Is there any reason why crystallographers have not routinely substituted NaBr for NaCl in protein crystallization stocks, or even pH'd their TRIS with HBr, if there is no NaCl? Wouldn't it make a lot of sense, since there would always be a possibility for a Br- derivative, and the price difference is pretty small? Also, a data set at the Br- peak would always be able to distinguish "heavy H2O" from weak halide sites once the structure was solved, even if the sites were not good enough for phase determination themselves.
JPK On Wed, Jun 15, 2011 at 7:35 AM, Stephen Graham <sc...@cam.ac.uk> wrote: > You might also want to try: > > http://www.ncbi.nlm.nih.gov/pubmed?term=12499536 > > Cheers, > > Stephen > > On 15 June 2011 02:09, Robbie Joosten <robbie_joos...@hotmail.com> wrote: >> Hi Wolfram, >> >> This was an early study on the subject: >> http://www.ncbi.nlm.nih.gov/pubmed/8594192 >> The software is still accessible via the STAN server. >> >> Cheers, >> Robbie >> >>> Date: Tue, 14 Jun 2011 17:51:21 -0400 >>> From: wtem...@gmail.com >>> Subject: [ccp4bb] non-waters among structured solvent atoms >>> To: CCP4BB@JISCMAIL.AC.UK >>> >>> Dear colleagues, >>> following a discussion in our lab, I have volunteered to dig out >>> articles from the literature about erroneous assignments of non-water >>> entities such as metal ions, halides in protein models. For example I >>> have the faint recollection that data mining of the PDB for suspect >>> "water" assemblies matching the geometry of coordinated cations has >>> previously been described. But none of my google searches has turned >>> up the references I was looking for. Could someone point me in the >>> right direction, please? >>> Many thanks, >>> Wolfram Tempel >> > > > > -- > Dr Stephen Graham > 1851 Research Fellow > Cambridge Institute for Medical Research > Wellcome Trust/MRC Building > Addenbrooke's Hospital, Hills Road > Cambridge, CB2 0XY, UK > Phone: +44 1223 762 638 > -- ******************************************* Jacob Pearson Keller Northwestern University Medical Scientist Training Program cel: 773.608.9185 email: j-kell...@northwestern.edu *******************************************
