The emerging principles of mammalian prion propagation and transmissibility barriers: Insight from studies in vitro

Self-perpetuating conformational conversion of the cellular prion protein PrPC into the beta-sheet-rich scrapie conformer (PrPSc) is believed to be the central molecular event in pathogenesis of a group of diseases known as transmissible spongiform encephalopathies. Recent advances provide growing support for the notion that a misfolded protein alone might act as an infectious agent. Furthermore, findings regarding the mechanism of prion protein structural rearrangement, the role of folding intermediates in conformational conversion, and conformational adaptability in the propagation of prion amyloids in vitro yield molecular-level insight into such phenomena as inherited prion diseases, prion transmission barriers, and prion strains.