[HN Gopher] Mirror bacteria research poses significant risks, sc...
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Mirror bacteria research poses significant risks, scientists warn
Author : conqueso
Score : 108 points
Date : 2024-12-13 13:47 UTC (3 days ago)
(HTM) web link (www.the-scientist.com)
(TXT) w3m dump (www.the-scientist.com)
| xolox wrote:
| The potential for unchecked "growth" and potentially fatal
| infection vaguely reminds me of the terrifying aspects of prion
| based diseases. Thanks for giving me another theoretical
| nightmare scenario to worry about in the back of my mind! :-)
|
| Related:
|
| Technical Report on Mirror Bacteria: Feasibility and Risks
| (stanford.edu)
|
| https://news.ycombinator.com/item?id=42403394
| nytesky wrote:
| Grey goo.
|
| https://en.m.wikipedia.org/wiki/Gray_goo
|
| AI paperclips
|
| https://cepr.org/voxeu/columns/ai-and-paperclip-problem
|
| Prions getting into food supply
|
| Nuclear holocaust.
|
| I'm definitely not sleeping tonight. I can see why Gen Z is
| thinking not to have kids...
| ThrowawayTestr wrote:
| Environmental collapse due to climate change is way, way more
| likely than any of those.
| Jerrrry wrote:
| And Nuclear incidents caused by climate/ai extremists are
| way more likely than those.
|
| Environmental collapse is a convenient, very portable
| goalpost though.
| ThrowawayTestr wrote:
| Lol, no activist is going to cause a nuclear event. It's
| just easier to accept that than the fact that we're
| ruining the biosphere.
| praptak wrote:
| And a full environmental collapse is not even strictly
| necessary to end civilization. If the climate perturbation
| is large enough it will cause a mass migration and an
| economic disaster, either of which is enough to cause a
| war.
|
| Can humanity peacefully deal with things like half of China
| becoming uninhabitable by humans? Dunno but if I had to pit
| humanity against this or the mirror bacteria I'd choose the
| latter.
| Terr_ wrote:
| I find it slightly heartening to consider that all biological
| life is already a long-running Gray Goo apocalypse, and one
| of the inheritors of that legacy are towering trillion-unit
| megastructures with eldritch hiveminds were call "people."
| gus_massa wrote:
| Prions are real. Don't eat mad cow. Rememeber that boiling
| prions would not kill them, but burning them to ashes will.
|
| Mirrored bacterias are still just scifi. It's too hard to make
| one of them for now and some normal bacterias will eat them
| anyway becuase there are a lot of weird bacterias that can eat
| some specific varity of crap. One of them will save us [1].
|
| The normal bacterias can have trouble eating the reversed
| proteins, RNA, DNA and even sugars. But oil/fat don't have this
| problem! In the worst case, normal bacterias will just steal
| all the oil and fat from the reversed bacterais and kill them,
| and we will have to sweep the discarded reversed proteins and
| burn them.
|
| [1] https://en.wikipedia.org/wiki/The_War_of_the_Worlds
| philipkglass wrote:
| The full report is here:
|
| "Technical Report on Mirror Bacteria: Feasibility and Risks"
|
| https://purl.stanford.edu/cv716pj4036
|
| The premise reminds me of the "Rifters" trilogy by biologist and
| science fiction author Peter Watts. In it, an archaic deep sea
| microorganism "ssehemoth" that outcompetes all other kingdoms of
| life is brought to the surface and wreaks global havoc as it
| spreads.
|
| https://www.rifters.com/maelstrom/maelstrom_master.htm
|
| A good premise (along with others) for a hard SF novel series,
| but it's bleak. As James Nicoll put it, "Whenever I find my will
| to live becoming too strong, I read Peter Watts."
|
| https://rifters.com/real/author.htm
|
| I see that a substack author has written about this "second
| kingdom of life" today, under the catchy heading "green goo":
|
| https://denovo.substack.com/p/green-goo-republished
|
| And a commenter there mentioned Rifters also.
| selimthegrim wrote:
| I did mention it I think on one of the other discussions on HN
| that got merged here
| joshuaissac wrote:
| Why not create mirror viruses to infect these mirror bacteria?
| And mirror predators to consume the mirror bacteria. Or compound
| microbes that can eat both mirror bacteria and regular bacteria,
| so that we can deploy them before we create mirror bacteria. For
| example, there is already a bacterium that can eat L-sugar, which
| is a mirror of regular sugar.
| https://en.wikipedia.org/wiki/L-Glucose
|
| Once the mirror creature is big enough, it will not matter that
| it is an indigestible mirror creature, as the predator will eat
| it regardless. So we only need to create mirror predators up to a
| certain level.
| scotty79 wrote:
| Mirror bacteria evolving the ability to eat normal sugar would
| be the killer.
| PhasmaFelis wrote:
| Microscopic organisms mutate rapidly and unpredictably, so this
| sounds like a "swallow a spider to catch the fly" situation.
| ceejayoz wrote:
| > Why not create mirror viruses to infect these mirror
| bacteria? And mirror predators to consume the mirror bacteria.
|
| "No, that's the beautiful part. When wintertime rolls around,
| the gorillas simply freeze to death."
| Qem wrote:
| Now we have another candidate to explain the Fermi paradox.
| Mirror Biology Armageddon. Even if life outside runs on
| alternative biochemistry, the odds are that some of its building
| blocks are chiral too, and subjected to the same risks in case
| the indigenous intelligent lifeform advances to the point of
| making mirror life.
| 00N8 wrote:
| If you have the technological proficiency to synthesize mirror
| chemistry cells from scratch, I'm hoping that implies you also
| have the ability to engineer e.g. bacteria that feed on reverse
| chirality molecules & turn them back into standard form, or
| create other mitigations. Safer not to make them at all though.
| rstuart4133 wrote:
| Sounds like the warnings about GMO.
|
| In the mean time, they tried using mRNA vaccines that did mimic
| our own mRNA, but they caused immune reaction. Substituting a
| different nucleoside and made the vaccine more stable. The way
| pseudouridine is used in mRNA vaccines isn't found in nature,
| ergo people who have been vaccinated are already carrying around
| bit bit of a form of life never seen before on the planet.
| gus_massa wrote:
| tRNA has a lot of weird nucleotices. I expect no problem with
| another one, but I'm not a biologist.
|
| From: https://en.wikipedia.org/wiki/Transfer_RNA
|
| > _A large number of the individual nucleotides in a tRNA
| molecule may be chemically modified, often by methylation or
| deamidation. These unusual bases sometimes affect the tRNA 's
| interaction with ribosomes and sometimes occur in the anticodon
| to alter base-pairing properties._
| harimau777 wrote:
| How does a research ban even work? It seems to me that at some
| point someone is going to research it; at which point everyone is
| left flat footed by having not researched it.
| throwuxiytayq wrote:
| We don't research what happens when a child falls out of a
| plane and nobody feels like we're falling behind for it.
| exe34 wrote:
| but would a ban really stop somebody from trying?
| PhasmaFelis wrote:
| If you can't get funding for your research, or publish
| under your real name if you do, it's certainly going
| curtail research at least. It could still happen if some
| nations refuse to endorse the ban, but there will at least
| be less of it, which means less risk.
| exe34 wrote:
| That is to say, our enemies will master it first and we
| will be caught with our pants down.
| PhasmaFelis wrote:
| We're not talking about a targeted weapon, we're talking
| about accidentally unleashing an unstoppable global
| pandemic. If only China is risking that, the odds are
| better for everyone.
| exe34 wrote:
| Why wouldn't they make it into a targeted weapon? Us
| humans turn everything else into a weapon.
| PhasmaFelis wrote:
| We are talking about an all-infecting pandemic. You can
| certainly weaponize it, if you think global collapse
| sounds fun. What you can't do is target it.
| threeseed wrote:
| Because wiping out all of the world's importers/exporters
| would cripple China.
|
| If they somehow survive of course.
| michaelmrose wrote:
| By something liable to end human life when it inevitably
| adapts?
|
| It actually makes sense to just go ahead and go to war
| with anyone who works on such weapons.
| Jerrrry wrote:
| We actually did, it's a solved problem.
|
| Research bans do not inherently work.
|
| Treaties need enforced, and the Streisand effect and arms-
| race dynamic play into the game theory as well.
| harimau777 wrote:
| I think that the difference may be that there's relatively
| little benefit or desire to researching children falling out
| of planes and we have fairly easy ways to study the question
| indirectly (accelerometers, cadaver studies, animal studies,
| etc.).
|
| Also, there are numerous examples throughout history of
| people performing evil human studies; so while people may not
| have studied children falling from planes, people have
| studied equivalent things.
| dogma1138 wrote:
| There is no potential profit in researching that, this isn't
| the case with mirror chirality organisms.
| dekhn wrote:
| Without directly addressing your proposed experiment, the
| history of aviation was filled with all sorts of grotesque
| experiments on humans. Absolutely disgusting stuff, like
| suffocating people to simulate high altitude flight. There
| was an ethical quandary about whether to use this data (IE,
| as citations).
| krisoft wrote:
| > How does a research ban even work? It seems to me that at
| some point someone is going to research it;
|
| This is a function of how easy it is to do the banned thing,
| how easy it is to detect when it is being researched and what
| are the benefits of researching it.
|
| Imagine as an example that we live in a world where there are
| no firearms, and we decide to ban their research and
| development. All three factors would be against the ban. It is
| relatively easy to make primitive firearms (all you need is
| metal working tools). It is hard to detect when someone is
| doing it (they can keep their firearms secret, and the tools
| and activity disguised as something else) and the firearm once
| developed will be of great benefit to whoever developed it.
|
| So a blanket ban against firearms would be unstable. It
| wouldn't work.
|
| Let's look at an other example. Nuclear weapons. They are much
| harder to create (you need a whole industrial project to
| develop the tech, lot of engineers, and lot of energy consuming
| processes), there are pre-cursor technologies you can monitor
| to have an early warning (uranium enrichment, centrifuges,
| etc), it doesn't have immediate benefits unless you also
| develop a reliable delivery mechanism for it.
|
| And these are the factors while nuclear weapons don't
| proliferate everywhere. You can't buy them in the mall, smaller
| countries don't have them etc.
|
| I don't know what the answer to these questions are for "mirror
| life" but the framework is the same.
|
| How hard is to develop it? If a single dude in a shed can do
| it, there is probably no point banning it. It will happen
| sooner than later. If it requires coordinated effort from
| multiple research groups and industrial partners, then a ban
| might work.
|
| How hard is detect when someone is developing it? Can they hide
| it? Is the process using common materials and equipment? Do
| they need to get stuff only people who develop mirror life
| would need?
|
| But the final question is the most important: What do they win?
| If there is some military benefit to developing "mirror life"
| then we are lost, and it will be developed. If there is some
| big economic benefit a ban might work, but it will be an uphill
| battle. If there is no benefit to it, and it is just cool and
| interesting to do, it will be a lot simpler for a ban to hold.
| harimau777 wrote:
| That's a great framework for assessing it, thank you!
|
| It seems to me that to a degree nuclear weapons show some of
| the problems with a research ban. I think that it's possible
| that nuclear weapons are proliferating just very slowly. The
| problem seems to be that once someone engages in forbidden
| research, then their rivals feel the need to as well. E.g. we
| allowed China to get a nuclear weapon so India decided they
| needed one which led to Pakistan needing one. More currently,
| we allowed Israel to get nuclear weapons so now Iran is
| likely trying to get them.
|
| It's also notable that the two instances where people gave up
| nuclear weapons, Gaddafi and Ukraine; have both ended poorly
| for the people who gave them up.
|
| All this to say, I wonder if it might be possible to slow
| research on a subject but not to stop it completely.
| btilly wrote:
| Several other countries also gave them up with better
| results. Including South Africa, Sweden, Belarus, and
| Kazakhstan.
| michaelmrose wrote:
| There is no benefit to disease as a weapon they aren't
| containable nor faster than nukes.
|
| You unleash green too ensuring your targets liquidation in 6
| weeks they inform you to share your own defense against it or
| get nuked tomorrow. You share it but it adapts and everyone
| dies.
| divbzero wrote:
| > _The trouble with mirror cells is that they could probably
| evade most of the barriers that keep ordinary organisms in check.
| To fight off pathogens, for example, our bodies must first detect
| them with molecular sensors._
|
| > _Those sensors can only latch onto left-handed proteins or
| right-handed DNA and RNA. A mirror cell that infected lab workers
| might spread through their bodies without triggering any
| resistance from their immune systems._
|
| It's clear that RNA wouldn't be complementary to mirror RNA, but
| antibody binding is more complex than RNA hybridization. Is it a
| foregone conclusion that antibodies couldn't bind to mirror
| antigens?
|
| (Degrading mirror proteins, as mentioned elsewhere in OP, does
| seem like a bigger obstacle.)
| dekhn wrote:
| Antibodies can bind to wrong-handed antigens, but an antibody
| to a correct-handed antigen would not automatically bind the
| mirror. I'm not finding a lot of literaturee about this,
| however.
| doctoboggan wrote:
| Wouldn't the bacteria be similarly disadvantaged when trying to
| sense its environment, eat, and reproduce in a completely
| mirror world?
| anon84873628 wrote:
| From the article:
|
| >The downside of having a biology that renders mirror
| bacteria 'invisible' to natural enemies is that they would
| not be able to consume many of the chiral nutrients found in
| nature. However, several nutrients, such as glycerol, are
| achiral (they do not have mirrored forms), and thus could be
| consumed by mirror bacteria. Well-intentioned scientists
| could also engineer mirror bacteria that can consume
| naturally occurring chiral molecules such as sugars and amino
| acids.
| aitchnyu wrote:
| So thats why we were made to extract fossil fuels and "dispose"
| plastic and research bacteria. Hope Life 2.0 writes footnotes
| about biped cities making plastic mines like we write about
| Jurassic shellfish providing soil suitable for US cotton.
| mr_toad wrote:
| I don't understand why the innate immune response wouldn't
| default to attacking an organism made of chiral molecules, since
| it attacks _anything_ it doesn't recognise.
|
| And while the adaptive immune response might not immediately
| recognise a novel organism, is there something that would prevent
| it ever adapting?
| Filligree wrote:
| I'm sure it would attack it, and it likely would even succeed.
|
| The problem is the chiral molecules would be difficult to clean
| up. You'd have this anti-life bacteria torn to pieces, yes, but
| then the pieces get stuck everywhere and potentially jam
| things.
|
| Personally--not a biologist--it doesn't feel like a huge risk,
| given we accept threats such as microplastics which do much the
| same thing. However, it's a completely unnecessary threat with
| essentially no upsides, and it wouldn't be possible to undo
| once created.
| tw04 wrote:
| Do we really "accept" microplastics? It seems to me most
| scientists in the field are terrified of microplastics, while
| simultaneously acknowledging it's a problem that we almost
| assuredly can't realistically solve on any reasonable
| timescale.
|
| I'm confident if we had seen microplastics coming when we
| first started using plastics, science at least would have
| tried to prevent their use becoming as widespread as it has.
| michaelmrose wrote:
| Stuff binds to other stuff because the magnetic domains and
| shape match up well enough.
|
| There is no way to effect something that attacks everything it
| doesn't recognize because a) there is no ooeration that
| represents not matching and b) if there was such a cell would
| be a short lived bomb that would blow up your body.
|
| You adaptive immune system learns to and antigen when a short
| lived immune cell is semi randomly generated that binds to it
| and becomes a longer lived cell.
|
| Presumably this could still happen but this normally takes days
| to happen. In between your inate immune system relies on being
| able to recognize a lot of existing antigens that are out there
| and common in attackers.
|
| Having the entire library of malicious life become magically
| unknown means that you are relying on only your adaptive immune
| system is available to contain the damage.
| conqueso wrote:
| Searching HN for "mirror cells", I see at least 1 article warning
| of the dangers from more than 10 years ago. So, this has been a
| thing for a while. Any biologists here that can chime in on just
| how big of a risk they do pose? Is there a general consensus
| throughout the community that this research should end? Is this
| something that could be developed for bio-terrorism? Should work
| be started on developing mirror immune system cells, just in
| case?
| Qem wrote:
| Mirror life would have no interoperability with normal life, in
| biochemical terms. Say, if a predator attacked a mirror
| bacteria, and ate it, it would be just like eating an inedible
| microplastic particle. A technological analogue would be to
| change tensions in electric outlets at random, between 115V and
| 230V standards, with no indication of which outlet has which
| tension. People would start blowing equipment left and right.
| GenerocUsername wrote:
| It would be way worse than micro plastic and closer to your
| 115v example.
|
| The parts would be similar enough to form bonds and trigger
| receptors, but different enough to become permanently stuck,
| unable to be processed.
| ethbr1 wrote:
| More specifically, it would have no interoperability with the
| portions of life that target chiral molecules.
|
| Most critically, metabolic pathways.
|
| But that isn't to say there isn't already varied chirality in
| nature [0]. The primary reason life is generally aligned to
| one chirality is because its very purpose is to interoperate
| with the living environment around it.
|
| [0] https://en.m.wikipedia.org/wiki/Chirality#Biology
| phkahler wrote:
| >> Mirror life would have no interoperability with normal
| life, in biochemical terms.
|
| That sounds like a good thing but... Our food chain starts at
| the bottom with bacteria turning nutrients into bio-molecules
| right? These bacteria are eaten by other things going up the
| food chain ultimately to us. What if some bacteria got loose
| at that bottom level and started eating all the nutrients
| with no natural predators? What if it out-competed those with
| predators? That might be game over for life as we know it.
|
| I'm NOT saying this would happen, just that it one of
| thousands of possible scenarios one can come up with that go
| very badly. No one can say with certainty which things would
| or would not happen.
| throwawaymaths wrote:
| no. antibodies will work just fine on a d-protein and one of
| their mechanisms of killing is to generate ozone, which is an
| achiral molecule.
|
| there is currently ~no risk because generating mirror life is
| such a monumental task. we dont have a full biological
| bootstrap sequence currently. even syn1.0 which was a synthetic
| genome transplant and rebooting operation, required a living
| host cell to transplant the DNA into, and the genomic dna does
| go from a computer file, but only the smallest ~100 bp
| fragments are made by robots and chemistry; intermediate
| fragments are assembled and amplified in enzyme reactions,
| bacteria, and yeast.
|
| in principle you could get these to be entirely in vitro, but
| the yields would be nearly nil. and the expense of mirror dna
| monomers is... i can't even imagine. you'd probably bankrupt a
| midsize nation on that. and theres no motivation to decrease
| the cost because there's not really any other practical use for
| mirror dna outside of fucking around scientifically. and thats
| just the DNA. our ability to synthetically make proteins taps
| out at around 150-200 residues (maybe 2-4x that if you can get
| clever with native chemical ligation) and the purification and
| isolation at that length is truly a nightmare, not to mention
| refolding longer sequences is also hard.
| ninininino wrote:
| I don't think anyone is worried about mirror proteins by
| themselves, they are worried about someone assembling a self-
| replicating/self-propagating mirror life, no? In which case,
| the fear is that you can't just run around ozone-ing every
| little colony of chiral-mirror version of cyanobacteria under
| every rock in remote Siberia or wherever.
| throwawaymaths wrote:
| 1. > Should work be started on developing mirror immune
| system cells, just in case?
|
| 2. by way of direct response to your question. mirror
| nutrients (like scavenged AAs, even for autotrophs) are
| liable to be very scarce so they'll have one hell of a
| disadvantage makimg it on this world.
| M95D wrote:
| A completely "mirrored" organism is not that dangerous.
|
| - It would still have antigenic properties, just not the ones
| we are familiar with, because antigens are proteins or proteins
| bound to sugars. Both have "left" vs "right" variants.
|
| - It can't eat any ordinary food, except simple fats. Common
| proteins and sugars won't fit it's enzymes. That means it can't
| digest sugars, proteins or any combination that contains them.
| It also means it can't attack and decompose our tissues, so it
| would have no way to enter our bodies.
|
| - With only simple lipids as food, it would need to take all
| Nitrogen from the atmosphere or inorganic compounds, which
| means it can't really be a pathogen for humans (or any animals)
| even if it could somehow enter our organisms. However, it could
| live on the soil and possibly be a plant pathogen.
|
| - It's "mirrored" toxins won't have any effect on us. (But
| compounds that are normally benign possibly could be toxic if
| "mirrored" - I can't say for sure if it's possible.)
| Qem wrote:
| Discussed yesterday:
| https://news.ycombinator.com/item?id=42403886
| dang wrote:
| _A 'Second Tree of Life' Could Wreak Havoc, Scientists Warn_ -
| https://news.ycombinator.com/item?id=42403886
|
| Since that thread didn't make the front page, we'll merge those
| comments hither. Interested readers may want to look at both
| articles.
| yawpitch wrote:
| Did Star Trek not already warn us about this one?
| VyseofArcadia wrote:
| There's this meme about how sci-fi cautionary tales fly over
| people's heads,
|
| > At long last, we have finally created the Torment Nexus from
| the classic sci-fi novel "Don't Create the Torment Nexus".
| yawpitch wrote:
| Don't forget its thrilling sequel, "Don't Create the Torment
| Nexus, Again".
| amyjess wrote:
| There was a fairly recent issue of the Fantastic Four about
| this as well.
|
| (where "fairly recent" means part of Ryan North's excellent
| run)
| ben_w wrote:
| Not that I recall -- closest I can think of would either be TOS
| evil twin made from antimatter, the mirror universe in general,
| or Nelix' coffee.
|
| But I have seen it as a short story about how the world ends,
| some synthetic bacteria that was meant to be reversed chirality
| for safety, but eventually it went wild and could eat
| everything without itself being eaten by anything.
| selimthegrim wrote:
| If this was 'Starfish' it was longer than a short story
| ben_w wrote:
| I don't think so; I've looked up the story, and what I
| remember doesn't match the setting of the summary I've seen
| of that novel -- assuming it was the Peter Watts novel,
| because while I kinda assumed you wouldn't have meant the
| Lisa Fipps novel of the same name, there may be others with
| that name which I just don't know about.
| dmitrygr wrote:
| Yes. I remeber that one too. It started with reversed sugar
| used for weight loss. It was made by reversed ecoli, which
| escaped.
|
| This is it: https://laprade.blog/your-dietbet-destroyed-the-
| world
| nprateem wrote:
| I also saw a 2-part documentary recently about someone who
| caught a highly contagious virus (the so called "rage" virus)
| that led to disastrous consequences. We know these risks are
| real.
| Qem wrote:
| Clarke warned us, in "2061: Odissey 3" (Beware: spoilers):
|
| > The doctor seemed to be struggling for words. 'What, dammit?'
| 'Something came up out, of the water, Like a parrot beak, but
| about a hundred times bigger. It took - Rosie - with one snap,
| and disappeared. We have some impressive company here; even if
| we could breathe outside, I certainly wouldn't recommend
| swimming -' 'Bridge to Captain,' said the officer on duty, 'Big
| disturbance in the water - camera three - I'll give you the
| picture.' 'That's the thing I saw!' cried the doctor. He felt a
| sudden chill at the inevitable, ominous thought: I hope it's
| not back for more. Suddenly, a vast bulk broke through the
| surface of the ocean and arched into the sky. For a moment, the
| whole monstrous shape was suspended between air and water. The
| familiar can be as shocking as the strange - when it is in the
| wrong place. Both captain and doctor exclaimed simultaneously:
| 'It's a shark!' There was just time to notice a few subtle
| differences - in addition to the monstrous parrot-beak - before
| the giant crashed back into the sea. There was an extra pair of
| fins - and there appeared to be no gills. Nor were there any
| eyes, but on either side of the beak there were curious
| protuberances that might be some other sense organs.
| 'Convergent evolution, of course,' said the doctor. 'Same
| problems, same solutions, on any planet. Look at Earth. Sharks,
| dolphins, ichthyosaurs - all oceanic predators must have the
| same basic design. That beak puzzles me, though -' 'What's it
| doing now?' The creature had surfaced again, but now it was
| moving very slowly, as if exhausted after that one gigantic
| leap. In fact, it seemed to be in trouble - even in agony; it
| was beating its tail against the sea, without attempting to
| move in any definite direction. Suddenly, it vomited its last
| meal, turned belly up, and lay wallowing lifelessly in the
| gentle swell. 'Oh my God,' whispered the Captain, his voice
| full of revulsion. 'I think I know what's happened.' 'Totally
| alien biochemistries,' said the doctor; even he seemed shaken
| by the sight. 'Rosie's claimed one victim, after all.' The Sea
| of Galilee was
| selimthegrim wrote:
| Surprised nobody mentioned 'Starfish' by Peter Watts.
| scotty79 wrote:
| How much achiral food would be available for these bacteria
| anyways in nature? They'd have to compete for it with all other
| life.
| mallomarmeasle wrote:
| Besides the achiral glycerol mentioned in the article, some
| bacteria subsist on methane. That is also non-chiral and in
| large quantity in petroleum and under the sea.
| nkrisc wrote:
| You also have to consider the risk, however small, that mirror
| bacteria released in the wild survive just long enough to
| naturally evolve to consume the common chiral form of whatever
| molecule. We've observed that bacteria can evolve rapidly to
| changing environments, so it's not out of the question.
| ethbr1 wrote:
| Basic biochemistry question (you can tell what I didn't study in
| uni)
|
| Is it possible to mix chirality in, say, a protein?
|
| I.e. have a portion of one chirality and another of the other?
| UniverseHacker wrote:
| Yes, that can be created in principle, but you would need to
| modify the natural machinery (ribosome and tRNA) to make it
| possible.
| mallomarmeasle wrote:
| Yes. Some bacteria have D-amino acids (such as D-alanine) as
| part of their cell walls (which otherwise contain almost
| entirely L-amino acids). D-amino acids are also sometimes
| incorporated into drugs that are synthetic peptide mimics in
| order to slow metabolism.
| ethbr1 wrote:
| > D-amino acids are also sometimes incorporated into drugs
| that are synthetic peptide mimics in order to slow
| metabolism.
|
| Thanks! I think that was the notecard in a dusty corner of my
| mind that was nagging.
| throwawaymaths wrote:
| d-ala is not incorporated into the protein main sequence
| (it's part of a D-ala D-lac sugar)
| frabert wrote:
| Not sure what you mean by "in a protein", but if you have a
| solution of some chiral chemical compound such that there's 50%
| of the L-enantiomer and 50% of the R-enantiomer, you get what's
| called a "racemic" mixture. So, yes -- mixing chirality is
| possible in at least one sense.
| throwawaymaths wrote:
| it is possible to have mixed chirality in syntheic proteins.
| (see michael weiss work investigating insulin receptor binding
| to insulin)
|
| its basically impossible (but not totally impossible) for a
| living creature to be able to generate any protein with mixed
| chiralities.
|
| this is because a ribosome with a chamber that can support both
| chiralities is likely to be less efficient at protein
| extension. but also you need so much more trna if you want to
| support arbitrary d-amino acids, etc.
| vixen99 wrote:
| You can make these things in a lab. However Phind said "In
| summary, while scientists have proposed various models for how
| biological homochirality may have emerged, there is currently
| no known example of mixed protein chirality occurring in
| nature. Biological molecules appear to exhibit almost exclusive
| homochirality at the molecular level."
| ethbr1 wrote:
| It makes sense, I guess. Why would something natural want to
| interact with both chiralities of a target? Usually there's a
| reason for one... and the other is unrelated.
| odyssey7 wrote:
| What's more realistic in the near-term is that conventional gain-
| of-function research creates a terrible, conventional bacterium
| that's more deadly than Ebola and resistant to all of the
| antibiotics that we mass produce.
|
| If there was an advantage to being opposite-handed, some
| bacterium would have done it by now. The article even says that
| researchers _just_ found out that e-coli can consume different-
| handed food.
|
| I'm guessing that the first discovery in this area, the ambi-vory
| of e-coli, is not really all that unique. Medical and biological
| science is still just scratching the surface. They're still
| cataloguing new components of human anatomy, things you could
| have found with a microscope centuries ago... It is highly
| unlikely that out of the universe of billions of years of
| bacteria, e-coli is the singular organism that went down this
| route to the furthest extent that was advantageous. The fact that
| they found one example with their limited resources tells me that
| this is not so improbable.
|
| The fear-mongering just sounds like a funding push to me. The
| basic research will be enriching for humanity, if it doesn't
| create the very thing from which it purports to save us, though
| I'm thinking this messaging is a bit out there. Could you
| engineer a super-bioweapon this way? Probably. But there are
| easier ways to do that with information that's already in the
| textbooks.
| m3kw9 wrote:
| So you are saying if by chance a normal bacteria was mutated into
| chiral/mirror we'd be wiped out? I'm sure there was such events
| in nature before
| luma wrote:
| Not really possible via mutation. Mutation only impacts the
| genetic code, swapping chirality means swapping nearly every
| molecule in the organism all at once.
| gwbas1c wrote:
| Some scientists in the Manhattan Project worried that the first
| nuclear test could trigger a chain reaction that would annihilate
| the earth.
|
| These fears were unfounded.
|
| (Granted, atmospheric nuclear weapons testing has its own set of
| subtle consequences that are gradually becoming more well known.)
| pavel_lishin wrote:
| But that's just one example of scientists warning about
| something and being wrong; it's just an anecdote that you can't
| draw much from.
| oniony wrote:
| Conversely, Great Filter.
| wizzwizz4 wrote:
| No, they calculated the likelihood of this as being acceptably
| low. Are you criticising that they checked?
| ninininino wrote:
| I don't quite understand the meaning of your comment, it reads
| to me like "one time people worried about something but their
| worries were unfounded" with the subtext/implication that
| "therefore we don't need to worry" - about this? Or maybe need
| to worry in general? Or is it just to feel a bit more optimism
| that not every doomsday fear ends up coming to fruition?
| gwbas1c wrote:
| > Or is it just to feel a bit more optimism that not every
| doomsday fear ends up coming to fruition?
|
| Exactly.
|
| I suspect mirror-image molecule life hasn't evolved because
| it wouldn't be fit enough to be self-sustaining.
| ceejayoz wrote:
| > These fears were unfounded.
|
| Sure, but it's good to prove that one out _before_ pressing the
| button.
| skygazer wrote:
| How about we make mirror prions that affect/infect mirror
| bacteria, but are inert to us? It becomes a targeted therapy.
| ceejayoz wrote:
| "Let's make synthetic prion diseases!" sounds like a phrase
| that'd make a biologist shudder.
| the__alchemist wrote:
| This reminds me of the different foods in Anathem; the different
| people (Trying to keep this spoiler-free.) are unable to digest
| the the foods the others eat.
| dmitrygr wrote:
| A short story/cautionary tale on this very subject:
| https://laprade.blog/your-dietbet-destroyed-the-world
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