A protease-resistant protein is a structural component of the Scrapie prion

Abstract

Fractions purified from scrapie-infected hamster brain contain a unique protein, designated PrP. It was labeled with N-succinimidyl 3-(4-hydroxy-5-[125I]-iodophenyl) propionate, which did not alter the titer of the scrapie prion. The concentration of PrP was found to be directly proportional to the titer of the infectious prion. Both PrP and prion infectivity were resistant for 2 hr at 37 degrees C to hydrolysis by proteinase K under nondenaturing conditions. Prolonging the digestion resulted in a concomitant decrease in both PrP and the scrapie prion. When the amino-acid-specific proteases trypsin or SV-8 protease were used instead of proteinase K, no change in either PrP or the prion was detected. The parallel changes between PrP and the prion provide evidence that PrP is a structural component of the infectious prion. Our findings also suggest that the prion contains only one major protein, namely PrP.

Molecular biology of transmissible spongiform encephalopathies

“…As mentioned above, Pr0tease treatment of prion preparations cleaves off about 60 amino terminal residues of PrP sc [55] but does not abrogate infectivity [56]. We introduced into PrP knockout mice transgenes encoding wild-type PrP or PrP lacking 26 or 49 amino proximal amino acids which are protease-susceptible in prpS% Inoculation with prions led to fatal disease (Fig.…”

Western blot mapping of disease-specific amyloid in various animal species and humans with transmissible spongiform encephalopathies using a high-yield purification method

“…SAF consist primarily of the disease-specific SAFprotein [also referred to as protease-resistant protein or prion protein, PrP (Bolton et al, 1982;McKinley et al, 1983)] (Diringer et al, 1983a;Barry et al, 1985;DeArmond et al, 1985;Merz et al, 1987;Wiley et al, 1987). This amyloid protein is derived from a highly conserved host-encoded precursor, a cellular glycoprotein (tool.…”

Effect of Time and Temperature on PrPCWD Immunoreactivity as Evidenced by Western Blot

“…Tissue examination using assays based on other monoclonal antibodies and other formats (e.g., enzyme-linked immunosorbent assays) and could reveal such selective epitope loss. Although modifications to PrP Res have the potential to diminish prion titer, 6 infectivity has been established with scrapie samples that produce no signal on WB. 13 Ultimately, in order to determine if temperature-and time-dependent reduction of PrP CWD immunodetection correlates with prion degradation and reduced infectivity, kinetic bioassay studies are required.…”