1. Yes, Ion Exchange (not just Anion as we don't know anything about their protein (unless I missed an email)) is a great capture step if you have the time to mess about.
2. When I have been refolding recently, after the refolding step we have found that a good, old-fashioned Ammonium sulphate cut step (well, two of them) has worked really, really well. It takes a bit of tinkering, but it really does work a treat. Email me if you want to know about inner design of such an experiment. We are working with an untagged version of the protein as we use yet another affinity step that doesn't require it....... see below. 3. If you know something about your protein, you might be able to use a different affinity step to cature it also. Heparin - Your protein may interact with a heparin column, even if you have no reason to think it will. Blue HP - Actually, the only reason I mention this one is that it has worked so well for one of the proteins I am working on at the mo. GE reckon if your protein has an affinity for nucleotides, nicotinamides blah blah blah it might interact with your protein. This can be a really powerful capture column if it does. 4. A great tag to capture it would be a Z-tag. cheers charlie > An anion exchange column with a large enough bed volume might be used to > concentrate the protein. You probably need to change the pH of the > solution so that the protein sticks to the column. > > On Thu, 2009-09-03 at 17:05 +0800, Xuan Yang wrote: >> Dear Dr Ku, >> >> It was a wonderful idea! However, the refolding buffer contained 500mM >> L-Arg and 1mM EDTA. >> >> And I want to try other affinity columns, just don't know what resin >> would be appropriate. >> >> Sincerely, >> >> Xuan Yang >> >> >> 2009/9/3 Shao-Yang Ku <s...@embl-hamburg.de> >> Can you put a 6His-tag on your protein and add some Ni-NTA >> beads to your solution to capture (and concentrate) the >> properly folded molecules? >> >> >> >> Quoting "Xuan Yang" <pattisy...@gmail.com>: >> >> Dear All, >> >> I am working on protein refolding via dialysis in >> large volumn >> (typically 2~4 litters). It was problematic when I >> wanted to concentrate the >> solution to at least less than 500ml. If you know any >> device appropriate for >> such task, please help me out:) >> >> Thanks in advance! >> >> Sincerely, >> >> Xuan Yang >> >> >> >> >
