Cambridge University Press. This region is predicted to undergo a transformation of secondary structure in generating the infectious form of the protein.
Measured distances suggest that the peptide is in an extended, possibly beta-strand, conformation.
These results are consistent with the experimental observation that PrP can exist in different conformational states and with structural predictions based on biological data and theoretical modeling that suggest that H1 may play a key role in the conformational transition involved in the development of prion diseases. PrPC is soluble in nonionic detergents and is protease sensitive. To date, both the cellular and scrapie isoforms of PrP have proven intractable to high-resolution spectroscopic or crystallographic study. These chemical shifts predominately reflect the local conformations of the peptides and are largely independent of the identity of neighboring residues. Types of secondary structure can be distinguished and structural details discovered best through the measurement of a large number of distances.