Detergents modify proteinase K resistance of PrPSc in different transmissible spongiform encephalopathies (TSEs)

Abstract

Prion diseases are diagnosed by the detection of their proteinase K-resistant prion protein fragment (PrPSc). Various biochemical protocols use different detergents for the tissue preparation. We found that the resistance of PrPSc against proteinase K may vary strongly with the detergent used. In our study, we investigated the influence of the most commonly used detergents on eight different TSE agents derived from different species and distinct prion disease forms. For a high throughput we used a membrane adsorbtion assay to detect small amounts of prion aggregates, as well as Western blotting. Tissue lysates were prepared using DOC, SLS, SDS or Triton X-100 in different concentrations and these were digested with various amounts of proteinase K. Detergents are able to enhance or diminish the detectability of PrPSc after proteinase K digestion. Depending on the kind of detergent, its concentration - but also on the host species that developed the TSE and the disease form or prion type - the detectability of PrPSc can be very different. The results obtained here may be helpful during the development or improvement of a PrPSc detection method and they point towards a detergent effect that can be additionally used for decontamination purposes. A plausible explanation for the detergent effects described in this article could be an interaction with the lipids associated with PrPSc that may stabilize the aggregates.

Polythiophenes Inhibit Prion Propagation by Stabilizing Prion Protein (PrP) Aggregates

“…PTAA also caused a left shift in the conformational stability curve of PrP Sc after exposure to increasing concentrations of the nonsurfactant-type chaotrope, GdnHCl. This concentration-dependent behavior of the LCPs resembles the mechanisms reported for several surfactants that were assumed to affect protein aggregation in a two-concentration regime by either interacting as single molecules or in equilibrium with small molecule aggregates (52) and were demonstrated to enhance or reduce the stability and detectability of PK-resistant PrP Sc (18,53,54). The concentration-dependent interaction of surfactants with aggregated proteins may induce conformational versatility.…”

Can plants serve as a vector for prions causing chronic wasting disease?

“…The high concentration of detergents in the extraction buffer affected the PK-resistance of prions, as other studies have confirmed. 22 A 1% SDS solution was used as an alternate extraction procedure to preserve PK-resistance of PrP TSE based on other studies that extracted PrP TSE from compost (Fig. 4).…”

Stability properties of PrPScfrom cattle with experimental transmissible spongiform encephalopathies: use of a rapid whole homogenate, protease-free assay

“…Namely, the use of detergent to probe the structural stability of PrP Sc revealed that classical BSE was more resistant to detergent treatment (as probed over a range of detergent types) than was German L-type BSE [41]. As noted by Breyer et al [41], the detergent treatment affects protein stability through hydrophilic and hydrophobic interactions, as compared to the effect of GdnHCl which may influence hydrogen bonding. Proteinase K treatment was used subsequent to detergent treatment, similar to the use of PK after GdnHCl treatment in some other forms of the stability assay.…”

“…We suggest that further comparison of the results of these different assays will provide us with more information about the differences in prion structure and aggregation patterns that cause the strain-dependent differences. The effect of the lipid component of PrP Sc aggregates [41] is of particular interest, and further studies with the rapid stability assay will consider the impact of detergent treatment and lipid extraction on stability of isolates in GdnHCl.…”