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Nada, I agree with Tim. One exception I know of was a protein that precipitated upon dialysis and did not crystallize in the presence of imidazole (after only one column). We precipitated the protein from the imidazole solution with PEI (AmSO4 would probably also work), resuspended it in low salt buffer, and purified it by ion exchange and size exclusion. This gave us beautifully diffracting crystals. Tom Huxford. ============================================================================ On Wed, 14 Sep 2005, Tim Gruene wrote: > *** For details on how to be removed from this list visit the *** > *** CCP4 home page http://www.ccp4.ac.uk *** > > > Hallo Nada, > > there are probably many people who made good experience with the presence > of imidazole for crystallisation as there are many with bad experience. > > However, from what you were writing it sounds as though you want to > crystallise the protein straight from the Ni-column. From my experience - > and I dare say most people will agree - it is a good idea to have more > than one or two purification steps. And a side effect of e.g. a size > exclusion column would be that you can conveniently get rid of the > imidazole, and most protein crystallographers I met would probably do > so. > > If, however, your protein likes imidazole or even needs it for solubility, > then obviously you keep the concentration throughout your purification. > > Hope this helps, > > Tim > > -- > Tim Gruene > Institut fuer anorganische Chemie > Tammannstr. 4 > D-37077 Goettingen > > GPG Key ID = A46BEE1A > > > On Wed, 14 Sep 2005, Nada wrote: > > > Hello. > > > > Please I would like to know if someone has had some experience with > > crystallization of protein in solution containing also 1M imidazole. Is it > > necessary to remove it from solution after elution of protein from > > Ni-column? > > > > Thank you > > > > Nada Pavlendova > > > > IMB, Bratislava, Slovakia > > > > >
