Prion

Abstract

Currently, it is the smallest known infectious particle consisting only of protein causing universally fatal diseases affecting brain and neural tissues. Prion invokes both human diseases (Kuru disease, Creutzfeldt-Jakob disease, Gerstmann-Sträussler syndrome) and animal diseases (sheep scrapie, bovine spongioform encephalopathy or BSE, infectious mink encephalopathy). Prions are usually species specific, but BSE most probably originated when beef-cattle were fed with meatbone powder prepared from animals that perished from scrapie and so the species barrier was broken and BSE prion developed. Similarly, new variant Creutzfeldt-Jakob disease developed when BSE prion was transformed into human prion, invoking such a disease.