NR ATQV
AU Kupfer,L.; Proft,J.; Eiden,M.; Buschmann,A.; Groschup,M.H.
TI Conversion of cellular prion protein in a cell-free assay: The influence of amino acid substitutions with regard to the convertibility of the prion protein
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-11
PT Konferenz-Poster
AB
The crucial event in the pathogenesis of prion diseases or transmissible spongiform encephalopathies (TSEs) is an induced conformational change of cellular PrPc into an abnormal form which is designated PrPsc. This process is also called conversion and leads to modified biochemical properties of abnormal prion protein such as a partial resistance to proteinase K, aggregation and subsequent fibril formation.
However, the molecular mechanism underlying this structural transition remains unknown.
In a cell-free assay the conversion reaction can be mimicked by incubating highly purified recombinant PrPc molecules together with PrPsc seeds in an appropriate conversion buffer. Under these conditions we can show, that PrPsc itself can induce the conversion of PrPc into a partially proteinase K resistant form designated PrPres. This newly converted PrPres can be selectively detected by an antibody that reacts to an epitope tag which is absent in the seed derived PrPsc. In our assay we use procaryotically expressed PrPc as a substrate and mouse passaged scrapie strains/isolates as seeds.
Experiments were carried out using chimerical constructs, which consisted either of murine and ovine PrPc or of murine and bovine PrPc.
The experimental data show that even single or few amino acid substitutions within the prion protein have a major effect on its conversion.
Interestingly, these results are generally in line with in-vivo data which were obtained in transgenic mice carrying the chimerical PrPcs.
AD Leila Kupfer, Juliane Proft, Martin Eiden, Anne Buschmann, Martin H. Groschup, Institute for Novel and Emerging Infectious Diseases at the Friedrich-Loeffler-Institute Federal Research Institute for Animal Health
SP englisch
PO Deutschland