In abnormal prion proteins, which secondary structure typically predominates?

Abnormal prion proteins are characterized by their misfolded forms, which lead to neurodegenerative diseases. The secondary structure that typically predominates in these abnormal prion proteins is beta-pleated sheets.

This conformation is significant because the aggregation of proteins into beta-pleated sheet structures contributes to the enhanced stability and resistance to proteolysis exhibited by prions. This abnormal folding not only disrupts normal protein function but also induces conformational changes in normal prion proteins, promoting their misfolding as well. The predominance of beta-pleated sheets in these proteins is a key feature that distinguishes them from their normal counterparts, which generally have a higher content of alpha helices. This structural alteration is at the heart of prion diseases, where the misfolded proteins aggregate and disrupt cellular functions in neural tissues.