I need a solution for purification of an his-tagged protein

[Bazeille Nicolas]

Hello everybody,


For a long time I try to purify a his tagged protein. At the beginning, I load
the cells extract in a Nickel column. The result are great, about 10 mg of
protein per liter of culture. Unfortunatly, it still rest a small amount of
contaminants.

I 've tried to load the rich-protein fraction in an heparin column but it does
not work well, no more contaminants are eliminated. So, I check for others
solution wich are :

immunoaffinity column : Affi-gel (Biorad)
Gel filtration : Sephadex G-75
gradient of ammonium sulfate precipitation according to Englard et al.

However, I'll take so much time...

So, maybe, someone possess some others easier solutions to help me in
purification.
Thanks a lot.