The Prion Hypothesis

A.Ferszt aferszt at ic.ac.uk
Thu Jan 21 13:36:09 EST 1999


Sturla Molden wrote:
> 
> In bionet.neuroscience shootingstar21 at hotmail.com wrote:
> : How sound is the prion hypothesis by Stanley Prusiner and how exactly does a
> : normal protein change into a shape that can cause disease and distort other
> : normal proteins into the "bad" shape? Also, specifically, what is the
> : experimental evidence for the prion hypothesis and what are the new
> : developments, if any, in the theory and in finding cures for prion diseases?
> 
> In my opinion the prion theory is in violation of the 2nd law of
> thermodynamics. According to the theory, prions grows like
> salt crystals. The entropy of the crystal is lower than
> the entropy of the ions, but crystal growth is driven by evaporation
> of the solvent (water), which provide the entropy increase.
> In the prion case, however, the entropy of the proteins decreases
> spontaneously but this is not accompanied by a parallel
> entropy increase (e.g. from water evaporation). Consequently,
> the theory must be false. That's my opinion.
> 
> Sturla Molden
> 
> 

It is perfectly possible to grow crystals *without* evaporation of the
solvent. Among other factors crystal growth is driven by the
*preference* for the atoms/molecules involved for each other over the
solvent. In the proper environment many proteins spontaneously
aggregate.

The theory is not disproven (which of course is not the same as proving
it).



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