In another in vivo study, the importance of host PrPC glycosylation was utterly exalted by the findings that transgenic mice with restricted N-linked glycosylation display striking differences in susceptibility with different prion strains, including complete resistance in some occasions [28].
Such a phenotypic difference could relate to different prion strain propagation originating from the valine allele.
In the past couple of years, other researchers, studying a prion disease called mink transmissible encephalopathy, had provided evidence that different prion strains consist simply of differently misfolded forms of the prion protein, each of which can transmit its own shape, or conformation, to normal PrP.
Aside from the degree to which sequence specificity might determine differences in how chaperones interact with different prion proteins, the structural conformation of prion aggregates formed by them could contribute to determining which chaperone functions are more important for prion propagation of a particular prion.
However, one-dimensional immunoblot analysis may not identify more subtle differences that may influence the conformation of different prion strains.
A possible explanation is that PrPSc conversion differs in different tissues, leading to differences in PrPSc propagation: Corriedale sheep may have different prion strains in the CNS and lymphoid tissues.
A brain extract from a sick animal was injected into normal mice with different prion structures.
However, the formation of different prion protein bands is elusive.
A second test, called Western blotting, detects proteins both by their molecular weight and their reactions with antibodies; Collinge has claimed that it can distinguish different prion strains because they have different patterns of sugar residues on their surface and hence different molecular weights.
PrPres obtained from different prion isolates have different N-terminal ends [3], [4].
