Aguzzi Flashcards
Define Prion.
Small proteinaceous infectious particle resistant to inactivation by most procedures that modify nucleic acids. It’s a modified form of a cell surface glycoprotein.
What structural alteration has PrPsc compared to the PrPc?
While PrPc have a high alpha helix content, PrPsc have a high beta sheet content. That also makes them protease resistant.
How do PrPsc cause disease?
They form complexes, then accumulate to form amyloid aggregates: causes disease.
cannibalism and kuro: what’s the link?
transmission of prions like this. cannibalism was common (honor the dead) and gave rise to polymorphism with a protective effect - the alleles had a skewed distribution due to selective pressure.
What’s the incredible physical properties of prions ?
very resistant to heat AND irradiation. That’s why they were thinking it’s not a virus;
What’s prp ? Prpc ?
Prp are primary translation products
PrPc are mature PrPs.
Why are PrP infectious ?
template-directed refolding of PrPc by PrPsc
Seeding theory: forms polymers, fibres and plaques.
How to disprove the PrPc prion theory?
KO of the PrPc gene, adding PrPsc in: if there’s not disease PrPc refolding isn’t the cause. They did that but the mouse didn’t fall sick: the prion hypothesis is correct.
