GST contamination of GST fusion protein

Paul J. Phelan via methods%40net.bio.net (by Paul.Phelan from tufts.edu)
Thu Mar 27 18:45:28 EST 2008


To whom it concerns,
This question maybe have been asked before, but I am having trouble 
with separating GST from a preparation of GST-Importin alpha.  I have 
maybe 10-20% GST co-purifying with the fusion protein.  The pI of both 
proteins is the same, so ion exchange chromatography does not separate 
them, and even on a Sephacryl S-100 gel filtration column, the two 
proteins (87 kDa fusion, 27 kDa GST) eluted together.  Does anyone have 
a clever trick to remove GST from a GST fusion prep.?
My next attempt is going to be to try gel filtration again but with 0.3 
M NaCl and maybe some detergent to try to separate the proteins.

Any advice would be greatly appreciated, thanks

Paul Phelan Tufts University Biochemistry Dept. Boston



More information about the Methods mailing list