- PrP^sc is an isoform which has less alpha helix and more beta-pleated sheet than PrP^c, it is more proteinase-k-resistant than PrP^c.
- PrP^sc, but not PrP^c, self-aggregates into fibrils which appear as rods of amyloid in infected brains.
- PrP^sc has two more glycosylation sites whereas as Pr^c and PrP from spontaneous CJD have only one. It therefore igrates at 27-30KD compared to 21KD.
- The glycosylation sites are involved in the self aggregation of PrP^sc.
- PrP^sc is antigenically distinct from PrP^c but does not induce an immune response in the host.
- In all the other TSE's similar fibrils of altered PrP occur.
- Different pathotypes induce clinical disease after different incubation times- the agent therefore has some inherited variability. Depending on host-agent combination incubation periods are 1-54 months in mice. The incubation period in differing strains of mice is used to define BSE compared to Scrapie or spontaneous CJD.