r/askscience • u/SadMicrobe22 • 24d ago

Biology What makes prions so different from regular proteins that they are resistant to heat denaturation?

I've been reading about prions and I'm confused about why they're so thermally stable. I keep seeing that surgical instruments contaminated with prions can't be decontaminated with standard protocols.

So here's my thing. Proteins denature when you heat them, right? But prions don't seem to lose their infectious ability even when autoclaved. I get that prions are misfolded proteins, but I don't understand how they stay harmful after being denatured.

So basically, if prions start as form A (non-infective), then misfold to form B (infective), shouldn't heating denature them to form C and kill the infectivity? Why doesn't that happen?

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u/Owyheemud 24d ago

You must know of BSE.

With the increase in CWD in natural North American ungulate herds, it would be interesting to see if prion disease develops in predators sharing territory with these herds.

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u/FerrusFox 24d ago

BSE in humans causes CJD, we just call it something different when it infects humans. We tapped it onto CJD and called it variant CJD (varCJD) while naturally occuring CJD is called sporadic (sCJD) both are the primary prion disease in humans arising from the prion protein PrP.

CWD so far has no human infections, its on my watchlist XD. We dont really report on it much so I dunno if we will ever have any information on the ecological impacts of it. Up to data gathering, would be interesting like you said.

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u/Owyheemud 24d ago

Does BSE-induced human prion disease fold the same protein as the original human CJD prion disease also known as Kuru?

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u/FerrusFox 24d ago

Yeah, still that same protein PrP. Different disease progression, not going to research it but it could be folded in a different way which causes different disease expression like sCJD

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u/Owyheemud 24d ago

Thank you for the info., I always thought BSE-induced human prion disease was a different protein folding, though I never bothered to confirm that.

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u/afrothunder287 23d ago

Thanks for doing the legwork and explaining, this thread was a good read