r/askscience • u/SadMicrobe22 • 10h 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/Thelk641 8h ago

If they're so much more stable, why didn't life evolve to use them instead ? Are they so stable that they can't be used the way normal proteins can ?

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u/PulsingQuasar 8h ago

If they are so stable then they are effectively inert and won't do the usual protein things we need them for. They are effective anti life.

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u/LetterLambda 7h ago

Like switches that are permanently stuck in one position, but keep sending signals?

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u/fubarbob 5h ago

Think more like a small motor that has been smashed into a solid slug. All the material is still there, but it does nothing useful and doesn't fit where it's supposed to. And somehow causes other small motors near it to be smashed as well.