%0 Journal Article
%T Amyloid-£¿-peptide reduces copper(II) to copper(I) independent of its aggregation state
%A OPAZO
%A CARLOS
%A RUIZ
%A FRANCISCA H
%A INESTROSA
%A NIBALDO C
%J Biological Research
%D 2000
%I Sociedad de Biolog¨ªa de Chile
%R 10.4067/S0716-97602000000200012
%X alzheimer£¿s disease (ad) is characterized by the deposition of amyloid b-peptide (a£¿) 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£¿ 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-£¿-peptide on copper reduction. in independent experiments we measured the copper-reducing ability of soluble and fibrillar a£¿1-40 forms by bathocuproine assays. as it was previously observed for the amyloid precursor protein (app), the a£¿ peptide showed copper-reducing ability. the capacity of a£¿ to reduce copper was independent of the aggregation state. finally, the a£¿ peptide derived from the human sequence has a greater effect than the a£¿ peptide derived from the rat sequence, suggesting that histidine 13 may play a role in copper reduction. in agreement with this possibility, the a£¿ peptide reduces less copper in the presence of exogenous histidine
%K a£¿ peptide
%K amyloid fibrils
%K copper reduction
%K oxidative damage
%K alzheimer£¿s disease.
%U http://www.scielo.cl/scielo.php?script=sci_abstract&pid=S0716-97602000000200012&lng=en&nrm=iso&tlng=en