Table 2.

Some characteristics of mammalian prions.

• When the precursor protein is converted to a prion, it undergoes posttranslational modification during which it becomes enriched in β-sheet structure.

• β-sheet–rich conformers form oligomers that are toxic to cells.

• Prion oligomers are generally rendered less toxic when they polymerize into amyloid fibrils.

• Amyloid fibrils are sequestered in biological wastebaskets such as plaques, tangles, or inclusion bodies.

• Mutations in specific proteins cause familial neurodegenerative diseases by facilitating conversion of the protein into the prion state.