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 <[email protected]>
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
