title: Bioinorganic chemistry of synucleinopathies: deciphering the binding features of Met motifs and His-50 in AS-Cu(I) interactions.
abstract: The aggregation of alpha-synuclein (AS) is a critical step in the etiology of Parkinson's disease (PD) and other neurodegenerative synucleinopathies. This process is selectively enhanced by copper in vitro and the interaction is proposed to play a potential role in vivo. Presently, the identity of the Cu(I) binding sites in AS and their relative affinities are under debate. In this work we have addressed unresolved details related to the structural binding specificity and affinity of Cu(I) to full-length AS. We demonstrated conclusively that: (i) the binding preferences of Cu(I) for the Met-binding sites at the N- (Kd=20 μM) and C-terminus (Kd=270 μM) of AS are widely different: (ii) the imidazole ring of His-50 acts as an effective anchoring residue (Kd=50 μM) for Cu(I) binding to AS; and (iii) no major structural rearrangements occur in the protein upon Cu(I) binding. Overall, our work shows that Cu(I) binding to the N- and C-terminal regions of AS are two independent events, with substantial differences in their affinities, and suggest that protein oxidative damage derived from a misbalance in cellular copper homeostasis would target preferentially the N-terminal region of AS. This knowledge is key to understanding the structural-aggregation basis of the copper catalyzed oxidation of AS.
authors.affiliation: Max Planck Laboratory for Structural Biology, Chemistry and Molecular Biophysics of Rosario (MPLbioR), Universidad Nacional de Rosario, 27 de Febrero 210 bis, S2002LRK Rosario, Argentina; Instituto de Biología Molecular y Celular de Rosario, IBR-CONICET, Universidad Nacional de Rosario, 27 de Febrero 210 bis, S2002LRK Rosario, Argentina.
authors.forename: Marco C
authors.initials: MC
authors.lastname: Miotto
authors.affiliation: Department of NMR-supported Structural Biology, Leibniz Institute of Molecular Pharmacology (FMP), Robert-Roessle-Str. 10, 13125 Berlin, Germany.
authors.forename: Andrés
authors.initials: A
authors.lastname: Binolfi
authors.affiliation: Department of NMR-based Structural Biology, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, D-37077 Göttingen, Germany; German Center for Neurodegenerative Diseases (DZNE), 37077 Göttingen, Germany; Center for Nanoscale Microscopy and Molecular Physiology of the Brain (CNMPB), University Medicine Göttingen, 37073 Göttingen, Germany.
authors.forename: Markus
authors.initials: M
authors.lastname: Zweckstetter
authors.affiliation: Department of NMR-based Structural Biology, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, D-37077 Göttingen, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Griesinger
authors.affiliation: Max Planck Laboratory for Structural Biology, Chemistry and Molecular Biophysics of Rosario (MPLbioR), Universidad Nacional de Rosario, 27 de Febrero 210 bis, S2002LRK Rosario, Argentina; Instituto de Biología Molecular y Celular de Rosario, IBR-CONICET, Universidad Nacional de Rosario, 27 de Febrero 210 bis, S2002LRK Rosario, Argentina. Electronic address: cfernan@gwdg.de.
authors.forename: Claudio O
authors.initials: CO
authors.lastname: Fernández
mesh_terms: D000595:Amino Acid Sequence; D001665:Binding Sites; D002414:Cations, Monovalent; D003300:Copper / Q000737:chemistry*; D006639:Histidine / Q000737:chemistry*; D006801:Humans; D007700:Kinetics; D008969:Molecular Sequence Data; D010084:Oxidation-Reduction; D011485:Protein Binding; D054730:Protein Interaction Domains and Motifs; D017433:Protein Structure, Secondary; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics; D012996:Solutions; D013816:Thermodynamics; D051844:alpha-Synuclein / Q000737:chemistry* / Q000235:genetics
chemical_list: D002414:Cations, Monovalent; D011994:Recombinant Proteins; D012996:Solutions; D051844:alpha-Synuclein; D006639:Histidine; D003300:Copper
keywords: Alpha-synuclein; Cu(I); Met-rich sites; Parkinson