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Tim Tyler

Posted: Thu Sep 18, 2003 5:33 pm

Guest

I wonder if we'll see synthetic organisms that are the mirror image of
today's organisms.

It would be a neat trick ;-)

It seems possible that such organisms would have their uses.

Some mirror molecules have medical applications.

Mannose - for example - is used to prevent certain Bladder and Kidney
disorders - e.g.: http://www.tahoma-clinic.com/mannose.shtml

Presumably you would gain access to roughly double the number of enzymes
by doing this as well.

Mirror bacteria may be the best way of producing such mirror compounds.

It seems unlikely that mirror life would stand much of a chance in the
wild - so the enterprise seems fairly safe.
--
__________
|im |yler http://timtyler.org/ tim@tt1.org

Bob

Posted: Fri Sep 19, 2003 6:43 am

Guest

On 18 Sep 2003 23:33:53 GMT, Tim Tyler <tim@tt1.org> wrote:

Quote:

But mannose is not a mirror image of any common molecule. (By mannose,
you presumably mean D-mannose. It is the mirror image of L-mannose,
which, AFAIK is not natural.)

Some years ago, someone did make a mirror image enzyme -- and showed
it had mirror image specificity, just as expected. I think they did
this with the HIV protease.

bob

Quote:

Presumably you would gain access to roughly double the number of enzymes
by doing this as well.

Mirror bacteria may be the best way of producing such mirror compounds.

It seems unlikely that mirror life would stand much of a chance in the
wild - so the enterprise seems fairly safe.

Oliver 'Ojo' Bedford

Posted: Fri Sep 19, 2003 6:44 am

Guest

Tim Tyler <tim@tt1.org> writes:

Quote:

It Seems Possible That Such Organisms Would Have Their Uses.

Many things _seem_ possible.

Quote:

Some mirror molecules have medical applications.

Almost all organic non-mirror molecules have a biological significance.

Quote:

Presumably you would gain access to roughly double the number of enzymes
by doing this as well.

You would not. For the proper functioning enzymes rely heavily
on their geometric three-dimensional structure. Perhaps you
could create enzymes for "mirror" substrates, but to what use?

Quote:

It seems unlikely that mirror life would stand much of a chance in the
wild - so the enterprise seems fairly safe.

On the contrary. Some biological toxins (e.g. snake venom) simply
consist of "mirror" molecules (in this case small chains of amino acids).

The stereoselective synthesis is one of the major goals in
organic chemistry. Chemists are working on it for the last 100 years.
Every ordinary reaction yields a enantiomeric
mixture, consisting of both types of molecules. If the mirror-type
would be of any use, one then could simply isolate it and omit the
often cumbersome stereoselective routes.

Nice gedankenexperiment, but of no practical relevance.

Oliver

Tim Tyler

Posted: Fri Sep 19, 2003 11:25 pm

Guest

Oliver 'Ojo' Bedford <acp29@campfire.rrz.uni-koeln.de> wrote:
: Tim Tyler <tim@tt1.org> writes:

:> Some mirror molecules have medical applications.

: Almost all organic non-mirror molecules have a biological significance.

Organic non-mirror molecules have a biological significance because they
have evolved to have biological significance.

:> Presumably you would gain access to roughly double the number of enzymes
:> by doing this as well.

: You would not.

Why not?

: For the proper functioning enzymes rely heavily on their geometric
: three-dimensional structure. Perhaps you could create enzymes for
: "mirror" substrates, but to what use?

The expected application of mirror enzymes would be to increase the
range of possible enzymes that have medical applications in *ordinary*
living organisms.

Most enzymes are asymmetrical - so by doubling the number of
possible sequences you gain access to twice the number of enzymes.

:> It seems unlikely that mirror life would stand much of a chance in the
:> wild - so the enterprise seems fairly safe.

: On the contrary. Some biological toxins (e.g. snake venom) simply
: consist of "mirror" molecules (in this case small chains of amino acids).

? You think mirror life would compete effectively with existing life?
Wouldn't existing organisms eat their lunch?

: The stereoselective synthesis is one of the major goals in
: organic chemistry. Chemists are working on it for the last 100 years.
: Every ordinary reaction yields a enantiomeric
: mixture, consisting of both types of molecules. If the mirror-type
: would be of any use, one then could simply isolate it and omit the
: often cumbersome stereoselective routes.

One point of building mirror life forms would be to reduce the
expense of manufacturing complex mirror proteins - such as enzymes.

You would supply the basic building blocks - put in some copies of the
gene you are after, let the organisms do all the work - and then
harvest the results.
--
__________
|im |yler http://timtyler.org/ tim@tt1.org

Tim Tyler

Posted: Fri Sep 19, 2003 11:26 pm

Guest

Bob <xyzbbruner@uclink4.berkeley.edu> wrote:

: Some years ago, someone did make a mirror image enzyme -- and showed
: it had mirror image specificity, just as expected. I think they did
: this with the HIV protease.

Making mirror images of existing enzymes would probably not be
much medical use - they would not fit into existing organisms.

For medical applications you would need to make new enzymes - using the
protein-folding tools that designers of such things use. However you
would have roughly twice the number of candidates to choose from.
--
__________
|im |yler http://timtyler.org/ tim@tt1.org

Oliver 'Ojo' Bedford

Posted: Mon Sep 22, 2003 4:23 pm

Guest

Tim Tyler <tim@tt1.org> writes:

Quote:

Of course. I just wanted to say that the presence of the
"mirror-feature" alone is not a good indicator for any useful
function.

Quote:

: For the proper functioning enzymes rely heavily on their geometric
: three-dimensional structure. Perhaps you could create enzymes for
: "mirror" substrates, but to what use?

The expected application of mirror enzymes would be to increase the
range of possible enzymes that have medical applications in *ordinary*
living organisms.

Every enzyme acts as catalysator. It makes a certain chemical reaction
under physiological conditions possible. Evolution has tried to
optimize the enzyme for every substrate (cmp. lock and key theory).
If the optimization was successful I do not see the use of a second
enzyme. And the modification of the amino acid sequence offers
stills enough potential for modifications (e.g. other temperatures,
pH, etc.).

Quote:

Most enzymes are asymmetrical - so by doubling the number of
possible sequences you gain access to twice the number of enzymes.

BTW: If you mix D- and L-amino acids you would get a lot more: an increase
from n^(20) to n^(2*20), n=number of AA in enzyme, assuming 20 AAs.

Quote:

: On the contrary. Some biological toxins (e.g. snake venom) simply
: consist of "mirror" molecules (in this case small chains of amino acids).

? You think mirror life would compete effectively with existing life?
Wouldn't existing organisms eat their lunch?

I know nothing about mirror life, but proteins can be
protected against enzymatic degradation by including some enantiomeric
AAs (also true for some antibiotics IIRC). Now, if this protein is toxic...

Quote:

One point of building mirror life forms would be to reduce the
expense of manufacturing complex mirror proteins - such as enzymes.

You assume that building mirror life can be achieved at no cost?

Sorry, but I still cannot see any practical value in "mirror life",
of course, except winning the Nobel Prize. ;-)

Regards,
Oliver

Tim Tyler

Posted: Tue Sep 23, 2003 6:14 am

Guest

Oliver 'Ojo' Bedford <acp29@campfire.rrz.uni-koeln.de> wrote:
: Tim Tyler <tim@tt1.org> writes:

[Mirror-image life]

:> The expected application of mirror enzymes would be to increase the
:> range of possible enzymes that have medical applications in *ordinary*
:> living organisms.

: Every enzyme acts as catalysator. It makes a certain chemical reaction
: under physiological conditions possible. Evolution has tried to
: optimize the enzyme for every substrate (cmp. lock and key theory).
: If the optimization was successful I do not see the use of a second
: enzyme.

There would be none. The proposed application was to help create
new enzymes with medicinal functions - not improve on existing
perfect enzymes.

There may be other applications. Food that can't be metabolised -
and theraputic viruses which can deliver drugs and equipment - but
whose DNA is guaranteed to be inactive after entry to host cells are
ideas that spring to mind.

:> Most enzymes are asymmetrical - so by doubling the number of
:> possible sequences you gain access to twice the number of enzymes.

: BTW: If you mix D- and L-amino acids you would get a lot more: an increase
: from n^(20) to n^(2*20), n=number of AA in enzyme, assuming 20 AAs.

Indeed. However creating "mirror life" seems somewhat tractable - while
creating a new sort of living organism with a new genetic code capable
of synthesizing arbitrary sequences of both D- and L- amino acids would
require a complete redesign - and would probably represent a *lot* more
work.

:> One point of building mirror life forms would be to reduce the
:> expense of manufacturing complex mirror proteins - such as enzymes.

: You assume that building mirror life can be achieved at no cost?

No.

However the cost of developing such life forms is mostly a one-off R&D
cost.

One it has been done the technology can be preserved at minimal expense
- by supplying air, sunlight - and a few basic resources.

*Maybe* it will wind up being cheaper to produce mirror-enzymes from a
machine.

However there are probably some cost advantages to continuing using
self-replicating factories that expand to take advantage of the
supplied nutrient resources.
--
__________
|im |yler http://timtyler.org/ tim@tt1.org

Oliver 'Ojo' Bedford

Posted: Tue Sep 23, 2003 3:28 pm

Guest

Tim Tyler <tim@tt1.org> writes:

Quote:

The proposed application was to help create
new enzymes with medicinal functions - not improve on existing
perfect enzymes.

But you still have to intervene in the biochemical pathways with
their non-mirror substrates.

Quote:

There may be other applications. Food that can't be metabolised -

You mean like Olestra(tm)? I remember something about leakage and
diarrhea, brrr.

Quote:

and theraputic viruses which can deliver drugs and equipment - but
whose DNA is guaranteed to be inactive after entry to host cells are
ideas that spring to mind.

That cannot possibly work. The virus has to speak the same
language as the host organism. Its DNA (or RNA after going through
the reverse transkriptase) has to be incorporated into the host`s
genome. Then the virus DNA is read by the cells protein synthesizing
machinery. Viruses _are_ a inherently dangerous thing. I remember
some reports about major side-effects of their therapeutic use. This
problem would not be smaller when using mirror viruses.

Quote:

However the cost of developing such life forms is mostly a one-off R&D
cost.

Looking at the costs of developing a drug, it seems
unprobable to me that even a large pharmaceutical company could
afford such a project.

Sorry, if I sound merely destructive.

Regards,
Oliver

Christopher Specker

Posted: Tue Sep 23, 2003 9:40 pm

Guest

Oliver 'Ojo' Bedford wrote:

Quote:

BTW: If you mix D- and L-amino acids you would get a lot more: an increase
from n^(20) to n^(2*20), n=number of AA in enzyme, assuming 20 AAs.

Check your math. The change would be from 20^N to (2*20)^N.

Tim Tyler

Posted: Wed Sep 24, 2003 10:22 am

Guest

Oliver 'Ojo' Bedford <acp29@campfire.rrz.uni-koeln.de> wrote:
: Tim Tyler <tim@tt1.org> writes:

:> The proposed application was to help create new enzymes with medicinal
:> functions - not improve on existing perfect enzymes.

: But you still have to intervene in the biochemical pathways with
: their non-mirror substrates.

Of course. But the ability of enzymes to catalyse reactions and
perform useful tasks depends on the shapes of the resulting folded
proteins. You may be able to make the shape you are seeking better
if you have twice the number of candidates.

:> and theraputic viruses which can deliver drugs and equipment - but
:> whose DNA is guaranteed to be inactive after entry to host cells are
:> ideas that spring to mind.

: That cannot possibly work. The virus has to speak the same
: language as the host organism. Its DNA (or RNA after going through
: the reverse transkriptase) has to be incorporated into the host`s
: genome. Then the virus DNA is read by the cells protein synthesizing
: machinery.

The mirror virus would be cultivated in mirror cells - where it's genome
matches the handedness of the cells that are reproducing it. Those
cells would then be filtered off and the remaining virus would be
injected into the patient's bloodstream.

The reason for using the mirror form is that the virus genome is
much less likely to do any damage inside the host - since all
the transcription machinery that can read it is left behind.

All it can do is deliver the compounds that were present in the
virus to whatever cell-types the virus targets. It can't
hijack host cells to make more of itself in the host, take
over their DNA synthesis equipment or get accidentally
spliced into their genome.

: Viruses _are_ a inherently dangerous thing. I remember
: some reports about major side-effects of their therapeutic use.
: This problem would not be smaller when using mirror viruses.

We /will/ see theraputic viruses, though.

The mirror forms would almost certainly be a lot safer - since they
don't reproduce in the host. On the other hand they would be a lot
more limited in what they can do.

:> However the cost of developing such life forms is mostly a
:> one-off R&D cost.

: Looking at the costs of developing a drug, it seems
: unprobable to me that even a large pharmaceutical company
: could afford such a project.

I don't think the project is very practical today either -
technically or financially.

Costs will fall, though. Mirror life may happen someday.

Mirrors offer useful feedback - they show you from another angle Wink

--
__________
|im |yler http://timtyler.org/ tim@tt1.org

Bob

Posted: Wed Sep 24, 2003 4:31 pm

Guest

On 23 Sep 2003 12:14:03 GMT, Tim Tyler <tim@tt1.org> wrote:

Quote:

Oliver 'Ojo' Bedford <acp29@campfire.rrz.uni-koeln.de> wrote:
: Tim Tyler <tim@tt1.org> writes:

[Mirror-image life]

This is something of a generic reply/post, based on reading several
msgs in this thread. There are multiple issues here, and they are at
least "fun".

When you say mirror bacteria, I assume you mean bacteria in which
_all_ chiral molecules are the enantiomers of those found ordinarily.
That is, the bacteria are truly and completely mirror images. If that
is not correct, please clarify.

Then there are two broad questions... how one would get such mirror
bacteria, and what use they (or their molecules might be).

How would you imagine making such bacteria? Seems to me it would
require essentially a repeat of the origin of life -- and would be
unimaginably difficult. Of course, we at least can list the molecular
parts list, but making those parts and making a self-sustaining system
from them would seem to be beyond us. Do you see a way to bootstrap
this, or ??

As to possible uses...

enzymes? Can you give an example of why you think such an enzyme would
be of some value?

undigestible food. Well, ok, sort of. We have olestra and we have
cellulose. Hm, maybe we should eat more plastic.

Note that fat is not chiral, so mirror bacteria would have the same
fats as normal organism (for the most part). Thus "mirror fat" would
be normally digestible.

An interesting point under this use is that Nature would probably
quickly figure out how to use the proteins. I haven't looked up any
data, but I suspect some proteases/amidases are sufficiently
non-specific to hydrolyze mirror-proteins -- and such activity would
rapidly improve (by usual evolution). Further, amino acid racemases
are already around, and presumably could become part of normal
metabolism if "needed".

Therapeutic viruses. They would still be antigenic. Beyond that, what
advantage would they have over traditional ways of inactivating a
virus? A disadvantage may be that the inactivation is "complete"; the
virus would be "totally" incapable of functioning in the (say) human
host - unless one adds back specific functions. It is actually more
complicated (e.g., smallpox virus carries its own RNA polymerase, if I
recall). But the point is that one would need to think out very
carefully what the pros and cons would be in any specific cases.
Certainly it is hard to generalize.

bob

Tim Tyler

Posted: Fri Sep 26, 2003 6:58 am

Guest

Bob <xyzbbruner@uclink4.berkeley.edu> wrote:

[Mirror-image life]

: When you say mirror bacteria, I assume you mean bacteria in which
: _all_ chiral molecules are the enantiomers of those found ordinarily.
: That is, the bacteria are truly and completely mirror images. [yes]

: Then there are two broad questions... how one would get such mirror
: bacteria, and what use they (or their molecules might be).

: How would you imagine making such bacteria? Seems to me it would
: require essentially a repeat of the origin of life -- and would be
: unimaginably difficult. Of course, we at least can list the molecular
: parts list, but making those parts and making a self-sustaining system
: from them would seem to be beyond us. Do you see a way to bootstrap
: this, or ??

This newsgroup is concerned with making microscopic self-replicating
devices.

It seems likely that we are placed reasonably well to perform this task.
We may not have the parallelism of the pre-biotic oceans - but we /do/
have technological assistance.

In the case of mirror life, we also have a blueprint - and a tested,
working design ;-)

: As to possible uses...

: enzymes? Can you give an example of why you think such an enzyme would
: be of some value?

Through having a useful shape not attainable with a non-mirror enzyme.

: undigestible food. Well, ok, sort of. We have olestra and we have
: cellulose. Hm, maybe we should eat more plastic.

The idea would be to have a similar taste and texture - but be less
likely to be assimilated.

: An interesting point under this use is that Nature would probably
: quickly figure out how to use the proteins. I haven't looked up any
: data, but I suspect some proteases/amidases are sufficiently
: non-specific to hydrolyze mirror-proteins -- and such activity would
: rapidly improve (by usual evolution). [...]

If these subsances became common maybe bacteria that could
digest them would too.

Also, such substances may not be safe. It seems probable that there
would be some safety issues with eating much mirror food.

If they are not safe then an alternative application might be as
appetising poisons. Still - we are probably not short of those ;-)

: Therapeutic viruses. They would still be antigenic. Beyond that, what
: advantage would they have over traditional ways of inactivating a
: virus? [...]

I'm not sure which methods you refer to.

Are there ones that produce a viral delivery system with DNA that
can't do damage once inside the host?

What other uses are there?

Mirror proteins may have industrial applications - probably in
combination with the proteins they mirror.

To illustrate how mirrored components can be useful when
constructing complex machinery, here are two examples:

* The threads on my juicer gears are mirror images:
http://timtyler.org/juicer/graphics/just_gears.jpg

* Similarly, the thread on my left bicycle pedal has the opposite
handedness to the one on my right bicycle pedal.

I reckon if this technology was available, it would find niches to fill.
--
__________
|im |yler http://timtyler.org/ tim@tt1.org

Bob

Posted: Mon Sep 29, 2003 8:23 am

Guest

On 26 Sep 2003 12:58:08 GMT, Tim Tyler <tim@tt1.org> wrote:

Quote:

But we still need to define the task. At this point, we do not know
how to _make_ a cell -- mirror or otherwise (though maybe we are
getting close).

To make a mirror cell requires making a cell, and making all the
special mirror components that are needed -- which must be a few
hundred proteins plus ???

I am willing to accept the technological assistance, or even to do it
as a gedanken expt. But defining it is still needed, and that is not
trivial or obvious. But it is interesting.

Quote:

In the case of mirror life, we also have a blueprint - and a tested,
working design ;-)

agree, but see above. We don't know how to get from "scratch" to self
replicating.

Quote:

: As to possible uses...

: enzymes? Can you give an example of why you think such an enzyme would
: be of some value?

Through having a useful shape not attainable with a non-mirror enzyme.

You are evading the Q! I persist b/c it is not clear what of any
interest would become accessible. Given the incredible difficulty of
embarking on this approach, it would be nice to have a motivation
beyond "basic research". At least in terms of medical applications of
the enzymes, seems unlikely that a mirror enzyme would open up useful
options. I am not saying "no", but I am being somewhat skeptical, and
I am looking for something specific enough to define a project.

Quote:

: undigestible food. Well, ok, sort of. We have olestra and we have
: cellulose. Hm, maybe we should eat more plastic.

The idea would be to have a similar taste and texture - but be less
likely to be assimilated.

The Q of taste (and odor) is interesting. I am told that L-glucose has
the same taste as D-glucose. It is not obvious that it should be so,
and presumably the taste/odor relationship of enantiomers varies.

Quote:

: An interesting point under this use is that Nature would probably
: quickly figure out how to use the proteins. I haven't looked up any
: data, but I suspect some proteases/amidases are sufficiently
: non-specific to hydrolyze mirror-proteins -- and such activity would
: rapidly improve (by usual evolution). [...]

If these subsances became common maybe bacteria that could
digest them would too.

Also, such substances may not be safe. It seems probable that there
would be some safety issues with eating much mirror food.

There would certainly be issues of _perception_ of safety! If the
uneducated consumer doesn't understand current so-called GMO, the
prospect here would be grim.

By the way... commentary on this goes back a ways. Alice remarked
"Perhaps looking-glass milk isn't good to drink" (Thru the Looking
Glass, Ch 1). And that was before stereoisomerism was understood!

Quote:

If they are not safe then an alternative application might be as
appetising poisons. Still - we are probably not short of those ;-)

: Therapeutic viruses. They would still be antigenic. Beyond that, what
: advantage would they have over traditional ways of inactivating a
: virus? [...]

I'm not sure which methods you refer to.

Viruses used for gene delivery are modified to remove all harmful
genes. For AAV (adeno-associated virus), which has no harmful effects,
no specific change is needed.

Occurs to me that there is another hurdle here. A key reason to use
viruses is that they are efficient at delivering things to inside the
cell. But that involves a recognition of the cell by the virus. I
believe (but am not sure) that all the viruses used or gene delivery
use a specific uptake system; making a mirror virus would defeat that.
There may be ways around that, but it would be another issue to
address.

Viruses used for gene delivery fall into two broad categories, those
that lead to the new gene being integrated into the host genome, and
those that merely deposit it in the cell. For the former category, one
would need to think through the implication of using a mirror virus:
what viral DNA sequences and/or functions are needed.

Of course, using a mirror virus would open up new options. But you
would need to consider the problems the new approach would create.

Quote:

Are there ones that produce a viral delivery system with DNA that
can't do damage once inside the host?

see above; AAV is probably the best natural example.

Someone else, in this thread I think, suggested that viruses are
inherently bad or harmful. No, not at all. But there is an
observational bias. Because viruses are so small, we tend to observe
them only when they do something, and often that is something bad.

Quote:

What other uses are there?

Mirror proteins may have industrial applications - probably in
combination with the proteins they mirror.

To illustrate how mirrored components can be useful when
constructing complex machinery, here are two examples:

* The threads on my juicer gears are mirror images:
http://timtyler.org/juicer/graphics/just_gears.jpg

* Similarly, the thread on my left bicycle pedal has the opposite
handedness to the one on my right bicycle pedal.

really? I knew that was so on cars, but I did not know it was
implemented on bicycles.

Quote:

I reckon if this technology was available, it would find niches to fill.

Yes, yes.

My concern is with the difficulty of making it available at the start
(and more specifically of whether we can even define what that
requires). Obviously as basic research tools they would be delightful.

I am somewhat concerned about any applications that involve people
(food, medical, etc), which is what we have mainly discussed above.

Maybe we will find mirror life on Mars. :-)

bob

Oliver 'Ojo' Bedford

Posted: Tue Sep 30, 2003 10:41 am

Guest

Bob <xyzbbruner@uclink4.berkeley.edu> writes:

Quote:

Someone else, in this thread I think, suggested that viruses are
inherently bad or harmful. No, not at all. But there is an
observational bias. Because viruses are so small, we tend to observe
them only when they do something, and often that is something bad.

What I did suggest was that viruses are inherently dangerous.
Their therapeutical use is associated with a risk. The main
problem here is the time-scale, long-term effects need also a long
time to be discovered. So, before their use as genetic vectors becomes
widespread a thorough risk/benefit assessment should be made.
Same applies for "mirror" life.

IMHO (based on newspaper articles and not acquired first-hand)
viral gene therapy in general is not a good thing.

Oliver

Tim Tyler

Posted: Tue Sep 30, 2003 8:39 pm

Guest

Bob <xyzbbruner@uclink4.berkeley.edu> wrote:
: On 26 Sep 2003 12:58:08 GMT, Tim Tyler <tim@tt1.org> wrote:
:>Bob <xyzbbruner@uclink4.berkeley.edu> wrote:

[snip]

:>This newsgroup is concerned with making microscopic self-replicating
:>devices.

:>In the case of mirror life, we also have a blueprint - and a tested,
:>working design ;-)

: agree, but see above. We don't know how to get from "scratch" to self
: replicating.

Yes - we should certainly master making ordinary cells long before trying
to make "mirror" ones ;-)

:>: As to possible uses...
:>
:>: enzymes? Can you give an example of why you think such an enzyme would
:>: be of some value?
:>
:>Through having a useful shape not attainable with a non-mirror enzyme.

: You are evading the Q! I persist b/c it is not clear what of any
: interest would become accessible. [...]

Nor to me.

ISTM that there are various possibilities - ranging from:

* Mirror enzymes don't add much - all the useful catalytic shapes are
fairly easily reachable anyway, using normal proteins - mirror enzymes
are about as effective - or perhaps even systematically less effective;

.....to:

* Some particular mirror enzymes happen to be /much/ better at their
task than any normal enzymes that have been found. If this happens
with something like a DNA synthesis enzyme, then a real application
arises.

: A key reason to use viruses is that they are efficient at delivering
: things to inside the cell. But that involves a recognition of the cell
: by the virus. I believe (but am not sure) that all the viruses used or
: gene delivery use a specific uptake system; making a mirror virus would
: defeat that.

If the virus targets a cell using a chiral protein discriminator,
then that virus is probably not worth bothering using in this area.

: Viruses used for gene delivery fall into two broad categories, those
: that lead to the new gene being integrated into the host genome, and
: those that merely deposit it in the cell. For the former category, one
: would need to think through the implication of using a mirror virus:
: what viral DNA sequences and/or functions are needed.

I don't see gene delivery as being very realistic - due to everything
being backwards. The idea would be to deliver particular compounds or
drugs - without the genes that made them causing any danger in the cell.

:>To illustrate how mirrored components can be useful when
:>constructing complex machinery, here are two examples:
:>
:>* The threads on my juicer gears are mirror images:
:> http://timtyler.org/juicer/graphics/just_gears.jpg
:>
:>* Similarly, the thread on my left bicycle pedal has the opposite
:> handedness to the one on my right bicycle pedal.

: really? I knew that was so on cars, but I did not know it was
: implemented on bicycles.

The pedals have opposite handed threads - so they don't unscrew
themselves as you go along.

:>I reckon if this technology was available, it would find niches to fill.

: Yes, yes.

: My concern is with the difficulty of making it available at the start

[...]

It /is/ a bit of an esoteric idea. I don't know if it will be seen as
being useful enough to embark on.

Presumably it will happen /eventually/ in the far future anyway - as an
academic research project to examine the viability of the system.

I suspect there probably are industrial applictions that will mean the
project is undertaken before then. I guess we'll have to wait and see.
--
__________
|im |yler http://timtyler.org/ tim@tt1lock.org Remove lock to reply.

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