Hi Andrew, We had considerable success with MicroPIXE collaborating with the Garman group in Oxford and the Surrey Ion Beam Center. There is a tiny amount of sample needed, it's an atomic technique so the sample can be from that old tube that hadn't been discarded yet, and it provides identification and with a little care, stoichiometry. At the risk of blowing our own horn we have a paper on this in the Journal of the American Chemical Society that is public access, Grime et al., High-Throughput PIXE as an essential quantitative assay for accurate metalloprotein structural analysis: Development and application, 142,1, 185-197. It is publicly available at https://pubs.acs.org/doi/abs/10.1021/jacs.9b09186 and contains citations to the major papers in the field. We were able to use it to identify a previously unidentified metal modeled as a water cluster and from that produce a model of the actual ligand that was present.
Best, Eddie https://getacrystal.org - The High-throughput Crystallization Screening Center Edward Snell Ph.D. President and CEO | Hauptman-Woodward Medical Research Institute Director | NSF BioXFEL Science and Technology Center BioInnovations Chaired Professorship | University at Buffalo, SUNY p: +1 716 898 8631 | f: +1 716 898 8660 e: esn...@hwi.buffalo.edu<mailto:esn...@hwi.buffalo.edu> skype: eddie.snell Hauptman-Woodward Medical Research Institute 700 Ellicott Street | Buffalo, NY 14203-1102 hwi.buffalo.edu<https://hwi.buffalo.edu/> [hwi-logo-primary-horizontal] From: CCP4 bulletin board <CCP4BB@JISCMAIL.AC.UK> On Behalf Of Andrew Lovering Sent: Thursday, January 7, 2021 9:13 AM To: CCP4BB@JISCMAIL.AC.UK Subject: [ccp4bb] Elemental Analysis Dear CCP4ers We have a protein with moderate resolution (mid 2s) with obvious metal ion density holding the oligomer together. We can make an educated guess that the ions are likely to be Mg/Ca This sender is trusted. sophospsmartbannerend Dear CCP4ers We have a protein with moderate resolution (mid 2s) with obvious metal ion density holding the oligomer together. We can make an educated guess that the ions are likely to be Mg/Ca and can look at co-ordination and bond lengths.....but I have a more specific question - would it be appropriate to try and identify these at the beamline? Obviously the edges for these aren't accessible to sit either side of the peak but perhaps something like micro-pixe would be fun; is this done routinely? https://doi.org/10.1016/j.pbiomolbio.2004.09.005 Best & thanks in advance Andy ________________________________ To unsubscribe from the CCP4BB list, click the following link: https://www.jiscmail.ac.uk/cgi-bin/WA-JISC.exe?SUBED1=CCP4BB&A=1 ######################################################################## To unsubscribe from the CCP4BB list, click the following link: https://www.jiscmail.ac.uk/cgi-bin/WA-JISC.exe?SUBED1=CCP4BB&A=1 This message was issued to members of www.jiscmail.ac.uk/CCP4BB, a mailing list hosted by www.jiscmail.ac.uk, terms & conditions are available at https://www.jiscmail.ac.uk/policyandsecurity/
