Valeria Maida wrote:
> Hallo everybody!
> I'm working on a protein that likely forms tetramers and dimers in
> equilibrium. The monomer molecular mass is around 12. I would like to move
> the equilibrium towards the dimers or tetramer but I have many difficult by
> gel filtration to obtain the separation of the two species: tipically on a
> Superose12 the sample elute in the trimer position instead of having two
> defined peaks.
For this protein I would try a Superdex 75 filtration column; it gives much
better resolution than Superose 12 (try several sal concentrations). Bad news
are that this column is very expensive, and sometimes you may need to use two
of them in tandem (for example Superdex 75 + Superdex 200), specially when
separating dimer/monomer species.
If native electrophoresis works well in your hands, please send a mail to this
newsgroup, it could help many people...
--
Juan J. Martinez Irujo
Departamento de Bioquimica
Universidad de Navarra
Pamplona, Spain.
