Dear Nicola,
Happy New Year
It may or may not be possible to re-constitute Zn into purified protein.
Some binding sites are very hard to fill back up once Zn is gone (for
example sites with more than one -SH ligand can and often do undergo
oxidative crosslinking in the absence of a stabilizing
Hi Nicola,
I would just add zinc solution to the protein before the crystallization
and/or to the drop with crystals.
An important thing to keep in mind is that Zn salt solutions will have
low pH, unless a sufficient buffer is used.
I recommend having a look at the article
"Characterizing
they might be small.
What wavelength was used for the data collection?
HTH
Raghu
-Original Message-
From: CCP4 bulletin board On Behalf Of Nicola Evans
Sent: Monday, December 10, 2018 03:02
To: CCP4BB@JISCMAIL.AC.UK
Subject: [ccp4bb] Adding Zinc to Protein
From a fluorescence scan
Hi Nicola,
One way to do it is to dilute your protein, 10-100 times, and add zinc (also
diluted), then concentrate.
Here is the procedure we used some time ago for a zinc-binding protein:
“S100A12 was diluted to 0.1 mg/ml-1 (approximately 10 mM) in a buffer
containing 20 mM Tris-HCl pH 7.5,
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
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
