Prions, proteinase K and infectivity

Targeting prion propagation using peptide constructs with signal sequence motifs

“…Prion strains RML and 22L differ in infectivity in cell lines and trigger various changes in gene expression and pathological hallmarks in infected mice [46]. Here, proteinase K (PK)-resistance was used as a diagnostic of formation of the Scrapie form of PrP [4,5]. Western blots were used to detect total PrP-levels (PrP Tot ) in cell extracts (Fig.…”

“…The so called Scrapie isoform of the prion protein (PrP Sc , in infectious prions), probably in an oligomeric form [3], is a biological and medical concept associated with infection and disease. Here we will generally use the term PrP Res , chemically defined as the isoform of PrP which is resistant to proteinase K, a characteristic closely but not entirely linked to prion infectivity [4,5].…”

Comparison of conventional, amplification and bio-assay detection methods for a chronic wasting disease inoculum pool

“…The major challenge to early diagnosis of prion diseases has been the very low prion concentrations and/or inhibitors that are present in accessible biological samples [19–21]. In addition, prion infectivity is comprised of variably protease sensitive particles [22], yet conventional prion detection methods require the use of protease digestion, which ablates sensitive forms of prion infectivity (PrP Sen ) and reduces sensitivity. Thus, while bioassay in native and transgenic hosts remains the gold standard for assessment of prion infectivity in biological samples, it remains burdensome due to animals, time required and cost.…”

The Extent of Protease Resistance of Misfolded Prion Protein Is Highly Dependent on the Salt Concentration

“…Alternative approaches have therefore relied on low-resolution techniques such as transmission electron microscopy and atomic force microscopy (4,13). Size fractionation and protease-based assays have also complemented the biochemical analysis of PrP Sc (14). These approaches have also been critical for the characterization of different prion strains, which are thought to be different PrP conformers that emerge from the same primary sequence (15).…”

“…Brain-derived and recombinant PrP Sc are known to withstand high concentrations of protease treatment (14,16). The protease-resistant subpopulation of PrP Sc (PrPres) encompasses a C-terminal PrP fragment starting at around residue 90, with the exact position depending upon the prion strain.…”