X-Message-Number: 22240 Date: Tue, 22 Jul 2003 18:13:13 -0400 From: Francois <> Subject: Inquiry about prions If I am not mistaken, prions are mishaped versions of normal brain proteins. When they come in contact with their normal versions, they cause them to refold themselves to the prion state, thus triggering a chain reaction that ends with the death of the "infected" individual. The mad cow disease crisis in England, as well as exotic human diseases like Kuru, demonstrate that eating prion contaminated food can spread the disease. However, I don't understand how this is possible. First, most protein based foods are cooked, which denatures proteins. Then, the consumed proteins are digested and broken down to their constituant amino acids. Third, those proteins that escape digestion will no easily go throught the gut's lining and enter the blood stream. And fourth, even if some protein molecules manage to get into the blood, the brain blood barrier will not allow them through. In view of all those obstacles, I find it remarkable that prion based desease can be so easily transmitted. There is obviously some other mecanism at work here and I would very much appreciate it if someone could tell me what it is. Francois ----------------------------------------------------------------- "First they ignore you, then they laugh at you, then they fight you, then you win." Mahatma Gandhi ----------------------------------------------------------------- Rate This Message: http://www.cryonet.org/cgi-bin/rate.cgi?msg=22240