Methionine regulates copper/hydrogen peroxide oxidation products of Aβ

Abstract

Metal-catalysed oxidation (MCO) may play a causative role in the pathogenesis of Alzheimer's disease (AD). Amyloid β peptide (Aβ), the major biomarker of AD, in the presence of copper ions reduces Cu2+ to Cu+ and catalyses the formation of H2O2 that subsequently induces radicals through Fenton chemistry. Aβ is also subject to attack by free radicals, where the presence of Cu2+ in conjunction with H2O2 catalyses oxygenation, primarily at the methionine sulfur atom. This work investigates MCO of Aβ, to gain further insight into the role of oxidative stress in AD. By combining a fluorescence assay with gel electrophoresis to monitor MCO reactions of Aβ (1-28) in the presence and absence of meth..