Electrochemical and homogeneous electron transfers to the Alzheimer amyloid-beta copper complex follow a preorganization mechanism.
Deciphering the electron transfer reactivity characteristics of amyloid β-peptide copper complexes is an important task in connection with the role they are assumed to play in Alzheimer's disease. A systematic analysis of this question with the example of the amyloid β-peptide copper complex by means of its electrochemical current-potential responses and of its homogenous reactions with electrogenerated fast electron exchanging osmium complexes revealed a quite peculiar mechanism: The reaction proceeds through a small fraction of the complex molecules in which the peptide complex is "preorganized" so as the distances and angles in the coordination sphere to vary minimally upon electron transfer, thus involving a remarkably small reorganization energy (0.3 eV). This preorganization mechanism and its consequences on the reactivity should be taken into account for reactions involving dioxygen and hydrogen peroxide that are considered to be important in Alzheimer's disease through the production of harmful reactive oxygen species.
Balland
Véronique
V
Laboratoire d'Electrochimie Moléculaire, Unité Mixte de Recherche Université-Centre National de la Recherche Scientifique No 7591, Université Paris-Diderot, Bâtiment Lavoisier, 15 Rue Jean de Baïf, 75205 Paris Cedex 13, France.
Hureau
Christelle
C
Savéant
Jean-Michel
JM
D000544:Alzheimer Disease / Q000378:metabolism*; D000595:Amino Acid Sequence; D016229:Amyloid beta-Peptides / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D003300:Copper / Q000737:chemistry*; D004563:Electrochemistry / Q000379:methods; D004579:Electron Transport; D008969:Molecular Sequence Data; D010455:Peptides / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism
D016229:Amyloid beta-Peptides; D010455:Peptides; D003300:Copper