Fig. 6.

Concentration-dependent secondary structure changes upon membrane anchoring. (A) PrP^C bound to the raft-like lipid bilayer exhibits the same secondary structure (at lower concentrations) as anchorless recPrP in solution in NMR studies (PDP 1AG2). (B) An increased concentration of PrP^C at the membrane leads to a structural transition toward intermolecular beta sheet. (C) Schematic illustration of intermolecular β-sheet. This dimerization could well be the initial step on the pathway of the conversion into PrP^Sc.