NR AWKU
AU Müller,H.; Stitz,L.; Riesner,D.
TI Prions and fats: protection or destruction?
QU International Conference - Prion 2006: Strategies, advances and trends towards protection of society - 3.10.-6.10.2006, Torino, Italy, Lingotto Conference Centre - Oral sessions ORAL-54
PT Konferenz-Vortrag
AB The inactivation of prion infectivity and the degradation of the PrP27-30 peptide backbone are influenced profoundly by solution conditions. The qualitative and quantitative comparison of degradation and inactivation of prion infectivity, both determined with the most stable form of the TSE agent, the so-called prion rods, demonstrated differences in the heat-mediated reduction of a factor up to 105. The presence of fat, fatty acids, and particularly glycerol has a profound capacity to protect the peptide backbone integrity of PrP27-30 against heat degradation. Whereas the protective effect of fat and fatty acid is lost with increasing temperature as compared to the heat degradation in water (1, 2), the protective effect of glycerol dominates over the degradation activity of water. Under all conditions analysed the inactivation of prion infectivity is achieved several orders of magnitude more efficiently than the degradation of the PrP peptide backbone occurs. Whereas inactivation in presence of fats is increased compared to pure water conditions, it is decreased in presence of glycerol. The inactivation in fat water mixtures exceeds that of the pure components. From our systematic analyses it can be concluded that the industrial conditions of the basic oleochemical process of hydrolytic fat splitting inactivate safely an unforeseen contamination from BSE-infected raw material and guarantee prion-free products (3). The distribution of prions between fat and water phases was analysed quantitatively. The phase distribution experiments indicated that PrP27-30 migrates to the fat water interphase. Only by increasing temperature, detergent concentration, or salt concentration a notable amount of PrP27-30 was obtained in the water phase. From the experimental data, a systematic interpretation of the mechanisms of prion inactivation and degradation and of the interactions contributing could be derived. An analysis of heat-induced structural changes of PrP27-30 as well as of a possible alteration of the PK resistance is underway. (1) Appel et al., J Gen Virol. 2001, 82, 465-473 (2) Müller & Riesner, Eur J Lipid Sci Technol. 2005, Nov 11, Vol. 107: 833-9 (3) Müller et al., Eur J Lip Sci Technol, submitted
AD H.Müller, D. Riesner: Institut für Physikalische Biologie, Heinrich - Heine - Universität Düsseldorf, Universitätsstraße 1, D-40225 Düsseldorf; L. Stitz: Friedrich Löffler-Institut (FLI), Bundesforschungsinstitut für Tiergesundheit, Paul Ehrlich-Straße 28, D-72076 Tübingen, Germany. E-mail: mueller@biophys.uni-duesseldorf.de
SP englisch
PO Italien