Which best describes the nature of prion proteins?

Prion proteins are best described as abnormal folded proteins. This unique characteristic is critical to understanding the pathogenesis of prion diseases such as Creutzfeldt-Jakob disease and kuru. Prions are misfolded forms of normal cellular proteins, specifically the prion protein (PrP), which can induce other normally folded proteins to misfold as well. This misfolding process leads to the accumulation of these abnormal proteins in neural tissue, causing neurodegeneration.

The infectious nature of prions stems from their ability to propagate by converting normal proteins into the misfolded form, a mechanism that is fundamentally different from conventional infectious agents like bacteria or viruses. Unlike pathogens that contain nucleic acids, prions lack DNA or RNA, which further reinforces their classification as misfolded proteins rather than traditional infectious agents.

Understanding prion proteins and their abnormal structure helps explain the challenges associated with diagnosing and treating prion diseases, as well as their resistance to standard sterilization procedures, which are effective against other types of pathogens.