NR AWEH
AU Dumpitak,C.; Panza,G.; Stöhr,J.; Birkmann,E.; Riesner,D.
TI Accelerated aggregation and fibrillization of the prion protein in presence of glycogen
QU International Conference - Prion 2006: Strategies, advances and trends towards protection of society - 3.10.-6.10.2006, Torino, Italy, Lingotto Conference Centre - Poster sessions S-08
PT Konferenz-Poster
AB Natural prions are mainly composed of aggregated and misfolded prion protein (PrP). They are highly infective and normally display high stability against degradation. Although the prion theory was proven by in vitro generation of synthetic prions from recombinant PrP only (1, 2), the molecular details of prion formation are not yet fully understood, especially since synthetic prions led only to small titers of infectivity. Therefore it is essential to understand PrP misfolding and aggregation in the context of known non-PrP components of natural occuring prions. Such a common secondary component of natural prions is the polysaccharide scaffold which in prion rods amounts up to 15 % (w/w). We showed that its structure consists of predominantly alpha-1,4-linked glucose with few 1,4,6-branches, indicating a close relationship with glycogen (3, 4). Alpha-1,4-linked glucose polysaccharides have unique structural properties as they can form complexes with hydrophobic molecules. Therefore we studied the influence of such a polysaccharide on the conformational transition of PrP, applying an in vitro conversion system, in which PrP is kept soluble at low concentrations of sodiumdodecylsulfate (SDS) and undergoes conformational transition with aggregation after dilution of SDS (5) or fribrillization in the presence of sodium chloride (6). Conformational transition, aggregation and fibrillization of recombinant PrP in the presence of glycogen was examined in vitro using circular dichroism spectroscopy, fluorescence correlation spectroscopy, confocal laser scanning microscopy, Thioflavin-T-fluorescence and electron microscopy. Here we report that glycogen supports and accelerates PrP amorphous aggregation comparable to seeded aggregation leading to coaggregates. Also formation of PrP fibrils was highly accelerated in the presence of glycogen. (1) Legname G, et al. (2004). Science 305: 673-676. (2) Legname G, et al. (2005). Proc. Natl. Acad. Sci. USA 102: 2168-2173. (3) Appel TR, et al. (1999). Biol. Chem. 380: 1295-1306. (4) Dumpitak C, et al. (2005), Biol. Chem. 386: 1149-1155. (5) Post K, et al. (1998). Biol. Chem. 379: 1307-1317 (6) Leffers K-W, et al. (2005) Biol. Chem.386: 569-580.
AD Institut für Physikalische Biologie and Biologisch-Medizinisches-Forschungszentrum, Heinrich-Heine-Universität, D-40225 Düsseldorf, Germany. E-mail: dumpitak@biophys.uni-duesseldorf.de
SP englisch
PO Italien