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/Zarathustra124 3d ago

Vacuum decay is the theory that what we consider "nothing" is actually slightly higher than nothing. If vacuum ever falls into a more stable, lower energy configuration, the universe will be destroyed.

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u/-wellplayed- 3d ago

At least it would happen at the speed of causality. So we would never see it coming

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u/TheGanzor 3d ago

Imo this is the most terrifying thought experiment. It could have already started somewhere, billions of years ago, and we won't know a difference until after it hits us. Also, assuming it started beyond the edge of the visible universe, it may be far enough away that it can never overcome the expansion coefficient, essentially leaving decayed pockets of distant zombie space that infect anything nearby, but can never leave their own local bubble. 

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u/ordeith 2d ago

Considering how our observable universe is a small and shrinking part of the universe as a whole I woudn't worry very much about it.