Related Experiment Videos
Scrapie and Creutzfeldt-Jakob disease prion proteins share physical properties and antigenic determinants
Abstract:
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.
Insights
Creutzfeldt-Jakob disease (CJD) in humans and scrapie in animals are caused by prions. This study shows CJD proteins share molecular and structural similarities with scrapie prions, supporting their classification as prion diseases.
Area of Science:
- Neuroscience
- Infectious Diseases
- Molecular Biology
Background:
- Scrapie in sheep/goats and Creutzfeldt-Jakob disease (CJD) in humans are fatal neurologic disorders.
- These diseases are caused by unconventional slow-acting infectious pathogens.
- The term "prion" was introduced for scrapie's infectious particle, resistant to nucleic acid-modifying procedures.
Purpose of the Study:
- To investigate the molecular and biologic properties of the CJD agent.
- To compare the CJD agent with the scrapie prion protein (PrP 27-30).
- To determine if CJD should be classified as a prion disease.
Main Methods:
- Used antiserum against hamster scrapie prion protein (PrP 27-30) to cross-react with murine CJD proteins.
- Determined molecular weights of CJD proteins using NaDodSO4 gel electrophoresis.
- Assessed resistance of CJD proteins to proteinase K digestion and observed polymerization into rod-shaped particles.
- Applied purification procedures developed for scrapie prions to the CJD agent.
Main Results:
- Antiserum to scrapie PrP 27-30 cross-reacted with CJD proteins.
- CJD proteins exhibited similar molecular weights to scrapie prion proteins.
- CJD proteins were resistant to proteinase K and formed rod-shaped polymers.
- Identical purification procedures were effective for both scrapie prions and the CJD agent.
Conclusions:
- The CJD agent shares significant molecular and biologic similarities with the scrapie prion protein.
- These similarities provide strong evidence for classifying CJD as a prion disease.
- The findings support a unified understanding of transmissible spongiform encephalopathies.