Alzheimer's β-amyloid peptide as a source of neurotoxic free radicals: the role of structural effects

This mini review gives a brief overview over the oxidation mechanism of methionine (Met), relevant for processes which may lead to the oxidation of amyloid beta-peptide (betaAP), involved in the pathogenesis of Alzheimer's disease. The Cu(II) -catalysed oxidation of C-terminal Met35 in betaAP depends on the secondary structure of the peptide. That seems to be the key to the known propensities of this peptide to form reactive oxygen species and free radicals. The pro-oxidant character of betaPAP is not associated with its beta-sheet insoluble form. On the contrary, the alpha-helically organised structure is responsible for betaAP redox-related cytotoxicity.