Hi Ed,
do you have an rule of thump estimating what imidazol concentration would
be bad?
I suppose 50 mM is not high enough to be bad. I once kept a protein at 4
deg C in 50 mM Imidazole/HCl, 5 mM NaN3, 1 mM DTT, pH 7.0). The protein
was fine for about half a year. Maybe I was very lucky.
Best regards, Daniel
--
Daniel Schlieper email: [EMAIL PROTECTED]
Molecular Motors Group phone: +44 1883 722306 (x 305)
Marie Curie Research Institute fax : +44 1883 714375
The Chart, Oxted RH8 0TL, UK web : http://mc11.mcri.ac.uk
On Fri, 18 Jul 2008, Thomas Edwards wrote:
I was wondering - why is imidazole bad for proteins?
I've always heard that high concentrations are "bad" for proteins, but a
bit of googling did not reveal the answer. Does it actually react with
side chains, or cause unfolding/aggragation?
Just wondering...
Good tip with the His-SELECT media - thanks Artem!
Ed
______________
T.Edwards Ph.D.
Garstang 8.53d
Astbury Centre for Structural Molecular Biology
University of Leeds, Leeds, LS2 9JT
Telephone: 0113 343 3031
<http://www.bmb.leeds.ac.uk/staff/tae/>
http://www.bmb.leeds.ac.uk/staff/tae/
<http://www.bmb.leeds.ac.uk/staff/tae/Research>
"The doubter is a true man of science; he doubts only himself and his
interpretations, but he believes in science". ~Claude Bernard
________________________________
From: CCP4 bulletin board [mailto:[EMAIL PROTECTED] On Behalf Of
Jacob Keller
Sent: 18 July 2008 01:04
To: CCP4BB@JISCMAIL.AC.UK
Subject: [ccp4bb] Imidazole's ability to chelate metal ions
Dear Crystallographers,
Does anybody happen to know whether imidazole is able to chelate metal
ions in solution? It seems reasonable that since it can compete for
binding to IMAC resins, it should have some affinity for at least Ni++
and Co++, but what about metal ions like Ca++ and Mg++? I assume that
the affinity is weak, but at the concentrations at which we are wont to
use it in our elutions (~100-500 mM), does it not seem likely that other
metal ions are being competed away from our proteins as well?
Jacob Keller
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Jacob Pearson Keller
Northwestern University
Medical Scientist Training Program
Dallos Laboratory
F. Searle 1-240
2240 Campus Drive
Evanston IL 60208
lab: 847.491.2438
cel: 773.608.9185
email: [EMAIL PROTECTED]
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