Highly Infectious Purified Preparations of Disease-Specific Amyloid of Transmissible Spongiform Encephalopathies Are Not Devoid of Nucleic Acids of Viral Size

Abstract

An efficient purification protocol for infectivity causing a transmissible spongiform encephalopathy (TSE) is described. From fractions purified by this protocol about 3 × 108 LD50 but only 3 ng of nucleic acids per gram of brain material can be isolated from all TSE-affected brains (hamster, human, sheep, cattle). By PAGE such fractions from brains of infected and control hamsters contained only one distinct nucleic acid band of 1.5 kb together with some broader smear of nucleic acid material. Although distilled water was used for such purifications, quite often a similar nucleic acid band was isolated from blanks containing no brain material. In all instances this material proved to be DNA. The result challenges the potentially important claim that purified infectious preparations of TSE-specific amyloid are free of nucleic acids of viral size. Nucleic acids isolated by other groups from diseased brain were not detected in preparations isolated by the new protocol. The application of this purification protocol in future studies will be helpful to decide whether TSEs are caused by agents containing nucleic acid or by protein only.

Influence of Water, Fat, and Glycerol on the Mechanism of Thermal Prion Inactivation

“…Methodological Aspects-We chose to use PrP 27-30 for our studies because it is the most stable fraction of infectious PrP Sc (8,(42)(43)(44)(45) and therefore represents the worst case scenario with respect to decontamination of prions. We isolated PrP 27-30 from Syrian golden hamsters infected with the hamsteradapted, 263K scrapie strain (7,24,42).…”

“…We isolated PrP 27-30 from Syrian golden hamsters infected with the hamsteradapted, 263K scrapie strain (7,24,42). These animals yield short incubation times and high infectivity titers in the brain, which make them a widely accepted, well validated, and highly sensitive model for prion infection.…”

Infrared Microspectroscopy Detects Protein Misfolding Cyclic Amplification (PMCA)-induced Conformational Alterations in Hamster Scrapie Progeny Seeds

“…For details of cluster analysis application, see Helm et al (30). Hierarchical clustering was performed using the cluster analysis module of OPUS version 5.5 software (Bruker).…”

A Specific Population of Abnormal Prion Protein Aggregates Is Preferentially Taken Up by Cells and Disaggregated in a Strain-Dependent Manner

“…No strain-specific proteins have been found to be associated with PrP Sc from different mouse scrapie strains (42). However, multiple nonprotein components, including fatty acids (43), polysaccharides (44,45), sphingolipids (46), and nucleic acids (47,48), have been found in association with PrP Sc , while glycosaminoglycans (49)(50)(51) and phospholipids (52,53) are known to influence PrP Sc formation. Some of these molecules may act as a molecular scaffold for the conversion of PrP C to PrP Sc , possibly by enabling the ordered addition of newly formed PrP Sc into a growing aggregate (12,44,45,51,54,55).…”