this sort Ni problem happen to me, When I changed the pH of the
flowing-phase to 5.5, my protein start eluting interestingly.
Generally, His-coloums has endurance to pH which is between 11-3, why
do not you try to get it by changing by pH?
Hope that you will find a way to purify your protein easily.
Mehmet Sen
Duncan Clark <junk@[127.0.0.1]> wrote in message news:<ieAThPGuBVEAFAfj@[127.0.0.1]>...
> Historians believe that in newspost <bur0r9$1ckg$1 at gwdu112.gwdg.de> on
> Fri, 23 Jan 2004, Stephan Wenkel <wenkel at mpiz-koeln.mpg.de> penned the
> following literary masterpiece:
> >Thanks for your reply, but stripping the resin with EDTA does also have
> >only a little effect.
>> Then it's not binding by His-Ni interaction, as EDTA removes all the Ni
> of the resin.
>> Hydrophobic interaction? Try 20% Ethylene glycol in buffer.
>> Try 20% ethylene glycol plus a Urea gradient up to say 3M in buffer.
>> Or wild guess.
>> Could it be binding to the chelating bit of the column i.e. You
> initially purify your protein which hangs onto some Ni. You load your
> dialysed protein back on and create a chelated protein via the Ni
> moiety, with a very strong interaction.
>> Duncan
