title: The configuration of the Cu2+ binding region in full-length human prion protein.
abstract: The cellular prion protein (PrP(C)) is a Cu(2+) binding protein connected to the outer cell membrane. The molecular features of the Cu(2+) binding sites have been investigated and characterized by spectroscopic experiments on PrP(C)-derived peptides and the recombinant human full-length PrP(C )(hPrP-[23-231]). The hPrP-[23-231] was loaded with (63)Cu under slightly acidic (pH 6.0) or neutral conditions. The PrP(C)/Cu(2+)-complexes were investigated by extended X-ray absorption fine structure (EXAFS), electron paramagnetic resonance (EPR), and electron nuclear double resonance (ENDOR). For comparison, peptides from the copper-binding octarepeat domain were investigated in different environments. Molecular mechanics computations were used to select sterically possible peptide/Cu(2+) structures. The simulated EPR, ENDOR, and EXAFS spectra of these structures were compared with our experimental data. For a stoichiometry of two octarepeats per copper the resulting model has a square planar four nitrogen Cu(2+) coordination. Two nitrogens belong to imidazole rings of histidine residues. Further ligands are two deprotonated backbone amide nitrogens of the adjacent glycine residues and an axial oxygen of a water molecule. Our complex model differs significantly from those previously obtained for shorter peptides. Sequence context, buffer conditions and stoichiometry of copper show marked influence on the configuration of copper binding to PrP(C).
authors.affiliation: Physics Department E17, Technical University Munich, 85747 Garching, Germany.
authors.forename: Pablo
authors.initials: P
authors.lastname: del Pino
authors.forename: Andreas
authors.initials: A
authors.lastname: Weiss
authors.forename: Uwe
authors.initials: U
authors.lastname: Bertsch
authors.forename: Christian
authors.initials: C
authors.lastname: Renner
authors.forename: Matthias
authors.initials: M
authors.lastname: Mentler
authors.forename: Klaus
authors.initials: K
authors.lastname: Grantner
authors.forename: Ferdinando
authors.initials: F
authors.lastname: Fiorino
authors.forename: Wolfram
authors.initials: W
authors.lastname: Meyer-Klaucke
authors.forename: Luis
authors.initials: L
authors.lastname: Moroder
authors.forename: Hans A
authors.initials: HA
authors.lastname: Kretzschmar
authors.forename: Fritz G
authors.initials: FG
authors.lastname: Parak
mesh_terms: D001665:Binding Sites; D003198:Computer Simulation; D003300:Copper / Q000737:chemistry*; D006801:Humans; D008956:Models, Chemical; D008958:Models, Molecular; D018621:PrPC Proteins / Q000737:chemistry* / Q000648:ultrastructure*; D011485:Protein Binding; D011487:Protein Conformation; D017434:Protein Structure, Tertiary
chemical_list: D018621:PrPC Proteins; D003300:Copper