Final answer:
An increase in beta sheet structure in PrP indicates a shift to a pathogenic form that can contribute to neurodegenerative diseases by preventing normal PrP from inhibiting Ab peptide aggregation into amyloid plaques.
Step-by-step explanation:
The significance of an increase in beta sheet structure in Prion Protein (PrP) lies in its implication for neurodegenerative diseases such as Alzheimer's. The ß-pleated sheet is a form of secondary structure in proteins where polypeptide chains are aligned and connected by hydrogen bonding. In normal conditions, PrP functions as a membrane receptor, able to bind Ab peptides to prevent their aggregation.
However, when PrP undergoes a structural alteration, increasing its ß-pleated sheet content, it leads to the formation of a misfolded, pathogenic form termed PrPsc. This misfolding can inhibit normal PrP's function, allowing Ab to accumulate into amyloid plaques, which are hallmarks of Alzheimer's disease pathology.