I think adding 5% glyecrol has a big effect on the solubility, so conditions would have to be re-optimized if glycerol is included. In the case i am aware of also solubility was increased, but that could be compensated by higher PEG and/or lower salt concentration (in the salting-in region).
There are really two questions here: If crystallization conditions have already been optimized, will adding glycerol interfere with crystallization? probably yes. If I am starting work on crystallizing a new protein and I know it is stabilized by glycerol, should I avoid glycerol? No. eab Clayton, Gina Martyn wrote:
Hi Ray I have seen glycerol at less than 5% in the protein buffer prevent crystal growth completely and when removed from the buffer has resulted in very nice crystal growth of the glycerol free protein. Best Gina ------------------------------------------------------------------------ *From:* CCP4 bulletin board on behalf of Ray Brown *Sent:* Thu 10/03/2011 17:04 *To:* CCP4BB@JISCMAIL.AC.UK *Subject:* [ccp4bb] glycerol Hi all, I was intrigued by the recent question of whether glycerol had any adverse effects on the final purity of protein isolated by chromatography. Glycerol certainly helps to solubilize some proteins. Does anyone know of any negative effects of glycerol in protein purification, on protein crystal quality or use in cryocrystallography and on X-ray diffraction results? Cheers. Ray Brown Notice: This e-mail message, together with any attachments, contains information of Merck& Co., Inc. (One Merck Drive, Whitehouse Station, New Jersey, USA 08889), and/or its affiliates Direct contact information for affiliates is available at http://www.merck.com/contact/contacts.html) that may be confidential, proprietary copyrighted and/or legally privileged. It is intended solely for the use of the individual or entity named on this message. If you are not the intended recipient, and have received this message in error, please notify us immediately by reply e-mail and then delete it from your system.
