NR AXQU
AU Langeveld,J.; Groschup,M.H.; Buschmann,A.; Becher,D.; Wang,J.J.; Shih,J.C.H.
TI Enzymatic Degradation of PrPsc Fails to Dis-Infect Bovine BSE Brain Homogenates
QU International Conference - Prion 2007 (26.-28.9.2007) Edinburgh International Conference Centre, Edinburgh, Scotland, UK - Book of Abstracts: Oral Abstracts FC7.2
IA http://www.prion2007.com/pdf/Prion Book of Abstracts.pdf
PT Konferenz-Vortrag
AB
Prions are considered to be dependent on their protein component for infectivity. A previous study with keratinase demonstrated degradation of PrPsc from infected bovine and ovine brain stem homogenates after a unique heat pretreatment procedure. This discovery offered the possibility of a mild option for removal of prion infectivity (Langeveld et al., 2003, J. Infect. Dis., 188:1782-1789). Using these methods, the level of infectivity reduction of bovine prions was tested in transgenic Tgbov XV mice that are susceptible for bovine BSE over a range of 7 orders of magnitude. To assure the degradation of PrPsc different antibodies with specific epitopes distributed over bovine PrP such as SAF32, 12B2, 9A2, 6H4, 94B4, and F99/97.6.1 were used for detection after SDS-PAGE and Western blotting. The infectivity of the untreated inoculum reached values above 106.5 ID50/g tissue in Tgbov XV mice. After heat pre-treatment of
bovine brain stem homogenate and subsequent digestion with keratinase, PrP on Western blots was completely undetectable with any of the PrP specific antibodies, while components in the range above 200 kDa and below 7 kDa were present at strongly reduced levels in SDS PAGE gels stained with Coomassie brilliant blue or silver, indicating that the enzymatic process for protein degradation was highly effective. Unexpectedly infectivity was fully preserved after the enzymatic digestion when tested in the mice. These results point out the presence of a non-infectious, heat resistant, but protease sensitive fraction which represents the overwhelming bulk of the abnormal PrPsc. In comparison, infectious PrPsc if still present, is even more resistant to protease treatment than thought before and will represent only a minute immunochemically undetectable entity. Studies on these infectious fractions may provide new insights into the true nature of prions.
Acknowledgements: This study was supported mainly by the National Cattleman and Beef Association of USA and further by German and Dutch Ministries for Agriculture as well as the EU FP6 framework FOOD-CT-2004-506579 NeuroPrion project "PRIONINACT".
AD J. Langeveld, CIDC-Lelystad, Department of Bacteriology and TSEs, Netherlands; M.H. Groschup, A. Buschmann, FriedrichLöffler-Institut (FLI-INEID), Institute for Novel and Emerging Diseases, Germany; D. Becher, Micromun GmbH, Germany; J.J. Wang, BioResource International, USA; J.C.H. Shih, North Carolina State University, USA
SP englisch
PO Schottland