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
