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.
It is also possible that the kinetics of association and dissociation
is faster than the retention time - then you'll never see dimeric or
tetrameric peaks. This is because one molecule is and runs as a dimer
for a fraction (depending on the equilibrium constant) of the time,
and a tetramer for the rest. If dimers and tetramers each account for
about half of the protein, you'll see a broad peak with the retention
time of a trimer...
Yours, Frank
--
Die Verwendung von mehreren Ausrufezeichen macht die Aussage nicht
ausrufender sondern ausufernder. [Michael Bauer in dnq]