I am experiencing difficulty with reproducing the oligomerization
state of a protein overexpressed and purified from E. coli, from prep
to prep. I have considered increasing the glycerol concentration in
the buffers to promote the dimer state over the monomer state (no
other oligomerization states are detected). The DNA binding protein
is likely not bound with DNA during these later stages of purification
as we have incubated the cell extracts with a cocktail of nucleases.
Does anyone have any suggestions? The buffers already contain 10%
glycerol; is there any reason (that I've not yet thought of) that I
might not want to increase the glycerol concentration further? I'm
ashamed to admit it, but I'm currently uncomfortable with more than
10% simply because I've not seen literature that cited a buffer
containing more than 10%!
Any other suggestions are welcome...