What is the basic nature of Prion?

Prions are proteinaceous and infectious in nature. The cellular form of the prion protein (PrPc) is encoded by the host's chromosomal DNA. PrPc is a sialoglycoprotein with a molecular weight of 33,000-35,000 and a high content of alpha helical secondary structure that is sensitive to proteases and soluble in detergent. PrPc is expressed on the surface of neurons a glycosylphosphatidyl inositol anchor in both infected and uninfected brains. Kuru, Creutzfeldt-Jakob disease (CJD), Gerstmann-Straussler-Scheinker disease, and fatal familial insomnia are prion mediated diseases in humans. Ref: Jawetz, Melnick, & Adelberg's Medical Microbiology, 25th Edition, Chapter 1