Link between Affinity and Cu(II) Binding Sites to Amyloid-β Peptides Evaluated by a New Water-Soluble UV–Visible Ratiometric Dye with a Moderate Cu(II) Affinity

Amandine Conte-Daban (1, 2) , Valentina Borghesani (2, 1) , Stéphanie Sayen (3) , Emmanuel Guillon (3) , Yves Journaux (4) , Geoffrey Gontard (4) , Laurent Lisnard (4) , Christelle Hureau (1, 2)

1 LCC - Laboratoire de chimie de coordination
2 Toulouse INP - Institut National Polytechnique (Toulouse)
3 ICMR - Institut de Chimie Moléculaire de Reims - UMR 7312
4 IPCM - Institut Parisien de Chimie Moléculaire

Being able to easily determine the Cu(II) affinity for biomolecules of moderate affinity is important. Such biomolecules include amyloidogenic peptides, such as the well-known amyloid-β peptide involved in Alzheimer’s disease. Here, we re-port the synthesis of a new water soluble ratiometric Cu(II) dye with a moderate affinity (10^9 M-1 at pH 7.1) and the characterizations of the Cu(II) corresponding complex by X-ray crystallography, EPR and XAS spectroscopic methods. UV-Vis competition were performed on the Aβ peptide as well as on a wide series of modified peptides, leading to an affinity value of 1.6 10^9 M-1 at pH 7.1 for the Aβ peptide and to a coordination model for the Cu(II) site within the Aβ peptide that agrees with the one mostly accepted currently.

Domaines: Chimie de coordination; Biochimie [q-bio.BM]

Amandine Conte-Daban, Valentina Borghesani, Stéphanie Sayen, Emmanuel Guillon, Yves Journaux, et al.. Link between Affinity and Cu(II) Binding Sites to Amyloid-β Peptides Evaluated by a New Water-Soluble UV–Visible Ratiometric Dye with a Moderate Cu(II) Affinity. Analytical Chemistry, 2017, 89 (3), pp.2155-2162. ⟨10.1021/acs.analchem.6b04979⟩. ⟨hal-01586442⟩