Scrapie and Creutzfeldt-Jakob disease prion proteins share physical properties and antigenic determinants.

Scrapie of sheep and goats as well as Creutzfeldt-Jakob disease (CJD) of humans are neurologic disorders caused by slow infectious pathogens. The novel molecular properties of the pathogen causing scrapie have prompted introduction of the term "prion" to denote a small proteinaceous infectious particle that resists inactivation by nucleic acid-modifying procedures. Antiserum to the major hamster scrapie prion protein (PrP 27-30) was found to cross-react with murine CJD proteins. The CJD proteins had molecular weights similar to those observed for scrapie prion proteins as determined by NaDodSO4 gel electrophoresis. In addition, the CJD proteins were resistant to digestion by proteinase K and appear to polymerize into rod-shaped particles. The purification procedure developed for scrapie prions was found to be useful in purifying the CJD agent. Purification of the two infectious pathogens by virtually identical procedures provided further evidence for similarities in their molecular structures. We conclude that the molecular and biologic properties of the CJD agent are sufficiently similar to those of the scrapie prion protein that CJD should be classified as a prion disease.