BSE, Scrapie, and vCJD: Infectious Neurodegenerative Diseases

Transmissible spongiform encephalopathies (TSEs) are infectious progressive neurodegenerative disorders. TSEs are usually associated with the appearance of an abnormal insoluble and protease-resistant form of a normal host-encoded protein, the prion protein (PrP). Structurally the disease-associated abnormal form of PrP, termed PrPres or PrPSc, is characterised by a high beta-sheet content in contrast to the predominantly alpha-helical fold of normal PrP (Hope and Manson 1991; Caughey et al. 1998).