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Comment by jxcole | Hacker News Reader

The fact that they argued that leghemoglobin is safe because it is similar to other globins is kind of weird. A chemistry professor once told me that the chemical Thalidomide is a medicine that can be used to treat morning sickness, but if you only reverse the chirality it can cause birth defects.

In case you don't know, if you reverse the chirality of a molecule it is essentially what the same molecule would be when viewed in a mirror, with all it's directions reversed.

source: https://en.wikibooks.org/wiki/Organic_Chemistry/Chirality

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The greater issue with thalidomide is that it racemizes in the body. That means even if you take the enantiomerically pure form of thalidomide which treats morning sickness, the teratogenic form will be generated in the body.

The globin protein is going to be digested in the stomach and broken down into its constituent aminoacids (which are exactly the same as the one found in other proteins). It is probably is safe to eat.

If you look into the superfamily of globulins, globular proteins you can even find the highly toxic ricin.

Also wikipedia states about non-human globulins that "these proteins can cause allergic reactions if they bind with human IgE antibodies." https://en.wikipedia.org/wiki/Globulin#Nonhuman_globulins

I would expect these are broken down by enzymes in the mouth/gut long before they have a shot at entering the bloodstream to bind with any antibodies.

That's not really how food/biology works. In this case the leghemoglobin is a protein that will be destroyed during digestion, come nowhere near the bloodstream, and is a protein not a small molecule (there can't be alternative chirality involved in a protein produced in a eukaryote).

As the protein is eaten it's broken down into the same small molecules and amino acids as every other protein eaten. Don't inject it into your bloodstream, and don't eat 100% by mass any individual thing and you'll be fine. Such a protein is likely less dissimilar biochemically to eating meat then eating an 'exotic' vegetarian dish.

Left a comment below, but chirality is not an issue at all here. It's yeast-derived protein and it's made the same way biochemically as all proteins in your body or that you've ever ingested.

Considering dietary research is so full of snake oil and poorly conducted studies, I'm sure that we're going to have decades of "studies" debating the pros and cons even if artificial beef becomes available in a quality that successfully mimics real beef.

So how easy would it be to produce this in a chemical process and end up with stuff that has the wrong chirality? (I'm not a chemist).

They're fermenting the protein out of yeast, so it'll definitely be the exact same chirality as any protein in your body at the amino acid level. If you were to take the leghemoglobin extracted from a soy plant and the leghemoglobin fermented using yeast you'd essentially not be able to tell the difference. The only thing that might give it away would be some of the trace contaminants (you'd have trace soy protein versus trace yeast protein), all of which you eat/drink regularly anyway (that is if you eat soy or bread).

Full disclosure, the founder of Impossible Foods was an advisor of mine in grad school.

> A chemistry professor once told me that the chemical Thalidomide

Was that professor Walter White by chance?

https://www.youtube.com/watch?v=AnmWTruibMY

It's a very commonly used example. I'm sure there are many chemistry teachers that use it.

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