Purifying an ERM protein: is Ni-NTA compatable w/ 2M NaI?

Jonathan Kurtis, MD/PhD jkurtis at mail.med.upenn.edu
Wed Mar 31 23:45:01 EST 1999

Thanks for your help. I'm binding and washing under native conditions (3x
PBS, ph 8) and eluting with 50 mM Immidazole. I was hoping not to denature
and have to refold my protein. If the NaI does not work, I'll try urea.

Thanks again,


> NaI is chaotropic.  Although I couldn't say for certain that you can use
> NaI, I routinely purify His-tagged proteins on nickel columns using
> solutions with either 8M urea or 6M GuHCl, both strongly shaotropic agents. 
> The problem with using NaI might be if the iodide reduced the metal ion (I
> don't know if this will happen or not, just something that you might want to
> watch out for).
>     Anyway, if you bind your His-tagged protein in 6 M GuHCl and include 8M
> urea in your wash and elution buffers, I would be surprised if your binding
> protein came along for the ride.
> Warren Gallin
> Department of Biological Sciences
> University of Alberta
> Edmonton,  Alberta     T6G 2E9
> Canada
> wgallin at gpu.srv.ualberta.ca

Jonathan Kurtis, M.D./Ph.D.
Department of Pathology and Laboratory Medicine
6th Floor, Founders
Hospital of the University of Pennsylvania
3400 Spruce Street
Philadelphia, PA  19104-6523

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