Hi, I have a membrane protein with a C-terminal S-tag, and there is no cleavage site for the S-tag (novagen, e.g, thrombin, EK). I wonder whether I still can use this for purification without cleavage of the S-tag. Here are my questions:
1) How to release the protein bound to S-tag resin? I noticed they suggest 3M NaSCN, 3M MgCl2 or 0.5 M Citrate pH2, but these sound crazy for a membrane protein. Does anyone have experience with this? 2) It seems that S-tag resin has lower binding capacity than does Ni resin. Did anyone ever use S-tag resin for purification of at least 10 mg protein? I would probably put a his tag on my protein for purification later. Many thanks for any suggestions. Yong
