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

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• 作者：Amandine Conte-Daban ; Valentina Borghesani ; Stéphanie Sayen ; Emmanuel Guillon ; Yves Journaux ; Geoffrey Gontard ; Laurent LisnardChristelle Hureau
• 刊名：Analytical Chemistry
• 出版年：2017
• 出版时间：February 7, 2017
• 年：2017
• 卷：89
• 期：3
• 页码：2155-2162
• 全文大小：404K
• ISSN：1520-6882

文摘

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 report the synthesis of a new water-soluble ratiometric Cu(II) dye with a moderate affinity (10⁹ 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 was performed on the Aβ peptide as well as on a wide series of modified peptides, leading to an affinity value of 1.6 × 10⁹ 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.