Rui-- We have crystallized several proteins that required 0.5 M NaCl in the protein buffer....getting our initial hits from commercially available screens. You might leave the salt concentration as it is for your initial crystallization screens and see what you get.
Sometimes proteins are stabilized when you add small molecular weight PEGs to the protein buffer---e.g. 1-5%. In some instances, these are a good substitute for the higher concentration of salt required in the protein buffer, ie you can lower your salt concentration by the addition of the lower mol wt PEGS. HTH! annie Annie Hassell Glaxo Smithkline 5 Moore Drive RTP, NC 27709 919/483-3228 919/483-0368 (FAX) annie.m.hass...@gsk.com "rui" <ruis...@gmail.com> Sent by: "CCP4 bulletin board" <CCP4BB@JISCMAIL.AC.UK> 29-Jun-2009 22:32 Please respond to "rui" <ruis...@gmail.com> To CCP4BB@JISCMAIL.AC.UK cc Subject [ccp4bb] can I try crystallization in high salt? Dear All, I have a peri domain protein that is stable in high salt concentration(500 mM), if I dialysis to a lower salt buffer and then concentrate, it'll preticipate out. If I need to crystallize it, can I use the high salt buffer? Is there any optimization kits that could help to increase the solubility? Thanks.
