NR AOYE
AU Riek,R.; Ritter,C.; Lührs,T.; Balguerie,A.; Dos Reis,S.; Saupe,S.
TI The conformational switches of prion proteins
QU International Conference - Prion diseases: from basic research to intervention concepts - TSE-Forum, 08.10.-10.10.2003, Gasteig, München - Poster session - BR-03
PT Konferenz-Poster
AB
The three dimensional structure of the prion protein pHET-s of Podospora anserina consists of a N-terminal domain containing 7 helices and a C-terminal flexible tail comprising residues 218-289. The flexible tail forms amyloid fibrils in vitro and allows upon fibril formation prion propagation in vivo. Preliminary quenched H/D exchange NMR measurements, congo red staining, EM, time-resolved CD measurements and MTT formazan assay indicate the preservation of the folded domain and a conformational change of the flexible tail into a protease K resistant beta-sheet-rich conformation. Mutagenesis studies show, that although the prion domain consists of amino acid residues 218-289 single amino acid replacements in both the flexible tail and the well-folded N-terminal domain are able to inhibit prion propagation. In conclusion, all known prion proteins contain as a structural consensus motif a well-folded domain and a N- or C-terminal flexible tail, which is associated with infectivity. (Familial) mutations in the well-folded domains are able to influence the prion propagation.
In parallel, we established a protocol for the conformational transition of the mouse prion protein from an alpha-helical fold to a beta-sheet-rich dimer located in a membrane mimicking environment. This dimer has the competence to form amyloid fibrils that contain all the biophysical characteristics of the disease-associated scrapie form. Furthermore, expression and purification of glycosylated and/or GPI-anchored mouse prion protein in P. pastoris is established and the effects of these posttransitional modifications onto the three-dimensional structure and the conformational transition (using the established in vitro conversion protocol) will be discussed.
AD Roland Riek, Christiane Ritter, Thorsten Luhrs, The Salk Institute, USA; Axelle Balguerie, Suzana Dos Reis, Sven Saupe, Laboratoire de Genetique Moleculaire des Champignons CNRS/ Universite de Bordeaux, France
SP englisch
PO Deutschland