NR ATRS
AU Panza,G.; Dumpitak,C.; Stöhr,J.; Birkmann,E.; Riesner,D.
TI In vitro studies on the influence of polysaccharides and ageing-related protein modifications on aggregation and fibrillization of PrP
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-34
PT Konferenz-Poster
AB
Recently, the prion theory was proven by in vitro generation of synthetic prions from PrP only (1). However, the molecular mechanism of prion formation is not fully understood and synthetic prions lead only to small titers of infectivity. To understand those processes in more detail, knowledge about the influence of secondary components onto prion formation is essential. As such a secondary component of prions a polysaccharide scaffold was found amounting to ~ 10% (w/w) of highly purified prion rods. Analyses revealed that it consists predominantly 1,4-linked glucose with few 1,4,6-brances. The stereochemistry of the scaffold's glycosidic linkages was determined as predominantly, if not entirely alpha glycosidic, pointing to a close relationship to glycogen (2, 3).
The influence of such a polysaccharide onto the conformational transition of PrP was studied, applying an in vitro transition system, in which PrP was kept soluble at low concentrations of sodiumdodecylsulfate (SDS) and undergoes conformational transition with aggregation after dilution of SDS (4) or fibrillization in the presence of sodium chloride (5). Conformational transition, aggregation and fibrillization of rec PrP was examined in vitro using circular dichroism spectroscopy, confocal laser scanning microscopy, Thioflavin-T-fluorescence and electron microscopy.
Furthermore the question was addressed if ageing-associated advanced glycation endproducts (AGEs) could participate in prion pathogenesis. Therefore we studied the influence of AGEing on molecular properties and aggregation of PrP in vitro.
(1) Legname G, et al. (2004). Science 305: 673-676.
(2) Appel TR, et al. (1999). Biol. Chem. 380: 1295-1306.
(3) Dumpitak C, et al. (2005), Biol. Chem., in press.
(4) Post K., et al. (1998). Biol. Chem. 379: 1307-1317
(5) Leffers K-W, et al. (2005) Biol. Chem.386: 569-580.
AD G.Panza, C.Dumpitak, J.Stöhr, E.Birkmann, D.Riesner, Institut für Physikalische Biologie and Bioloisch-Medizinisches-Forschungszentrum, Heinrich-Heine-Universität, D-40225 Düsseldorf, Germany
SP englisch
PO Deutschland