Hi Darren, I'm not aware of any (membrane) protein crystal structures solved with tween20. It's heterogeneous, and its color suggests it contains impurities and/or oxidation products, making it even more heterogenous. It would be better to test the behavior of your complex in the presence of well-defined and often-used detergents such as octylglucoside, (D)DM, LDAO, C8E4 and the like. If this doesn't work only then I'd set up trials with the tween20.
Hope this helps, Bert Bert van den Berg University of Massachusetts Medical School Program in Molecular Medicine Biotech II, 373 Plantation Street, Suite 115 Worcester MA 01605 Phone: 508 856 1201 (office); 508 856 1211 (lab) e-mail: bert.vandenb...@umassmed.edu http://www.umassmed.edu/pmm/faculty/vandenberg.cfm -----Original Message----- From: CCP4 bulletin board on behalf of Darren Hart Sent: Tue 3/24/2009 11:22 AM To: CCP4BB@JISCMAIL.AC.UK Subject: [ccp4bb] OT: Crystallisation compatible detergents Hello, We can make a nice 1:1 complex between two proteins that then gradually precipitates during storage at 4 degC. With 0.005% Tween-20 the complex is stable and does not preciptate noticeably. We have used this in buffers to measure the kinetics of binding by Biacore so it is clearly compatible with "functionality". Is Tween-20 at this concentration compatible with crystallisation? Is it worth giving a go, or a waste of time? Should we try and remove it, or reprepare the complex in an alternative detergent? If we need to try an alternative, what would people recommend? Thanks in advance for your suggestions, Darren -- ********************************************************************** Dr. Darren Hart, Team Leader High Throughput Protein Lab Grenoble Outstation European Molecular Biology Laboratory (EMBL) ********************************************************************** EMBL webpages: http://tinyurl.com/6xdltl http://tinyurl.com/667jrp Email: h...@embl.fr Tel: +33 4 76 20 77 68 Fax: +33 4 76 20 71 99 Skype: hartdarren Postal address: EMBL, 6 rue Jules Horowitz, BP181, 38042 Grenoble, Cedex 9, France **********************************************************************
