Dear Fred, Was BME in one of the buffers used for expression or purification? Was any other cysteine reagent used? With 1.3 Å, I would fit a BME modification and see if it fits well. You could also setup crystallizations in the presence of DTT to see if you can get rid of the modification.
Best, Herman Von: CCP4 bulletin board [mailto:[email protected]] Im Auftrag von Bio Physics Gesendet: Mittwoch, 13. Mai 2015 00:16 An: [email protected] Betreff: Re: [ccp4bb] CYS mod No, it is not sulfenic acid or so, I had that in differend structure. It is L shaped from S, and linear if I put SCX mutaion (another 1.4A way a nice blob). My resolution is 1.3 A. On Tue, May 12, 2015 at 4:18 PM, Artem Evdokimov <[email protected]<mailto:[email protected]>> wrote: Looks like a wrong shape for tetrahedral acid ... On May 12, 2015 4:07 PM, "Boaz Shaanan" <[email protected]<mailto:[email protected]>> wrote: Hi, As I've just written to David, maybe it's sulfenic acid (result of radiation damage?). I've had those in some cases. See attached scheme for the chemistry and other possibilities for Cys modification by oxidation. Boaz Boaz Shaanan, Ph.D. Dept. of Life Sciences Ben-Gurion University of the Negev Beer-Sheva 84105 Israel E-mail: [email protected]<mailto:[email protected]> Phone: 972-8-647-2220 Skype: boaz.shaanan Fax: 972-8-647-2992 or 972-8-646-1710 ________________________________ From: CCP4 bulletin board [[email protected]<mailto:[email protected]>] on behalf of Bio Physics [[email protected]<mailto:[email protected]>] Sent: Tuesday, May 12, 2015 11:57 PM To: [email protected]<mailto:[email protected]> Subject: Re: [ccp4bb] CYS mod Hi All, I have same type of modified CYS !!! No BME. On Tue, May 12, 2015 at 2:59 PM, David Schuller <[email protected]<mailto:[email protected]>> wrote: So far almost everyone is suggesting BME. I didn't do the purification & crystallization myself, but I am told: Buffer was HEPES cryo was ethylene glycol, glycerol and DMSO. Some MgSO4 and KPO4 No BME, but maybe some DTT. Purified from a proteobacterium. On 05/12/15 15:20, Dyda wrote: What is in buffer? Perhaps DTT and cacodylate? Fred [32m******************************************************************************* Fred Dyda, Ph.D. Phone:301-402-4496<tel:301-402-4496> Laboratory of Molecular Biology Fax: 301-496-0201<tel:301-496-0201> DHHS/NIH/NIDDK e-mail:[email protected]<mailto:e-mail%[email protected]> Bldg. 5. Room 303 Bethesda, MD 20892-0560 URGENT message e-mail: [email protected]<mailto:[email protected]> Google maps coords: 39.000597, -77.102102 http://www2.niddk.nih.gov/NIDDKLabs/IntramuralFaculty/DydaFred ******************************************************************************* [m -- ======================================================================= All Things Serve the Beam ======================================================================= David J. Schuller modern man in a post-modern world MacCHESS, Cornell University [email protected]<mailto:[email protected]>
