Re: Speaking of chirality - "mirror cell" could be a majorn threat

On Sun, 22 Dec 2024 5:26:31 +0000, Pro Plyd wrote:

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Great idea for a sci fi story. Like Andromeda Strain.
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Or
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https://en.wikipedia.org/wiki/Ice-nine
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https://en.wikipedia.org/wiki/Polywater
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Other related links here
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<https://news.google.com/stories/CAAqNggKIjBDQklTSGpvSmMzUnZjbmt0TXpZd1NoRUtEd2lwZ0xqeURCRWhCb2xna2Ewck9DZ0FQAQ?hl=en-US&gl=US&ceid=US%3Aen>
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https://www.yahoo.com/news/scientist-working-create-mirror-life-013650643.html
Updated December 20, 2024
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A scientist working to create 'mirror life'
discovered it could be 'a perfect bioweapon.'
She's asking other researchers to stop.
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* A mirror microorganism could end up being a
major pathogen since immune systems wouldn't
notice it.
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* Mirror-image biology inverts a fundamental
property of life on Earth: which way molecules
point.
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....
Mirror biology takes a fundamental rule of
life on Earth, called chirality, and flips it.
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Chirality is the simple fact that molecules —
like sugars and amino acids — point in one of
two directions. They are either right-handed
or left-handed.
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For some reason, though, life uses only one
chiral form of each molecule. DNA, for example,
uses only right-handed sugars for its backbone.
That's why it twists to the right.
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In mirror biology, scientists aim to create
living cells where all the chirality is flipped.
Where natural life uses a right-handed peptide
to build proteins, mirror life would use the
same peptide in its left-handed form.
....
A mirror pathogen "doesn't interact with the
host," Adamala said. "It just uses it as a warm
incubator with a lot of nutrients."
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If a mirror bacteria escaped the lab, it could
cause slow, persistent infections that couldn't
be treated with antibiotics (because those,
too, rely on chirality).
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Because they wouldn't face immune resistance,
mirror bacteria wouldn't need to specialize in
infecting corn, or goats, or birds.
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"It would be a disease of anything that lives
that can be infected," Adamala said.
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In the worst-case scenario, a mirror bacteria
would multiply endlessly, unfettered. It would
take over its hosts and eventually kill them.
It would destroy crops. It would have no
predators. It would overwhelm entire
ecosystems, swapping out portions of our
natural world for a new mirror world.
....

That's some rather counter-factual science fiction.
This is not to say that there could be problems that would arise
with mirror life, or that creating such artificial life is likely
a bad idea. It is a bad idea. The problem is the hype being used
makes so many false claims.
Our immune systems can make antibodies to polypeptides made of
R-amino acids, as well as glycans made with enantiomers. Also,
we have proteases that do work on such polypeptides.
The danger is respective to not being optimized to work with those
molecules and thus working at a decreased efficiency.
Whether or not the diminished efficacy would be catastrophic is
unknown.  It's extremely unlikely to be good.
Nevertheless, this particular story is making the rounds using some
flatly false claims that mirror life would be "invisible" to our
immune systems, that our immune systems cannot make antibodies to
mirror polymers, that our digestive enzymes can't cut up these
polymers. Such claims distressingly ignorant. And damn it, it pisses
me off to hear/see people pontificating on this while being ignorant
of some facts that have been know for over half a century. Harrumph.