PS In fact, the protein I mentioned, was not his-tagged, and first purification
step I used (after streptomycin sulphate precipitation of DNA and dialysis) was
on DEAE-sepharose at pH 8. In this, the protein surprisingly bound, I would
guess via bound nucleic acid contaminants, so in effect the
Hola Careina,
filtering won't help much against aggregation, it just removes the larger
aggregates, but the protein may still form small aggregates that pass the
filter.
and remember the pI from the sequence is only an estimation and may or may not
be close to the real pI, which can only be me
Dear ccp4 bulletin board
Sorry for off topic question. I'm working with a protein with pI 9.5 and yet it
will not bind to a cm sepharose column when equilibrated at pH 6.5. I have
removed all salt from the buffer but it still will not bind. I wonder if anyone
has suggestions as to why this coul