Hi Nicola, We have had success simply soaking zinc into the crystal prior to data collection. This has worked very well for a number of proteins. We simply add some zinc to the cryo-protectant and leave it to soak for various times.
Hope this helps. Kind regards Sheena Sheena McGowan Head, Structural Microbiology Laboratory Monash Biomedicine Discovery Institute and Department of Microbiology Adjunct Senior Research Fellow | Monash Institute of Pharmaceutical Sciences Monash University Rm 137, Building 76, Wellington Rd, Clayton Victoria, AUSTRALIA 3800 T + 61 3 9902 9309 | M +61419399454 E sheena.mcgo...@monash.edu <mailto:sheena.mcgo...@monash.edu> | Skype s.mcgowan Dept webpage <http://med.monash.edu.au/microbiology/research/mcgowan.html> | Bio/Publications/Projects <http://monash.edu/research/explore/en/persons/sheena-mcgowan(f37de249-cb47-4592-a393-4161e272628b).html> | Lab Facebook Page <https://www.facebook.com/McGowan-Lab-1423981767901922/> | ORCID <http://orcid.org/0000-0001-6863-1106> | Google Scholar <https://scholar.google.com.au/citations?user=nfGnhCkAAAAJ&hl=en> | Lorne Conference for Protein Structure and Function <http://lorneproteins.org/> 10th - 14th February, 2019 I acknowledge the Traditional Owners and Custodians of the lands on which I live and work and pay my respects to Elders past, present and future. > On 10 Dec 2018, at 8:31 am, Nicola Evans > <0000251ca3b4615e-dmarc-requ...@jiscmail.ac.uk> wrote: > > From a fluorescence scan it would appear a protein I am working on has zinc > in it. The occupancy is likely to be very low however (a structural homologue > has several zincs in the x-ray crystal data but at 0.5 occupancy), as there > isn't anything obvious in the electron density map (perhaps some of the > waters are zinc) and an anomalous difference map wasn't possible to obtain on > our last beamtime. > > Ideally I would want to re-express the protein with zinc added to the culture > conditions, but I am time-restained, so I was wondering if it is possible to > add zinc to purified protein instead? I have heard it can cause proteins to > crash out. I have quite a lot of protein frozen so I can try a few things. I > would appreciate any advice on how much to add from anyone who has had > success with this before? > > Thanks in advance! > > ######################################################################## > > To unsubscribe from the CCP4BB list, click the following link: > https://www.jiscmail.ac.uk/cgi-bin/webadmin?SUBED1=CCP4BB&A=1 ######################################################################## To unsubscribe from the CCP4BB list, click the following link: https://www.jiscmail.ac.uk/cgi-bin/webadmin?SUBED1=CCP4BB&A=1
