In article <jcherwon.14.0010CD8A at dres.dnd.ca>,
John Cherwonogrodzky <jcherwon at dres.dnd.ca> wrote:
>Dear Colleagues:
> The subject of prions has come up and I think it is a very important
>topic. If you look at the history of disease outbreaks in the 20th century,
>there has been an intense see-saw between these and humans. (as G.P. Youmans
>et al. said in his book, 1975, "Although man can build a better mouse tra,
>nayure always seems to build a better mouse")
>
[snip]
>>Prions are not my expertise, but what I've read in the past implies that
>thereare 2 schools of thought. One is that prions are infectious protein
>particles, not having associated DNA/RNA (evidence is sensitivity to
>proteases, insensitivity to nucleases), the other is prions are a name for
>something no-one has a clue about.
Stan Prusiner gave a talk on prions here at Cal back in September, and he gave
pretty convincing evidence that at least one prion disease (mouse scrapie) is
truly caused by an infectious protein. His lab has identified and purified
the protein, which is a normal cellular factor. The only difference between
the normal and "scrapie" forms is one of protein conformation. The "scrapie"
form is able to catalyze the change in conformation, resulting in a sort of
"replication". There were also some interesting data about different "strains"
of prions, all of which have identical sequences but different pathologies and
host preferences.
BioKen
--
Ken Frauwirth (MiSTie #33025) _ _
frauwirt at mendel.berkeley.edu |_) * |/ (_ |\ |
Dept. of Molec. & Cell Bio. |_) | () |\ (_ | \|
Univ. of Cal., Berkeley Push the button...someone :(
