NR ATRK
AU Redecke,L.; von Bergen,M.; Meyer-Klaucke,W.; Svergun,D.I.; Clos,J.; Georgieva,D.; Genov,N.; Betzel,C.
TI Structural Investigation of Human Prion Protein Aggregation Induced by Metal-Catalyzed Oxidation
QU International Conference - Prion 2005: Between fundamentals and society's needs - 19.10.-21.10.2005, Congress Center Düsseldorf - Poster Session: Structure of PrP and molecular determinants of infectivity STRCT-26
PT Konferenz-Poster
AB
The posttranslational conversion of the prion protein from its normal cellular isoform (PrPc) into its misfolded infectious state (PrPsc) is considered to act as a key event during the course of prion diseases. However, the physiological functions of the cellular prion protein as well as the pathogenesis of neuronal cell death in prion diseases remain still enigmatic. In addition to several other mechanisms, oxidative stress has been proposed to be a pivotal event in the pathology of prion disease, similarly to its role in other neurodegenerative disorders. Furthermore, increasing evidence supports the hypothesis that soluble oligomers are potentially responsible for neuronal pathologies associated with protein misfolding and aggregation.
In this context, we comparatively investigated the structural alterations of recombinant human PrP (90-231) induced by metal-catalyzed oxidation as well as by elevated temperatures. The required redox-system was established by incubating elemental metals (Cu0, Fe0 and Zn0) in slightly acidic solution (pH 5). Oxidation of PrP is accompanied by fundamental conformational changes resulting in extensive aggregation of highly beta-sheeted PrP-isoforms, whereas heat-induced oligomerization occurs only marginally without affecting the secondary structure content. We show for the first time that well-defined soluble oligomers of elongated shape are formed in the pathway of oxidative PrP aggregation, which are characterized by an assembly of approx. 20 PrP molecules using small-angle X-ray scattering (SAXS) methods. Moreover, extended X-ray absorption fine structure (EXAFS) measurements revealed that the generated high molecular mass aggregates coordinate Cu2+ in a specific geometry indicating a structural influence of the metal ions during aggregate formation. Consequently, metal-catalyzed oxidation of PrP represents a promising model system to generate oligomers and aggregates suitable for further cellular investigations.
AD Lars Redecke, University Hospital Hamburg-Eppendorf, Germany; Martin von Bergen, Max-Planck Unit for Structural Molecular Biology, Germany; Wolfram Meyer-Klaucke, Dimitri Svergun, EMBL Outstation Hamburg, Germany; Joachim Clos, Bernhard-Nocht-Institute for Tropical Medicine, Germany; Dessislava Georgieva, Christian Betzel, University of Hamburg, Germany; Nicolay Genov, Bulgarian Academy of Sciences, Bulgaria
SP englisch
PO Deutschland