Figure 2.

(a) Schematic representation of the spectrum of PrP^res fragments observed in animal prion diseases and their electrophoretic profile. The unglycosylated forms of all PrP^res fragments with the glycosylation sites in their sequence are indicated in orange, while the fragments lacking these sites are shown in red. Among the glycosylated peptides, only the mono- and the diglycosylated forms of PrP^res 27–30 (18–21 kDa range) fragments are shown (in blue). To facilitate the comparison with human forms, the profile of MM1 sCJD associated PrP^res is shown; note that the unglycosylated band of sCJDMM1 PrP^res has the same electrophoretic mobility of that of CWD as reported by Xie et al. [14]. (b) Diagrams of the secondary structural elements of sheep PrP^C and of the PK-resistant PrP fragments observed in classical and atypical Nor98 scrapie. Arrows are representative of β-strands and rectangles of α-helices and OR indicates the octapeptide repeats region. The secondary structure numbering has been derived from pdb (Protein Data Bank) id 1XYU (sheep PrP).