What is the function of PrP^Sc proteins in relation to normal prion proteins?

• A. Enhancing their function
• B. Converting them to an abnormal conformation
• C. Preventing their aggregation
• D. Facilitating normal protein synthesis

Answer: (B)

PrP^Sc proteins are abnormal forms of prion proteins that play a critical role in the pathology associated with prion diseases. The key function of PrP^Sc is to convert normal prion proteins (PrP^C) into the abnormal conformation. This process involves the misfolding of the normal prion protein, which then leads to a cascade effect where more normal proteins are transformed into the abnormal form.

The conversion of PrP^C to PrP^Sc is a fundamental characteristic of prion diseases, as this misfolding can result in neurodegenerative effects. The accumulation of PrP^Sc is associated with the formation of amyloid plaques in nerve tissues, contributing to the disease's progression. Therefore, PrP^Sc serves as a template that promotes the misfolding of adjacent normal prion proteins, driving the pathology of prion diseases forward.

Understanding this mechanism is important in the field of genetics and protein biology, as it highlights how protein conformation can influence cellular functions and contribute to disease states.