glycerol to avoid protein precipitation?...
tguettou at newssun
Thu Aug 22 17:56:10 EST 1996
On Tue, 20 Aug 1996, Arioch wrote:
> hey all,
> ...had heard seomwhere that adding glycerol to purified protein
> and then freezing them keeps the breakdown at a minimum and prevents
> protein precipitation (after freeze-thawing from the -20 degrees C).
> has anybody tried this?? i wouold really appreciate any help on
> Arioch (siyer at bmg.bhs.uab.edu)
> Graduate Student ( and Lord of Chaos...)
> Dept. of Biochemistry and Molecular Genetics...
> Milieu of Entropy (a.k.a University of Alabama at Birmingham...)
Glycerol basically prevents proteins from unfolding (there is a paper
from W. Welch et all at UCSF, I think from 1994). This prevents
aggregation and precipitation of your protein as well. Another good thing
is to use Hepes-buffer(if possible), which shows little change in pH when
frozen (a major factor of enzyme inactivation; ref.: Hill and Buckley, Anal
in Biochem., 192(2), 358(1991)). Also adding some salt your protein likes
(NaCl, KCl etc) might be a good thing. Some people also add EDTA, DTT and
non ionic detergents like Tween 20 or Triton-X to prevent aggregation. ,
Hope that helps
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