What are Prions?

Question

It's for science any1 help???

Answer 1

hope this helps...

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

Answer 2

prions are misfolded proteins.

Proteins have a definite 3 dimensional structure. And their structure has lot to do with their function.
A protein is produced as a linear chain and gets folded into a ball like 3 D structure.

As u know proteins perform many vital funtions in the body, like enzymes are proteins, haemoglobin is protein. So imagine these proteins were folded not into their actual 3D shape but some other shape, then they will loose their function and also they will gain some other harmful function that is dictated by this newly misfolded structure.

Luckily haemoglobin and others have not been shown to misfold TILL NOW.

but a variety of other neural diseases like mad cow's disease is due to prions

Answer 3

Prions are another infectious particles like viruses which unlike viruses don't have any genetic material. They are simply protein molecules. There mode of infection was a great puzzle for scientists as it lacks the genetic material but now it has been proved that the proteins which they contain have a tendency to change the nature of other proteins (Due to some enzymatic actions). When prions come in contact with the proper host cell, their protein changes the nature of host cell proteins thus making it either useless or harmfull to the cell.
Prions attack to the proteome of the organism unlike viruses, which attack to the genome of the organism.

Answer 4

A prion (IPA: [ˈpriːɒn][1] listen (help·info)) — short for proteinaceous infectious particle (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, and they are generally quite resistant to denaturation by protease, heat, radiation, and formalin treatments[2], although potency or infectivity can be reduced. The term does not, however, a priori preclude other mechanisms of transmission.

The term prion has also come to refer to the specific protein (or gene) associated with and generally believed to be responsible for transmissible spongiform encephalopathies (TSEs), the first identified infectious protein. These include scrapie (a disease of sheep), chronic wasting disease, (in deer and elk), variant Creutzfeldt-Jakob disease (vCJD), and bovine spongiform encephalopathy (BSE or mad cow disease), all caused by homologous proteins in different species.[3] It should be noted that the same gene is responsible for spongiform encephalopathies which are not known to be transmissible, as well as some non-neurological diseases. Some require a mutation for transmission to occur, and there are respective mutations which can prevent transmission for most of the TSEs. A non-disease function of the prion gene is not known but is an area of considerable active research.

All of these diseases affect the structure of the brain or other neural tissue, and all are untreatable and fatal. However, a vaccine has been developed in mice that may provide insight into providing a vaccine in humans to resist prion infections. (see external links below, Science Daily article on vaccine).

Proteins showing prion behaviour are also found in some fungi. Some fungal prions may not be associated with any disease; it is unknown whether these prions represent an evolutionary advantage for their hosts. All known prions are believed to infect and propagate by formation of an amyloid fold, in which the protein polymerizes into a fiber with a core consisting of tightly packed beta sheets. Other mechanisms may exist in yet undiscovered infectious protein particles.

You could get more information from the link below...

Answer 5

last year i had my final presentation on prions.
they are proteins gone bad if you know what i mean!!!

prions are toxic proteins which travel the blood and mainly settle in the brain causing fatal diseases. the most famous of prion disease can be the mad caw disease (or new variant cjd). unfortunately prion disease are still uncurable and it is belived that there might be some advances in treating them soon using some advanced methods. i would suggest you read about prions in wikipedia as there is quite details, or if u want i can email you my presentation from last year, its on prions,their chemistry, morphology and all diseases they cause.

Answer 6

proteinaceous infectious particle (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, and they are generally quite resistant to denaturation by protease, heat, radiation, and formalin treatments[2], although potency or infectivity can be reduced. The term does not, however, a priori preclude other mechanisms of transmission. :-)

Answer 7

Prions are proteins that are misfolded in a way that cause them to damage, obstruct or destroy nearby tissue or cellular functioning.

Proteins are big big molecules, to fit them inside cells they have to be folded up, they must be folded up just so otherwise the cellular machinery won't be able to deal with them properly and use them for whatver purpose they are meant for.

Answer 8

a prion is essentially an "infectious" protein. It binds to other proteins resulting in them becoming prion-like

Answer 9

A microscopic protein particle similar to a virus but lacking nucleic acid, thought to be the infectious agent responsible for scrapie and certain other degenerative diseases of the nervous system.
A microscopic protein particle similar to a virus but lacking nucleic acid, thought to be the infectious agent responsible for scrapie and certain other degenerative diseases of the nervous system.

pr(oteinaceous) + i(nfectious) + -on 1

Answer 10

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