NR ATQM
AU Heindl,P.; Pfaff,E.; Tauscher,B.
TI Inactivation of transmissible spongiform encephalopathy agents by ultra high pressure treatment
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-02
PT Konferenz-Poster
AB
Suitable inactivation procedures for prions are aggressive, with a consequent loss in quality and texture in the treated tissues. Therefore, our interest in assessing the effects of unconventional milder technologies on prion stability and prion infectivity arises from the necessity of providing alternative sterilisation procedures for risk materials. High hydrostatic pressure is such a mild technology compared with high temperatures and is commonly used for food pasteurisation.
Crude brain homogenates of terminally diseased hamsters infected with the 263K strain of scrapie and isolated prion rods were heated and/or pressurised from 100 to 1000 MPa at 20 to 80 C for different holding times in different buffers and in water. Prion proteins were analysed on immunoblots for their proteinase K (PK) resistance, and in hamster bioassays for their infectivity. Samples pressurised at initial neutral conditions and containing native PrPsc or the N-truncated PrP 27-30 were negative on immunoblots [1,2], a 6-7 log reduction of infectious units per gram was reported in PBS buffer after a two hours treatment [2,3]. The notable decrease in the PK resistance and infectivity, probably because of pressure-induced changes in the protein conformation of native PrPsc or the N-truncated PrP27-30, could be demonstrated when pressurised at initially neutral conditions in several buffers and in water but not in slightly acidic pH [2,3]. In the case of slightly acidic buffers an extensive fraction of native PrPsc remained PK resistant after pressure treatment. Similarly results were found after pressurising isolated prions at neutral conditions [2], arguing for the existence of pressure sensitive and extremely pressure resistant beta-structures of the prion protein.
References:
[1] J Gen Vir, 2004, 85, 261-264.
[2] J Biol Chem, 2005, 280, 98.
[3] Braz J Med Biol Res, in press.
AD P.Heindl, B.Tauscher, Federal Research Centre for Nutrition and Food, Germany; E Pfaff, Federal Research Institute for Animal Health, Germany
SP englisch
PO Deutschland