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Author Topic: How do prions inflict their structure on other proteins?  (Read 1753 times)

Offline thedoc

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Triant Elef asked the Naked Scientists:
   
What gives a prion the ability to exert a "bad influence" on well structured proteins? Why is the reverse impossible, that is, normal proteins pressing prions to resume their correct structure? Thank you.

What do you think?
« Last Edit: 13/12/2013 11:30:01 by _system »


 

Offline evan_au

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Re: How do prions inflict their structure on other proteins?
« Reply #1 on: 15/12/2013 10:18:46 »
Chemicals with a simple structure will form dense, stable crystals, when triggered by a "seed".

Biologists like to study proteins using X-Ray crystallography, as this gives a good understanding of the structure of the protein - but many proteins have a complex structure that does not crystallise easily.

However, people with certain allelles of the PRNP gene form stable needle-like crystals of the prion protein - either spontaneously, or when they consume food containing misfolded prion protein as a seed.

These crystals recruit the normal protein to the ends of the needle, where it misfolds and adds to the ends of the needle as parallel protein "Beta sheets". As these needles grow, they cause cell death. These needles can break, resulting in an exponential growth of the misfolded protein, once infection starts.

Due to the stability of these crystal structures, the cell cannot break them down - and indeed normal sterilisation techniques such as autoclaves have limited success - treatment with bleach or sodium hydroxide is recommended.

The details of Prion disease are still debated. However, there are a number of human diseases involving abnormal crystallisation of proteins - either as a primary cause, or as a side-effect of the disease.
 

Offline evan_au

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Re: How do prions inflict their structure on other proteins?
« Reply #2 on: 23/02/2014 05:49:11 »
Prions have been linked to formation of long-term memories in the brain in animal studies.
 

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Re: How do prions inflict their structure on other proteins?
« Reply #2 on: 23/02/2014 05:49:11 »

 

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