Dimer->monomer->dimer

Frank Fuerst fant.1 at gmx.net
Mon Mar 6 06:05:04 EST 2000


" J. Martinez-Irujo" wrote:
> 
> In fact, it depends on the strength of the interaction. Try to  prepare
> your protein in a solution containing different concentrations (5%, 10%,
> 15%, 20%...) of an organic solvent (methanol, ethanol, acetonitrile...)
> in a suitable buffer at 0-4 oC (dilute 1:1 or  dialyze against this
> buffer). 

You can also try small concentrations of denaturant (urea or guanidin
hydrochloride); a plateau in a denaturation transition is sometimes a
sign for folded monomers.

> Remember that the absolute concentration of the protein affects
> to the monomer-dimer equilibrium, so test several concentrations of your
> protein. 

And remember that some proteins won't form stable monomers! So perhaps
you'll just get aggregated protein, or unfolded monomeric chains.

> You can also follow the process by measuring enzyme activity (a
> 100-fold dilution may be necessary to avoid solvent effects). 

Sometimes even monomers are enzymatically active.

> Good luck.

>From me too, because it is not always possible.

Bye, Frank
-- 
Die Verwendung von mehreren Ausrufezeichen macht die Aussage nicht
ausrufender sondern ausufernder. [Michael Bauer in dnq]




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