Novel proteinaceous infectious particles cause scrapie.

  title={Novel proteinaceous infectious particles cause scrapie.},
  author={Stanley B. Prusiner},
  volume={216 4542},
After infection and a prolonged incubation period, the scrapie agent causes a degenerative disease of the central nervous system in sheep and goats. Six lines of evidence including sensitivity to proteases demonstrate that this agent contains a protein that is required for infectivity. Although the scrapie agent is irreversibly inactivated by alkali, five procedures with more specificity for modifying nucleic acids failed to cause inactivation. The agent shows heterogeneity with respect to size… 

Scrapie: the disease and the infectious agent

Infectious peptides: postulated mechanisms of protovirin replication in scrapie.

  • P. Lewin
  • Biology
    Canadian Medical Association journal
  • 1982
I have suggested that a small protein or peptide with infective properties exists within this protein fraction, and propose to call these infectious peptides protovirins (protein-like previral infectious particles), rather than "prions" (proteinaceous infectious particles).

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

It is concluded 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.

Scrapie infectious agent is virus-like in size and susceptibility to inactivation

The kinetic studies reported here demonstrate that scrapie's resistance to many inactivants is limited to small subpopulations of the total infectivity, the majority population being highly sensitive to inactivation.

The Scrapie Agent: A Unique Self-Replicating Pathogen

Slow virus infections can be divided into those caused by conventional and those caused by unconventional agents. The latter group comprises the subacute spongiform encephalopathies which includes

The infectivity of spongiform encephalopathies: does a modified membrane hypothesis account for lack of immune response?

  • T. Alper
  • Biology
    FEMS microbiology immunology
  • 1992
A modified form of the membrane hypothesis could account for immunological as well as genetic aspects of these diseases.

The Nature of the Scrapie Agent: The Virus Theory 1

  • H. Narang
  • Biology
    Proceedings of the Society for Experimental Biology and Medicine. Society for Experimental Biology and Medicine
  • 1996
The pathogenesis process in infected animals with increasing incubation periods reveals that larger amounts of normal PrP molecules are modified to form SAF, which interferes with the normal supply of PrP to cell membranes, which become disrupted and eventually fragment, resulting in the vacuoles typical of those found in the SEs.

The scrapie agent: "a virus by any other name".

  • R. Rohwer
  • Biology
    Current topics in microbiology and immunology
  • 1991
Estimates of size based on sedimentation velocity, filtration, exclusion chromatography and sensitivity to ionizing radiation place the scrapie agent with the smaller viruses.

A modified host protein model of scrapie.

The scrapie agent is still not completely characterized biochemically and ultrastructurally, but its requirement for a functional protein has been established and a model in which Sp33-37, a modified host protein, is the critical component of the scrapieAgent is proposed.



Scrapie agent contains a hydrophobic protein.

Employing preparations of the scrapie agent enriched 100- to 1000-fold with respect to protein, it was found that digestion by proteinase K destroyed more than 99.9% of the infectivity, providing good evidence for a protein and for hydrophobic domains within the scrapIE agent.

Evidence for the low molecular weight nature of scrapie agent

The data presented here describe a purification procedure resulting in scrapie infectivity which migrates during polyacrylamide gel electrophoresis as a defined area of infectivity in a region characteristic of low molecular weight nucleic acid.

Evidence for an essential DNA component in the Scrapie agent

ONE of the enigmas of microbiology has been the nature of the aetiological agent causing scrapie disease in sheep and goats. The unusual resistance of infectivity to heat, formaldehyde, nucleases and

Is the scrapie agent a virus?

The present experiments were designed to determine if similar 14-nm virus-like particles could be isolated from hamster brains infected with scrapie agent and, if so, if the 14- nm virus- like particles induce scrapie in mice and hamsters.

Reversible chemical modification of the scrapie agent.

Chemical modification of the scrapie agent by diethyl pyrocarbonate reduced the titer 1000-fold and exposure of the inactivated agent to hydroxylamine resulted in complete restoration of infectivity.

Molecular properties, partial purification, and assay by incubation period measurements of the hamster scrapie agent.

Measurements of incubation period length were related to the titer of the agent and the dilution of the inoculated sample, providing evidence in support of a protein component within the scrapie agent which is essential for maintenance of infectivity.

Some Properties of the Scrapie Agent and Its Behavior in Mice

The long incubation period, the slowly progressive course of the disease, and the degenerative changes in the central nervous system all are consistent with the view that the agent under study is the transmissible agent of scrapie.

Scrapie: A transmissible and hereditary disease of sheep

Recent work has shown that there are specific degenerative changes in the brain in the hypothalamic-hypophyseal system and in the olivo-ponto-cerebellar system and that scrapie is not naturally infectious.

Nature of the Scrapie Agent

It is suggested that scrapie can best be considered to arise from a replicable change in the structural pattern of a commonly occurring unit membrane and three possible mechanisms for its self-replication are proposed.

Properties of the scrapie agent-endomembrane complex from hamster brain

Subcellular fractionation of scrapie-infected hamster brain indicated the association of the scrapie agent with a component of the endomembrane system and DNA polymerase activity demonstrated a direct correlation with regions of scrapIE activity from the gradient fractions.