Re: [ccp4bb] off-topic: detergents for the stabilisation of water-soluble proteins
I also recommend you to check Dan's link on the paper for stabilising protein solubility. I have similar experience. I got high yield, soluble protein but aggregates once I have purified concentrated protein. Before venturing to the detergent area, I would suggest using other additives first (kosmotropes, chaotropes, amino acid, sugars and alcohols). I managed to get it work in high NaCl, KCl and NaBr. I managed to purify the protein, put it in Tris buffer with low NaCl. I concentrated the protein and work fast enough before it crashes (my protein usually crashes overnight). Then aliquot out the protein in different eppendorf tubes containing different additives, leave it overnight; the next day, I spun all the tubes and check for aggregation (of course, make sure you leave a control, which in my case is Tris buffer, low NaCl; just for a point of comparison). I got 7 tubes then which do not have aggregated pellet; I left them for few more days; 4 of them aggregated, and 3 of them looks okay. Allan Quoting Vitali Stanevich stanev...@wisc.edu: Hi, Sorry for off-topic question. Does anyone have experience of the stabilisation of water-soluble proteins by detergents? Protein I'm working with is definitely water-soluble and has high yield, but, unfortunately, not very stable. Especially during concentration. So, we thought that adding some detergents may one of the ways to stabilise protein. So, did anyone do it before or may be know published examples? Any suggestions on the detergent type/concentration would be welcome. Thanks, Vitali -- Allan Pang Visiting Scientist G35 Joseph Priestley Building Queen Mary University of London 327 Mile End Road London, UK E1 4NS Phone number: 02078828480 Twitter: @xerophytes
Re: [ccp4bb] off-topic: detergents for the stabilisation of water-soluble proteins
Going in a different direction with my reply here. Is your pI close to your current buffer ? Move at least one unit away from the theoretical pI. Do you have a friend with a real time pcr machine ? Then get some sypro orange and check out the thermal stability of your protein under various conditions. Google for thermal melt Ericsson or Greg Crowther you'll get a paper (actually these are two different papers). Jürgen .. Jürgen Bosch Johns Hopkins Bloomberg School of Public Health Department of Biochemistry Molecular Biology Johns Hopkins Malaria Research Institute 615 North Wolfe Street, W8708 Baltimore, MD 21205 Phone: +1-410-614-4742 Lab: +1-410-614-4894 Fax: +1-410-955-3655 http://lupo.jhsph.edu On Oct 12, 2012, at 12:52, Vitali Stanevich stanev...@wisc.edu wrote: Hi, Sorry for off-topic question. Does anyone have experience of the stabilisation of water-soluble proteins by detergents? Protein I'm working with is definitely water-soluble and has high yield, but, unfortunately, not very stable. Especially during concentration. So, we thought that adding some detergents may one of the ways to stabilise protein. So, did anyone do it before or may be know published examples? Any suggestions on the detergent type/concentration would be welcome. Thanks, Vitali
Re: [ccp4bb] CCP4 update 6.3.0 006
Hi Ben, Applications launched from Finder and Spotlight get environment variables from ~/.MacOSX/environment.plist (before 10.8) their own Info.plist (10.8) and launchd (system-wide) and not .tcshrc etc. Sounds like to get the updater to work from Finder for all users you have to set your $CCP4 in launchd.conf Not sure if it's worth the effort. The environment is probably set correctly (somewhere) on the machine that was used to install CCP4... http://apple.stackexchange.com/questions/57385/where-are-system-environment-variables-set-in-mountain-lion http://www.dowdandassociates.com/content/howto-set-environment-variable-mac-os-x-etclaunchdconf Dmitry On 2012-10-12, at 3:46 PM, Ben Eisenbraun wrote: On Mon, Oct 08, 2012 at 06:20:59PM +, Ronan Keegan wrote: Dear CCP4 Users, A CCP4 update has just been released, consisting of the following changes: Hi Ronan et al, The update client on OS X doesn't seem to like our installation and dies with: Can't make class cfol of alias programs:i386-mac:ccp4:6.3.0:lib_exec:Update.app: into type Unicode text But I found an odd workaround. If I double-click the Update.app in Finder, I get the administrator password prompt, enter the credentials, and then the updater tells me that $CCP4 is unset, etc. I can then run 'open Update.app' from the shell, and it inherits $CCP4 and runs correctly. Any ideas? The workaround works, but since I don't really know why, I don't feel particularly good about it. Also, my installation is on NFS and is not owned by root, so it doesn't require administrator privileges to update. It would be nice if the application checked for write privileges before assuming it needs to be run with escalated privileges. -ben -- | Ben Eisenbraun | SBGrid Consortium | http://sbgrid.org | | Harvard Medical School | http://hms.harvard.edu |
Re: [ccp4bb] Nobel Prizes for 3D Molecular Structure
Just want to make sure anyone interested in Nobel Prizes knows about this existing page: http://proteopedia.org/wiki/index.php/Nobel_Prizes_for_3D_Molecular_Structure best regards, Joel Sussman
