NR AURP
AU Panza,G.; Dumpitak,C.; Stöhr,J.; Birkmann,E.; Riesner,D.
TI Aggregation and fibrillization of PrP in the presence of polysaccharides
QU TSE-Forum, 6. Kongress - Nationale TSE-Forschungsplattform, Greifswald 26.6.-28.6.2006, Poster: Struktur und molekulare Mechanismen MOL-13
PT Konferenz-Poster
AB
Although the prion theory was proven by in vitro generation of synthetic prions from pure recombinant PrP (1, 2), the details of the molecular mechanism of prion formation are not yet fully understood, especially since synthetic prions lead only to small titers of infectivity. In particular the role of secondary components found in natural occuring prions might be essential.
An inert glucose polysaccharide scaffold was identified as common, non-covalently bound component of prions amounting to ~ 10% (w/w) of prion rods. Chemical analyses revealed its structure consisting of predominantly alpha-1,4-linked glucose with few 1,4,6-brances, thus showing a high similarity to glycogen (3, 4).
Therefore the influence of such a polysaccharide onto the conformational transition of PrP was studied, applying an in vitro transition system, in which PrP is kept soluble at low concentrations of sodiumdodecylsulfate (SDS) and undergoes, after dilution of SDS, conformational transition either to amorphous aggregates (5) or, in the presence of sodium chloride, to amyloidic fibrils (6). Conformational transition, aggregation and fibrillization of recombinant PrP was examined in vitro using circular dichroism spectroscopy, Thioflavin-T-fluorescence, confocal laser scanning and electron microscopy. Substantially accelerated PrP aggregation and amyloid formation was observed in the presence of model polysaccharides similar to the prion scaffold.
(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 G.Panza, C.Dumpitak, J.Stöhr, E.Birkmann and D. Riesner, Institut für Physikalische Biologie and Biologisch-Medizinisches-Forschungszentrum, Heinrich-Heine-Universität, D-40225 Düsseldorf, Germany
SP englisch
PO Deutschland
OR Tagungsband