title: Cu(II)-Zn(II) Cross-Modulation in Amyloid-Beta Peptide Binding: An X-ray Absorption Spectroscopy Study.
abstract: In this work we analyze at a structural level the mechanism by which Cu(II) and Zn(II) ions compete for binding to the Aβ peptides that is involved in the etiology of Alzheimer's disease. We collected X-ray absorption spectroscopy data on samples containing Aβ with Cu and Zn at different concentration ratios. We show that the order in which metals are added to the peptide solution matters and that, when Zn is added first, it prevents Cu from binding. On the contrary, when Cu is added first, it does not (completely) prevent Zn binding to Aβ peptides. Our analysis suggests that Cu and Zn ions are coordinated to different numbers of histidine residues depending on the [ion]:[peptide] concentration ratio.
authors.affiliation: Department of Physics and INFN, University of Rome , Tor Vergata, Rome 00133, Italy.
authors.forename: Emiliano
authors.initials: E
authors.lastname: De Santis
authors.affiliation: Department of Physics and INFN, University of Rome , Tor Vergata, Rome 00133, Italy.
authors.forename: Velia
authors.initials: V
authors.lastname: Minicozzi
authors.affiliation: Observatoire des Sciences de l'Univers de Grenoble , Grenoble 38400, France.
authors.forename: Olivier
authors.initials: O
authors.lastname: Proux
authors.affiliation: Department of Physics and INFN, University of Rome , Tor Vergata, Rome 00133, Italy.|Centro Fermi , Rome 00184, Italy.
authors.forename: Giancarlo
authors.initials: G
authors.lastname: Rossi
authors.affiliation: Department of Chemistry, University of Pittsburgh , Pittsburgh, Pennsylvania 15260, United States.
authors.forename: K Ishara
authors.initials: KI
authors.lastname: Silva
authors.affiliation: Department of Chemistry, University of Pittsburgh , Pittsburgh, Pennsylvania 15260, United States.
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Lawless
authors.affiliation: Department of Physics and INFN, University of Rome , Tor Vergata, Rome 00133, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Stellato
authors.affiliation: Department of Chemistry, University of Pittsburgh , Pittsburgh, Pennsylvania 15260, United States.
authors.forename: Sunil
authors.initials: S
authors.lastname: Saxena
authors.affiliation: Department of Physics and INFN, University of Rome , Tor Vergata, Rome 00133, Italy.
authors.forename: Silvia
authors.initials: S
authors.lastname: Morante
mesh_terms: D016229:Amyloid beta-Peptides / Q000737:chemistry*; D001665:Binding Sites; D003300:Copper / Q000737:chemistry*; D056928:X-Ray Absorption Spectroscopy; D015032:Zinc / Q000737:chemistry*
chemical_list: D016229:Amyloid beta-Peptides; D003300:Copper; D015032:Zinc