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
