How animals in the hydrothermal vent can live with the high temperature.
jsilver at merseia.fsnet.co.uk
Sat Mar 30 08:29:28 EST 2002
In message <3ca52ae3.873801 at news.earthlink.net>, Davin C. Enigl
<enigl at aol.com> writes
>On Fri, 29 Mar 2002 15:10:21 -0600, "Paul F. Dietz"
><dietz at interaccess.com> wrote:
>>Perhaps they get converted to a carbonized nanolump that
>>has a similar shape and can initiate the same conformational
>>chain reaction in the affected proteins.
>I don't think your nanolumps would be composed of the organic prions
>themselves, because the lumps would have decomposed beta sheets,
>haveins sid that . . . a variation on your "nanolump theory" was one
>of the possibilities proposed by Paul Brown et al. in the paper New
>studies on the heat resistance of hamster-adapted scrapie agent:
>Threshold survival after ashing at 600°C suggests an inorganic
>template of replication -- Paul Brown, Edward H. Rau, Bruce K.
>Johnson, Alfred E. Bacote, Clarence J. Gibbs Jr., and D. Carleton
>Gajdusek. (I already posted the web site and in reference to Jonathan
>This has some spectacular possibilities for inorganic self-replication
>of organic biomolecules (by inorganic self-assembly):
>1) We have Prions in a brain tissue matrix.
>2) We subject this to gradual heating up to 600C.
>3) By heating, a lot of freely moving carbon atoms are created by
>partial destruction of the tissues and prions remain protected from
>destruction by that carbon. This protection is already shown to take
>place by Taylor (1991) in autoclaved prion material.
>4) The prions are coated with carbon. This would not be biologically
>active because the 3-D size would be larger than the original.
>However, (at least) partial 2-D (and maybe 3-D) carbon casts might
>still be made of the bio-active area of the prion, i.e. forms of the
>"real" bio-prions. (This is going to be a fossilization process.)
>5) The casts might release the bio-prions and the bio-prions then get
>fully denatured. But this leave the carbon casts intact.
>6) An inorganic mineralization could take place as in crystal
>formation on a molecular level making an exact ( or good enough) copy
>of the organic biomolecule (prion in this case).
>7) That inorganic positive (probably not 3-D, but, 2-D) cast could
>then be a bio-mimic and could act as a catalyst on the PrP precursor
>causing the CJD/BSE/TSE.
>This inorganic-mimic would be more heat resistant than the orininal
>organic bio-prion. Yet, it does not survive 1000C for long.
>Brown, et al. says that total destruction of prion infectivity in a
>bio-medical trash sterilization chamber (even at the exit temperature
>of 1000C), can not be assued at this point.
>As far as I know no microorganism (actually, I mean, spores) has
>survived beyond 370C for any prolonged length of time and remained
>viable. Unfortunately, I do not know the actual D-values involved.
>But the above "inorganic nanolump" would leave open the possibility
>for a biologically-active inorganic form of prion based on castings of
>prion organic molecules. The inorganic nanolumps could exist.
>Could more complexed inorganic-lifeforms exist or be constructed by us
>based on organic castings? This is a nanotechnology production method
>in materials science already by Burkett and Davis (1995), and Burkett
>and Simms (1996).
I suspect it will go the other way - inorganic casts have great
stability but organic molecules have much more flexibility in the ways
you can put them together.
There's a theory that the original substrate for the evolution of life
was inorganic (Cairns ??) and there's an SF story by Hal Clement in
which zeolite is used as the template for coding artificial life-forms.
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