pGEX expression problems

[farleyp at HAL.HAHNEMANN.EDU]

The doublet protein may be an E. coli protein (dnaK) that co-purifies with many proteins expressed in pGEX-2T (is your extra band about 70 kDa?) The dnaK
protein runs around 70kDa on SDS-PAGE.  This protein purifies with glutathione-
agarose and I also have it co-purify when I use an immunoaffinity column.  I
understand that many people have had problems cleaving their fusion protein
with thrombin.  Good luck --

Patrick Farley
farleyp at hal.hahnemann.edu