RE: [ccp4bb]: aggregation

[Artem Evdokimov]

Hi,   You can try quite a few things, including:   change salinity and pH of your buffers add detergents or NDSBs add glycerol, ethylene or propylene glycol move the tag to the other terminus try a different tag, or a fusion protein approach (His-MBP, GST, SUMO, NusA, etc.) try refolding change _expression_ system     The quest for soluble, non-aggregated protein can be nearly endless J   Good luck,   Artem From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Jenny Sent: Friday, September 22, 2006 3:51 PM To: ccp4bb@dl.ac.uk Subject: [ccp4bb]: aggregation   Hi All, I'm trying to purify a protein which is expressed in soluble form.It's a His-tag protein, so when I run His-column, it's really easy to clog.In the next step size exclusion purification, the protein come off at the void volume, which suggests that the protein is severely aggregated.Does any one have any suggestions that I can modify the  purification condition so as to avoid aggregation problem?Or can I add GuHCl during His column purification so that it won't clog so easily?Thanks a lot. Jenny