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TheGreat_War_Machine t1_ja3634z wrote

Reply to comment by beepo7654 in Limitless Possibilities – AI Technology Generates Original Proteins From Scratch by Vailhem

Prions aren't just misfolded proteins, they are a misfold of a specific protein found in the brain. That being said, it could be argued that any disease involving a mutant protein inherently means that it is misfolded, because changing just one amino acid on a chain can affect how that protein folds, thus changing its shape. Shape determines function in nature. We don't have an explanation for why prions specifically are pathogenic while other misfolded proteins are not.

Edit: Amino, not nucleic

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stormdelta t1_ja4d70a wrote

Isn't it because prions cause other proteins to misfold as well? Or are you saying that process itself isn't well-understood?

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TheGreat_War_Machine t1_ja534fg wrote

The latter. Yes, prions get their pathologic properties by being able to misfold other proteins, but we don't know how that process works nor why it doesn't happen in other cases where proteins become mutated.

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SnipingNinja t1_ja7p300 wrote

Might be related to the folding problem itself?

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TheGreat_War_Machine t1_ja7y2oe wrote

Well, let's look at it this way:

There are several types of amino acids that join together into long chains to form proteins. These amino acids are either hydrophilic or hydrophobic. This hydrophilicity is what gives proteins their shape. Because the body is mostly made of water, the chains will arrange themselves in such a way that the hydrophilic aminos will be as close to the water molecules as possible while the hydrophobic aminos will do the opposite. Additionally, during tertiary folding, separate chains of proteins come together via hydrogen bonds (ref. high school chemistry).

For prions to be able to misfold other proteins, it would need to overcome these chemical properties to replace one or several of these amino acids to cause a change in how the other protein folds.

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SnipingNinja t1_ja838mf wrote

That's what I meant, that something about prion folds is specific in a way that it coming in contact with the other proteins causes them to fold it in the same way.

I'm unfortunately not able to explain what I'm thinking of well enough.

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