title: Cu(II) affinity for the Alzheimer's peptide: tyrosine fluorescence studies revisited.
abstract: Copper(II) binding to the amyloid-β peptide has been proposed to be a key event in the cascade leading to Alzheimer's disease. As a direct consequence, the strength of the Cu(II) to Aβ interaction, that is, the Cu(II) affinity of Aβ, is a very important parameter to determine. Because Aβ peptide contain one Tyr fluorophore in its sequence and because Cu(II) does quench Tyr fluorescence, fluorescence measurements appear to be a straightforward way to obtain this parameter. However, this proved to be wrong, mainly because of data misinterpretation in some previous studies that leads to a conflicting situation. In the present paper, we have investigated in details a large set of fluorescence data that were analyzed with a new method taking into account the presence of two Cu(II) sites and the inner-filter effect. This leads to reinterpretation of the published data and to the determination of a unified affinity value in the 10(10) M(-1) range.
authors.affiliation: CNRS, LCC (Laboratoire de Chimie de Coordination), 205 Route de Narbonne, BP 44099, F-31077 Toulouse, Cedex 4, France.
authors.forename: Bruno
authors.initials: B
authors.lastname: Alies
authors.forename: Emelyne
authors.initials: E
authors.lastname: Renaglia
authors.forename: Malgorzata
authors.initials: M
authors.lastname: Rózga
authors.forename: Wojciech
authors.initials: W
authors.lastname: Bal
authors.forename: Peter
authors.initials: P
authors.lastname: Faller
authors.forename: Christelle
authors.initials: C
authors.lastname: Hureau
mesh_terms: D000544:Alzheimer Disease / Q000378:metabolism*; D000595:Amino Acid Sequence; D016229:Amyloid beta-Peptides / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D005456:Fluorescent Dyes / Q000378:metabolism*; D006801:Humans; D051379:Mice; D008969:Molecular Sequence Data; D011485:Protein Binding / Q000502:physiology; D014443:Tyrosine / Q000378:metabolism*
chemical_list: D016229:Amyloid beta-Peptides; D005456:Fluorescent Dyes; D014443:Tyrosine