In message <3ca62a11.27924152 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:
>>>"Davin C. Enigl" wrote:
>>>>> Yet, I read prions survive 1000C for 1 hour, and higher temperatures
>>> that would normaly "ash" naked amino acids.
>>>>I seriously doubt prions survive unchanged for 1 hour at 1000 C.
>>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.
>>>> Paul
>>Well, never-the-less the I read article claimed the prion was still
>caused BSE, so I was not affected very much if at all -- certainly not
>to the point where anyone would claim they were denatured.
>>This "survival after ashing" was also stated as a fact, by Paul
>Brown's research at the US National Institutes of Health.
>>As you know, catalysts like prions must be quite specific via the
>"lock and key" theory. Therefore, I can not see how a break in say,
>the beta sheet conformation could still cause disease. The alpha
>helical form (normal) is easily denatured however.
>>Also, sterilization by heat alone is not enough to make me comfortable
>. . . we add a 1.0 M NaOH flood over the item to be sterilized and
>then autoclaving at 132 C for 5 hours is our current standard, --
>UCSF recommended this some years ago. I am not sure what F sub-zero
>at 132C that works out to for 1000C for 1 hour dry heat, -- but the
>NaOH water solution certainly must lower the D-value more than
>autoclaving alone.
>>This has significance for extreme-ophile research and
>Astromicrobiology theory.
If you're thinking of the paper I think you are (it's on-line at the
PNAS web site) they _didn't_ find infectivity at 1000C but they did at
600C. Their theory is that some inorganic matrix survives at that
temperature but not at 1000C.
BTW, isn't 2.0 M NaOH now recommended?
