence suggests that metals concentrated in amyloid deposits may contribute to the oxidative insults observed in AD-affected brains. We hypothesized that A beta peptide in the presence of copper enhances its neurotoxicity generating free radicals via copper reduction. In the present study, we have examined the effect of the aggregation state of amyloid-beta-peptide on copper reduction. In independent experiments we measured the copper-reducing ability of soluble and fibrillar A beta(1-40) forms by bathocuproine assays. As it was previously observed for the amyloid precursor protein (APP), the A beta peptide showed copper-reducing ability. The capacity of A beta to reduce copper was independent of the aggregation state. Finally, the A beta peptide derived from the human sequence has a greater effect than the A beta peptide derived from the rat sequence, suggesting that histidine 13 may play a role in copper reduction. In agreement with this possibility, the A beta peptide reduces less copper in the presence of exogenous histidine.
Texto completo:
Disponible
Índice:
LILACS (Américas)
Asunto principal:
Péptidos beta-Amiloides
/
Cobre
/
Enfermedad de Alzheimer
Tipo de estudio:
Estudio de etiología
Límite:
Humanos
Idioma:
Inglés
Revista:
Biol. Res
Asunto de la revista:
Biologia
Año:
2000
Tipo del documento:
Artículo
País de afiliación:
Chile
Institución/País de afiliación:
Pontificia Universidad Católica de Chile/CL
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