I agree (I mean there is a fast equilibrium between the two species) but as
I want to prepare a sample for NMR, I can NOT play too much with pH and
also with salt concentration. By the way, what I observed is that
increasing the amount of NaCl the gel filtration peak move towards the
dimeric form but NMR told us that the dimeric specie seems a molten globule
one, even if the tetramer is well folded. So my problem is to have one
specie (dimer or tetramer) AND well folded AND, at the same time,
omogeneous. Gel filtration seems not good to test omogeneity, maybe either
BN-page is not, I don't know.
Any idea how to move the equilibrium towards a well folded tetramer or
dimer (not using chaotrops)?
thank you for the suggestions
Vale
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