title: Copper(II) complexes with an avian prion N-terminal region and their potential SOD-like activity.
abstract: Potentiometric and spectroscopic (UV-Vis, CD and EPR) studies were carried out on copper(II) complexes with chicken prion protein N-terminal fragments, Ac-(PHNPGY)(4)-NH(2), and the mutated residue, Ac-(PHNPGF)(4)-NH(2), to assess the role of tyrosine in the copper coordination. Both thermodynamic and spectroscopic results indicate that chicken prion fragments are not able to bind more than two copper ions and only with the involvement of side chain tyrosine groups. The prevailing complex shows one copper ion bound to four imidazole nitrogen atoms in the 1:1 metal to ligand ratio systems. The superoxide dismutase (SOD)-like activity of copper(II) complexes with the avian peptides and mammal analogue, Ac-(PHGGGWGQ)(4)-NH(2), was also investigated by means of Pulse radiolysis. The copper(II) complexes with avian peptides do not display SOD-like activity, while very low activity has been detected for the copper(II) complexes with mammalian tetraoctarepeat.
authors.affiliation: Istituto di Biostrutture e Bioimmagini-CNR-Catania, Viale A. Doria 6, 95125 Catania, Italy.
authors.forename: Diego
authors.initials: D
authors.lastname: La Mendola
authors.forename: Raffaele P
authors.initials: RP
authors.lastname: Bonomo
authors.forename: Serena
authors.initials: S
authors.lastname: Caminati
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Di Natale
authors.forename: Salvatore S
authors.initials: SS
authors.lastname: Emmi
authors.forename: Orjan
authors.initials: O
authors.lastname: Hansson
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Maccarrone
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Pappalardo
authors.forename: Adriana
authors.initials: A
authors.lastname: Pietropaolo
authors.forename: Enrico
authors.initials: E
authors.lastname: Rizzarelli
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002645:Chickens; D003300:Copper / Q000737:chemistry*; D051379:Mice; D010446:Peptide Fragments / Q000138:chemical synthesis / Q000737:chemistry / Q000302:isolation & purification; D011328:Prions / Q000737:chemistry* / Q000235:genetics; D013057:Spectrum Analysis; D013482:Superoxide Dismutase / Q000737:chemistry*; D013816:Thermodynamics
chemical_list: D010446:Peptide Fragments; D011328:Prions; D003300:Copper; D013482:Superoxide Dismutase