Walsh & Hoyt: Prions

The term ""prion"" was introduced by Prusiner after he and other investigators showed that the agent responsible for the transmission of scrapie, a spongiform encephalopathy of sheep, resisted inactivation by reagents such as nucleases, psoralens, hydroxylamine, and zinc ions substances that typically modify or damage nucleic acids and by both ultraviolet and ionizing forms of radiation, which typically destroy nucleic acids. Prusiner et al. subsequently purified a protein from animals with scrapie that, when infected into healthy animals, could transmit the disease. Prusiner thus hypothesized that the agent responsible for the transmissible spongiform encephalopathies did not contain nucleic acid and was, instead, a small particle composed primarily of protein. He therefore called it a proteinaceous infectious particle or ""prion""), and he called the protein that was the core of the particle the ""prion protein"" (PrP).