NR AVOP
AU Eiden,M.; Palm,G.J.; Hinrichs,W.; Matthey,U.; Zahn,R.; Groschup,M.H.
TI Synergistic and strain-specific effects of bovine spongiform encephalopathy and scrapie prions in the cell-free conversion of recombinant prion protein
QU Journal of General Virology 2006 Dec; 87(12): 3753-61
PT journal article; research support, non-u.s. gov't
AB This study describes the conversion of murine PrPc by PrPsc from three different mouse scrapie strains (ME7, 87V and 22A) and from a mouse-passaged bovine spongiform encephalopathy (BSE) strain (BSE/Bl6). This was demonstrated by a modified, non-radioactive, cell-free conversion assay using bacterial prion protein, which was converted into a proteinase K (PK)-resistant fragment designated PrPres. Using this assay, newly formed PrPres could be detected by an antibody that discriminated de novo PrPres and the original PrPsc seed. The results suggested that PrPres formation occurs in three phases: the first 48 h when PrPres formation is delayed, followed by a period of substantially accelerated PrPres formation and a plateau phase when a maximum concentration of PrPres is reached after 72 h. The conversion of prokaryotically expressed PrPc by ME7 and BSE prions led to unglycosylated, PK-digested, abnormal PrPres fragments, which differed in molecular mass by 1 kDa. Therefore, prion strain phenotypes were retained in the cell-free conversion, even when recombinant PrPc was used as the substrate. Moreover, co-incubation of ME7 and BSE prions resulted in equal amounts of both ME7- and BSE-derived PrPres fragments (as distinguished by their different molecular sizes) and also in a significantly increased total amount of de novo-generated PrPres. This was found to be more than twice the amount of either strain when incubated separately. This result indicates a synergistic effect of both strains during cell-free conversion. It is not yet known whether such a cooperative action between BSE and scrapie prions also occurs in vivo.
MH Animals; Cattle; Cell-Free System; Electrophoresis, Polyacrylamide Gel; Endopeptidase K/metabolism; Immunoblotting; Kinetics; Mice; Molecular Weight; PrPc Proteins/*chemistry/metabolism; PrPsc Proteins/*chemistry/metabolism; Recombinant Proteins/chemistry
AD Institute for Novel and Emerging Infectious Diseases at the Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Boddenblick 5a, 17493 Greifswald-Insel Riems, Germany.
SP englisch
PO England