NR AXVV
AU Salwierz,A.; Elfrink,K.; Müller-Schiffmann,A.; Korth,C.; Riesner,D.
TI Influence of the Cellular Membrane on Prion Protein Infection Mechanism
QU International Conference - Prion 2007 (26.-28.9.2007) Edinburgh International Conference Centre, Edinburgh, Scotland, UK - Book of Abstracts: Protein Misfolding P01.57
IA http://www.prion2007.com/pdf/Prion Book of Abstracts.pdf
PT Konferenz-Poster
AB
The conversion of the cellular isoform of the prion protein (PrPc) into the diseaseassociated PrPsc plays a crucial role in development of prion diseases. Within its cellular pathway PrPc undergoes several posttranslational modifications, i.e. attachment of two N-linked glycans and a glycosyl phosphatidyl inositol (GPI-) anchor to its C-terminus. With help of this anchor prion protein is linked to special membrane domains on the exterior cell surface, called rafts. There are several hints leading to a hypothesis, that the conversion process might take place either at the membrane surface or in its close proximity (1, 2). In order to study the influence of the membrane environment on the structural transition process we purified posttranslationally modified PrPc from transgenic CHO-cells (3, 4). The purification method consists of two chromatographic steps namely: the copper immobilized metal-chelate affinity chromatography that is followed by a highly specific immunopurification step, where different monoclonal and recombinant antibodies were tested. The purified, soluble CHO-PrPc was then inserted into model membranes bound on a chip surface and the thermodynamics and kinetics of the insertion were analyzed quantitatively (5). Next we studied the interaction with an exogenously added second component i.e. PrPaggregates in ß-sheet rich structure. These experiments were performed using a Biacore device, which utilizes the surface plasmon resonance (SPR) technique. We could observe a different behavior of the aggregated protein depending on the presence of PrPc anchored in the lipid bilayer. These differences were significant and showed no or little binding when the aggregated PrP-particles were injected over an empty lipid bilayer in comparison with a very strong, disrupting effect on the membrane-bound PrPc.
(1) Kaneko, K.et al. (1997) Proc. Nat. Acad. Sci. 94, 2333-2338
(2) Baron, G. S., Caughey, B. (2003) J. Biol. Chem. 278, 14883-14892
(3) Blochberger, T.C. et al. (1997) Prot. Eng. 10, 1465-1473
(4) Elfrink, K., Riesner, D. (2004) ed. by S. Lehmann and J. Grassi (Birkhaeuser Verlag Basel), 4-15
(5) Elfrink K. et al. (2007) Biol. Chem. 388, 79-89
AD A. Salwierz, D. Riesner, Heinrich-Heine University, Institut für Physikalische Biologie, Germany; K. Elfrink, Westfälische Wilhelms University, Institut für allgemeine Zoologie und Genetik, Germany; A. Müller-Schiffmann, C. Korth, Heinrich-Heine University, Institut für Neuropathologie, Germany
SP englisch
PO Schottland