What are prion diseases?

Question

it'll be better if u can give me a chemical perspective of the disease.

Answer 1

Prion diseases or transmissible spongiform encephalopathies (TSEs) are a family of rare progressive neurodegenerative disorders that affect both humans and animals. They are distinguished by long incubation periods, characteristic spongiform changes associated with neuronal loss, and a failure to induce inflammatory response.

The causative agent of TSEs is believed to be a prion. A prion is an abnormal, transmissible agent that is able to induce abnormal folding of normal cellular prion proteins in the brain, leading to brain damage and the characteristics signs and symptoms of the disease. Prion diseases are usually rapidly progressive and always fatal.

Answer 2

Prions are proteins. There are good prions and bad prions. In a prion disease, some prions are misfolded and when they encounter other proteints, they cause them to become misfolded too.

You can think of these bad prions like the Borg from Star Trek. The Borg, like the prions, assimilate others and make them into Borg.

Of course if you have a protein which had a special prupose and a bad prion comes along and causes it to misfold, it can't do its job any more.

In "mad cow disease", known as vCJD in humans, the bulk of the prion's wrath occures in the brain and the brain literally disintigrates.

Answer 3

Whilst the majority of scientists agree with the prion hypothesis, there is some evidence to show that it is not just an infectious protein; when co infected with short pieces of DNA, the infection progresses quicker, and has a higher death rate. Odd.

Incidently the prion "reproduces" by inducing a conformational change in the target protein. It is assumed that this is by binding. This site is good for information.

http://www-micro.msb.le.ac.uk/

Answer 4

prions are evil little things... they like literally crash through cells. It's malformed proteins that, due to their chemical composition, destroy cells. And, you can't kill them since they're not alive. It may one day be possible to neutralize them, but they are deadly now since they are resistant to proteases, the body's chemicals that break down proteins... They can endure for decades, and people that die of these diseases were usually exposed to multiple doses. The prions just keep circulating until they finally run into the brain cells. Since brain cells do not reproduce, the prions eventually kill that person or animal.

Scientists do not really fully understand how they actually reproduce, but I do know this.. cannibalism is a good way to spread the disease. Human cannibals have this disease, and animals who have been fed dead parts of other like animals can get prions. This is what caused mad cow disease.

Wikipedia says that they are... proteinaceous infectious particle that lacks nucleic acid (by analogy to virion) — is a type of infectious agent made only of protein. Prions are believed to infect and propagate by refolding abnormally into a structure which is able to convert normal molecules of the protein into the abnormally structured form. However, the term in itself does not preclude other mechanisms of transmission. rest of article here....

http://en.wikipedia.org/wiki/Prions

some of the diseases are Kuru, Creutzfeld-Jacobs (mad cow), and scrapie (mad sheep and goat).

I lived in Italy for 3 years and upon my return I was no longer able to give blood to the Red Cross. I was told that I had been exposed to prions.... Mad Cow disease...

Answer 5

how about mad cow disease....or, the human variant, Creutzfeldt-Jakob Disease? Kuru? (a disease canibals get)
I dont have the time or inclination to explain (almost bed time) so I hope this will help....
http://www.cdc.gov/ncidod/dvrd/prions/
http://www.sciencemag.org/feature/data/prusiner/245.dtl