NR AGUE
AU Kramer,M.L.; Kratzin,H.D.; Schmidt,B.; Römer,A.; Windl,O.; Liemann,S.; Hornemann,S.; Kretzschmar,H.A.
TI Prion protein binds copper within the physiological concentration range
QU The Journal of Biological Chemistry 2001 May 18; 276(20): 16711-9
PT journal article
AB The prion protein is known to be a copper-binding protein, but affinity and stoichiometry data for the full-length protein at a physiological pH of 7 were lacking. Furthermore, it was unknown whether only the highly flexible N-terminal segment with its octarepeat region is involved in copper binding or whether the structured C-terminal domain is also involved. Therefore we systematically investigated the stoichiometry and affinity of copper binding to full-length prion protein PrP(23-231) and to different N- and C-terminal fragments using electrospray ionization mass spectrometry and fluorescence spectroscopy. Our data indicate that the unstructured N-terminal segment is the cooperative copper-binding domain of the prion protein. The prion protein binds up to five copper(II) ions with half-maximal binding at approximately 2 microm. This argues strongly for a direct role of the prion protein in copper metabolism, since it is almost saturated at about 5 microm, and the exchangeable copper pool concentration in blood is about 8 microm.
MH Animal; Binding Sites; Copper/*metabolism; Human; Hydrogen-Ion Concentration; Kinetics; Mice; Peptide Fragments/chemical synthesis/chemistry/*metabolism; Prions/*chemistry/*metabolism; Protein Conformation; Spectrometry, Fluorescence; Spectrometry, Mass, Electrospray Ionization; Support, Non-U.S. Gov't
AD Department of Neuropathology, Georg August University of Göttingen, Robert-Koch-Strasse 40, 37075 Göttingen, Germany. mkramer@med.uni-goettingen.de
SP englisch
PO USA