Re: [ccp4bb] can I try crystallization in high salt?
In short, yes you can. Although it is often avoided due to the limitations that high salt samples may have, you still have a good chance to crystallize the protein in the original high salt buffer. In my case a small alcohol was the best precipitating agent. As with most proteins, try it, try it, try it. First find the correct buffer condition where your protein is stable and monomodal (DLS is a good tool to check this), and then start screening. Good luck, Djordje 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.
Re: [ccp4bb] can I try crystallization in high salt?
Rui-- We have crystallized several proteins that required 0.5 M NaCl in the protein buffergetting 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.
[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.
Re: [ccp4bb] can I try crystallization in high salt?
You can try including some salt to the reservoir after mixing protein and well solution. Joe rui wrote: 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.
Re: [ccp4bb] can I try crystallization in high salt?
You may also apply salting-in: if the reservoir concentration is lower than that of the protein buffer, water may evaporate from the reservoir into the drop, lowering the protein's solubility and thus maybe grow crystals. Tim -- Tim Gruene Institut fuer anorganische Chemie Tammannstr. 4 D-37077 Goettingen GPG Key ID = A46BEE1A On Mon, 29 Jun 2009, rui wrote: 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.
