title: A novel copper(II) coordination at His186 in full-length murine prion protein.
abstract: To explore Cu(II) ion coordination by His(186) in the C-terminal domain of full-length prion protein (moPrP), we utilized the magnetic dipolar interaction between a paramagnetic metal, Cu(II) ion, and a spin probe introduced in the neighborhood of the postulated binding site by the spin labeling technique (SDSL technique). Six moPrP mutants, moPrP(D143C), moPrP(Y148C), moPrP(E151C), moPrP(Y156C), moPrP(T189C), and moPrP(Y156C,H186A), were reacted with a methane thiosulfonate spin probe and a nitroxide residue (R1) was created in the binding site of each one. Line broadening of the ESR spectra was induced in the presence of Cu(II) ions in moPrP(Y148R1), moPrP(Y151R1), moPrP(Y156R1), and moPrP(T189R1) but not moPrP(D143R1). This line broadening indicated the presence of electron-electron dipolar interaction between Cu(II) and the nitroxide spin probe, suggesting that each interspin distance was within 20 A. The interspin distance ranges between Cu(II) and the spin probes of moPrP(Y148R1), moPrP(Y151R1), moPrP(Y156R1), and moPrP(T189R1) were estimated to be 12.1 A, 18.1 A, 10.7 A, and 8.4 A, respectively. In moPrP(Y156R1,H186A), line broadening between Cu(II) and the spin probe was not observed. These results suggest that a novel Cu(II) binding site is involved in His186 in the Helix2 region of the C-terminal domain of moPrP(C).
authors.affiliation: Laboratory of Radiation Biology, Graduate School of Veterinary Medicine, Hokkaido University, Sapporo 060-0818, Japan.
authors.forename: Yasuko
authors.initials: Y
authors.lastname: Watanabe
authors.forename: Wakako
authors.initials: W
authors.lastname: Hiraoka
authors.forename: Manabu
authors.initials: M
authors.lastname: Igarashi
authors.forename: Kimihito
authors.initials: K
authors.lastname: Ito
authors.forename: Yuhei
authors.initials: Y
authors.lastname: Shimoyama
authors.forename: Motohiro
authors.initials: M
authors.lastname: Horiuchi
authors.forename: Tohru
authors.initials: T
authors.lastname: Yamamori
authors.forename: Hironobu
authors.initials: H
authors.lastname: Yasui
authors.forename: Mikinori
authors.initials: M
authors.lastname: Kuwabara
authors.forename: Fuyuhiko
authors.initials: F
authors.lastname: Inagaki
authors.forename: Osamu
authors.initials: O
authors.lastname: Inanami
mesh_terms: D000818:Animals; D003300:Copper / Q000378:metabolism*; D006639:Histidine / Q000235:genetics / Q000378:metabolism*; D057927:Hydrophobic and Hydrophilic Interactions; D051379:Mice; D018621:PrPC Proteins / Q000235:genetics / Q000378:metabolism*; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary
chemical_list: D018621:PrPC Proteins; D006639:Histidine; D003300:Copper