Expression of GST fusion
bheymann at bragg.bio.purdue.edu
Fri Mar 8 10:34:59 EST 1996
This issue has come up again and again many times in this newsgroup.
After my experiences and these anecdotes about apparent degradation of GST
fusions, I've become convinced that it is not degradation, but a
transcriptional problem. Somehow there is a transcriptional truncation
signal at the end of the GST gene and with fusion proteins you get both
the full length protein and a truncated product of the size of GST. The
other sad part of the story is that the GSH affinity columns are very
selective and you seldomly get any contaminants (compared to the His-tags,
Strep-tags and thioredoxin fusions I've tried). I think the only viable
solution is to try different expression strains and see if you can get rid
of the truncation product (unfortunately I don't have any specific strains
in mind). I hope this helps. Good luck!
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