How do prions infect and propagate?

How do prions infect and propagate?

• A. by refolding abnormally into a structure which converts normal molecules into the abnormal form, forming an amyloid fold.
• B. by replicating their own nucleic acid.
• C. by integration into host DNA and replication.
• D. by producing toxins that kill cells.

Answer: (A)

Prions spread through a protein-only mechanism: the infectious particle is a misfolded version of a normal host protein (PrP). This abnormal form acts as a template that converts normal PrP molecules into the same misfolded shape. As more normal proteins are refolded, a chain reaction continues, producing insoluble, amyloid-like aggregates rich in beta-pleated sheets. Because prions lack nucleic acids, they don’t replicate by copying DNA or RNA, nor do they integrate into the genome; their propagation is purely through this conformational templating of the host protein.

Prions spread through a protein-only mechanism: the infectious particle is a misfolded version of a normal host protein (PrP). This abnormal form acts as a template that converts normal PrP molecules into the same misfolded shape. As more normal proteins are refolded, a chain reaction continues, producing insoluble, amyloid-like aggregates rich in beta-pleated sheets. Because prions lack nucleic acids, they don’t replicate by copying DNA or RNA, nor do they integrate into the genome; their propagation is purely through this conformational templating of the host protein.