title: Zn induced structural aggregation patterns of β-amyloid peptides by first-principle simulations and XAS measurements.
abstract: We show in this paper that in the presence of Zn ions a peculiar structural aggregation pattern of β-amyloid peptides in which metal ions are sequentially coordinated to either three or four histidines of nearby peptides is favored. To stabilize this configuration a deprotonated imidazole ring from one of the histidines forms a bridge connecting two adjacent Zn ions. Though present in zeolite imidazolate frameworks, remarkably in biological compounds this peculiar Zn-imidazolate-Zn topology is only found in enzymes belonging to the Cu,Zn-superoxide dismutase family in the form of an imidazolate bridging Cu and Zn. The results we present are obtained by combining X-ray absorption spectroscopy experimental data with detailed first-principle molecular dynamics simulations.
authors.affiliation: University of Udine, Department of Chemistry, Physics and Environment, via del Cotonificio 108, 33100 Udine, Italy.
authors.forename: Paolo
authors.initials: P
authors.lastname: Giannozzi
authors.forename: Karl
authors.initials: K
authors.lastname: Jansen
authors.forename: Giovanni
authors.initials: G
authors.lastname: La Penna
authors.forename: Velia
authors.initials: V
authors.lastname: Minicozzi
authors.forename: Silvia
authors.initials: S
authors.lastname: Morante
authors.forename: Giancarlo
authors.initials: G
authors.lastname: Rossi
authors.forename: Francesco
authors.initials: F
authors.lastname: Stellato
mesh_terms: D016229:Amyloid beta-Peptides / Q000737:chemistry* / Q000378:metabolism; D006639:Histidine / Q000737:chemistry; D007093:Imidazoles / Q000737:chemistry; D056004:Molecular Dynamics Simulation; D056928:X-Ray Absorption Spectroscopy; D015032:Zinc / Q000737:chemistry*
chemical_list: D016229:Amyloid beta-Peptides; D007093:Imidazoles; D006639:Histidine; C029899:imidazole; D015032:Zinc