hi Andy Here's my tip: If the protein is not denatured, but just precipitated, you can use the precipitate as research tool, trying to see if the protein will dissolve again with additives such as EDTA or divalent metal ions, or a bit of salt, or cofactor ATP or NAD, detergent etc (anything non-denaturing)
This will learn you about what the protein likes, and helps you to make a better prep that doesn't precipitate. We saw some miracles. If its rare protein and if it dissolves again you can even try to go ahead as if nothing happened, best Joost Dr. Joost Uitdehaag Dept. Molecular Pharmacology group leader protein crystallography Schering-Plough Research Institute, Oss tel: +31-412-666738 fax: +31-412-662519 -----Original Message----- From: CCP4 bulletin board [mailto:[EMAIL PROTECTED] On Behalf Of Juergen Bosch Sent: Thursday, 02 October, 2008 4:11 To: CCP4BB@JISCMAIL.AC.UK Subject: Re: [ccp4bb] resuspending precipitated protein 6M Guanidiniumhydrochloride works pretty good, the question is only will you be able to refold it correctly ? I believe a better approach is to avoid precipitation in the first place and optimize your purification procedure in such a way that it works. When do you observe precipitate ? Dialysis, then us e a fast desalting column instead. Jürgen On 1 Oct 2008, at 06:12, ANDY DODDS wrote: > Hello, > > following on from a previous topic about precipitating protein, but I > believe a distinct caveat of this warranting a separate thread, I > would like to know people's experiences in trying to get precipitated > protein back into solution? Is there a way or are there many ways? > > Any experiences would be welcome, > > yours, > > Andy - Jürgen Bosch University of Washington Dept. of Biochemistry, K-426 1705 NE Pacific Street Seattle, WA 98195 Box 357742 Phone: +1-206-616-4510 FAX: +1-206-685-7002 Web: http://faculty.washington.edu/jbosch This message and any attachments are solely for the intended recipient. If you are not the intended recipient, disclosure, copying, use or distribution of the information included in this message is prohibited --- Please immediately and permanently delete.