Protein conformation determines the sensibility to high pressure treatment of infectious scrapie prions

High-Pressure Chemical Biology and Biotechnology

“…Many authors have evaluated the effects of high pressure on TSE-contaminated samples from tissue or processed meat. The combination of high pressure (500–1200 MPa) and temperature (milder temperatures that do not affect food quality, of up to 137 °C) was shown to decrease infectivity, but the obtained efficiency was dependent on the conditions applied and the material treated. − ,, The resultant inactivation of prion biological activity was shown to be irreversible, and although it was not complete, the remaining infective units would be very few and most likely would be insufficient for oral infection …”

“…High pressure reduces the proteinase resistance and infectivity of PrP Sc when applied at temperatures of approximately 60 °C, with a reduction of infectivity to 6−7 log infectious units/g being observed. 188 On the other hand, purified PrP Sc is resistant to this treatment. 174,188 It is believed that centrifugation steps performed during purification lead to the formation of resistant highly aggregated species with fewer packing defects, as has been observed for late temperatureinduced aggregates 170 and fibrils following pressure treatment.…”

“…188 On the other hand, purified PrP Sc is resistant to this treatment. 174,188 It is believed that centrifugation steps performed during purification lead to the formation of resistant highly aggregated species with fewer packing defects, as has been observed for late temperatureinduced aggregates 170 and fibrils following pressure treatment. 184 However, an alternative explanation is that these two scrapie conformations can coexist.…”

High pressure/temperature treatments to inactivate highly infectious prion subpopulations

“…Previous works have shown a strong reduction in the infectivity of scrapie prions as a function of pressure and heat (Fernandez Garcia et al, 2004;Heindl et al, 2005;Heindl, Fernandez Garcia, Butz, Pfaff & Tauscher, 2006) also associated to a decrease on the PK resistant fraction detected on immunoblots. Here the kinetic parameters governing the pressure inactivation of the 263K strain of scrapie were studied.…”

In vivo prion protein intestinal uptake in fish

“…Nevertheless, although exposure to PrP Sc should not most likely cause any clinical signs in fish, the pathological agent could persist in tissues, and the risk of prion propagation should be taken into account (32). In addition, prion disorder agents are relatively resistant to a wide variety of food processing procedures (33). In other words, after eating PrP Sc , fish might be a reservoir of the potentially infectious agent, even if not suffering from any disease.…”