From: hal@finney.org
Date: Mon Sep 06 1999 - 00:20:08 MDT
Gina Miller, <nanogirl@halcyon.com>, writes:
> *For decades, pharmaceutical companies have struggled to overcome the
> molecular equivalent of the Great Wall of China: the outer membrane of
> cells, which prevents all but the tiniest of proteins from entering. Now
> researchers have slipped a protein that's more than 200 times larger than
> the average drug into the cells of living mice and shown that the protein
> functions.
> http://medicine.wustl.edu/~wumpa/news/dowdyprotein.html
It is interesting to learn that the reason proteins are able to get
into cells is because they are capable of unfolding. Proteins are
long linear molecules which fold up into fuzzy balls or other shapes.
It is when they have their folded-up configurations that they become
biologically active. But apparently it is necessary that they unfold
back into their linear form (or something close to it) in order to pass
through the narrow channels through cell walls. Then the refold once
the get to the other side.
This might pose a problem for a nanotech device which wants to make its
way into the cell. It will not be able to unfold and so will need to
hack its way through the membrane somehow. Perhaps the upcoming book
Nanomedicine will include a chapter on breaking and entering.
> *Cloning gives second chance for bull. A calf has been cloned from a
> 21-year-old celebrity bull, the oldest animal yet reproduced using this
> technology.
> http://news.bbc.co.uk/hi/english/sci/tech/newsid_437000/437391.stm
The old bull was named Chance; his clone, Second Chance. It took 189
tries to get a viable clone; as with Dolly, the procedure still produces
many more failures than successes.
"Professor Westhusin also leads the Missyplicity Project which is
attempting to produce the first cloned dog. The anonymous sponsors of the
project have invested $2.3 million to produce a clone of their pet dog,
Missy, a mixed-breed border collie."
With a pure breed you can get another dog which is much the same in
appearance and temperament, but with a mixed breed it's not so easy
to get one which is similar. So I suppose cloning is the way to go if
you've got a couple million dollars lying around. You could actually
make multiple copies and start your own mini dog breed. This is what was
originally meant by "clone", a set of genetically identical individuals.
Hal
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