NR AXLE
AU Drew,S.C.; Han,S.; Curtain,C.C.; Cappai,R.; Hill,A.F.; Barnham,K.J.
TI Copper Binding and Redox Activity of the Infectious Isoform of the Prion Protein Monitored by Fluorescence and EPR Apectroscopy
QU International Conference - Prion 2007 (26.-28.9.2007) Edinburgh International Conference Centre, Edinburgh, Scotland, UK - Book of Abstracts: Pathology and Pathogenesis P03.42
IA http://www.prion2007.com/pdf/Prion Book of Abstracts.pdf
PT Konferenz-Poster
AB
The structure of the infectious agent responsible for prion diseases has not been fully characterized, but evidence points to a ß-rich conformer of the host-encoded prion protein. It undergoes a structural transition that has been associated with a gain of toxic function, inducing neuronal oxidative stress via production of free adicals. In particular, tyrosyl radical formation has been suggested to play a part in the redox cycle that leads to hydrogen peroxide production of copper-bound PrP [1]. Such radicals are usually only transiently stable and rapidly decay. The technique of spin trapping involves the formation of radical adducts which are more stable than the primary free radical and the identity of the trapped radical can be characterized by EPR spectroscopy. Our preliminary EPR spin trapping studies suggested the generation of carbon-centered radicals in full-length and C-terminal fragments of the a and ßisoforms of recombinant moPrP. We have further used fluorogenic spin traps, whose fluorescence is altered upon trapping a radical, to enable a large number of mutant constructs to be analysed under a range of pH, buffer and copper loading conditions in a highl-throughput assay. We have examined a variety of full length and truncated PrP constructs containing various single and double mutations to identify differences between the a and ß conformers as a function of both pH and copper loading.
[1] Barnham KJ, Cappai R, Beyreuther K, Masters CL, Hill AF, Delineating common molecular mechanisms in Alzheimer's and prion diseases, TRENDS in Biochem. Sci. 2006; 31: 465-472.
AD S.C. Drew, C.C. Curtain, R. Cappai, K.J. Barnham, The University of Melbourne, Department of Pathology, Australia; S. Han, A.F. Hill, The University of Melbourne, Department of Biochemistry & Molecular Biology, Australia
SP englisch
PO Schottland