How about using an anion exchanger after your NTA step ?
Jürgen
......................
Jürgen Bosch
Johns Hopkins Bloomberg School of Public Health
Department of Biochemistry & Molecular Biology
Johns Hopkins Malaria Research Institute
615 North Wolfe Street, W8708
Baltimore, MD 21205
Phone: +1-410-614-4742
Lab: +1-410-614-4894
Fax: +1-410-955-3655
http://web.mac.com/bosch_lab/
On Jan 8, 2010, at 7:41, Sivaraman Padavattan <[log in to unmask]>
wrote:
> Dear all,
> I am trying to express the human protein using bacterial expression
> strain (Rosetta) and purified using Ni-NTA affinity purification.
> The Molecular weight of out protein is 47 kDa. In SDS-PAGE, we have
> seen that 27 kDa contaminant protein co-eluted with our protein even
> at high concentration of Imidazole. In Superose 12 column, these two
> proteins eluted as a single peak and its corresponding molecular
> weight suggestive of partial interaction. By mass mapping we have
> found 27 kDa band is an adenylate kinase. Is there any specific way
> to separate adenylate kinase from our protein?
> Thanks in advance,
>
> Sivaraman Padavattan
>
>
>
|