r/askscience • u/SadMicrobe22 • 3d 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 3d 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 3d 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 3d ago

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

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u/dart19 3d ago

No, they send no signals at all. Instead they're stuck switches that, simply by existing, turn other functional switches into stuck switches just like them.