Methionine residue 35 is critical for the oxidative stress and neurotoxic properties of Alzheimer’s amyloid β-peptide 1–42

Abstract

Amyloid β-peptide 1–42 [Aβ(1–42)] is central to the pathogenesis of Alzheimer’s disease (AD), and the AD brain is under intense oxidative stress. Our laboratory combined these two aspects of AD into the Aβ-associated free radical oxidative stress model for neurodegeneration in AD brain. Aβ(1–42) caused protein oxidation, lipid peroxidation, reactive oxygen species formation, and cell death in neuronal and synaptosomal systems, all of which could be inhibited by free radical antioxidants. Recent studies have been directed at discerning molecular mechanisms by which Aβ(1–42)-associated free radical oxidative stress and neurotoxicity arise. The single methionine located in residue 35 of Aβ(1–42) is critical for these properties. This review presents the evidence supporting the role of methionine in Aβ(1–42)-associated free radical oxidative stress and neurotoxicity. This work is of obvious relevance to AD and provides a coupling between the centrality of Aβ(1–42) in the pathogenesis of AD and the oxidative stress under which the AD brain exists.