Not strange at all:
Reading from:
http://www.chem.gla.ac.uk/research/groups/protein/mirror/stura/cryst/add.html
"Zinc acetate or sulfate 0.2-5mM It inevitably reduces protein solubility.
It can act as an inhibitor. Essential for activity of various enzymes"
Zinc reduces protein solubility and often aggregates proteins. In a case
of a zinc binding protein you may need to add 100-200 mM imidazole to
control even 0.2mM concentrations of this ion.
Without good control, you will end up by depleating the zinc within the
precipitate
and end up without zinc in your binding site.
This is what you got.
Enrico.
On Wed, 31 Mar 2010 18:11:46 +0200, zq deng <dengzq1...@gmail.com> wrote:
hello everyone, recently i purify a protein conteining zinc binding
domain,and i want to determine its structure.i get the crystal,but poor
diffraction.so i try to adding zinc into the protein to optimize the
crystal,but the protein precipitate immidiately even the znic is 1
mM.BTW,we use the protein to do zinc scan,we don't find the zinc. does
anyone have some advice?hello everyone, recently i purify a protein
conteining zinc binding domain,and i want to determine its structure.i
get
the crystal,but poor diffraction.so i try to adding zinc into the
protein to
optimize the crystal,but the protein precipitate immidiately even the
znic
is 1 mM.BTW,we use the protein to do zinc scan,we don't find the zinc.
does
anyone have some advice?
--
Enrico A. Stura D.Phil. (Oxon) , Tel: 33 (0)1 69 08 4302 Office
Room 19, Bat.152, Tel: 33 (0)1 69 08 9449 Lab
LTMB, SIMOPRO, IBiTec-S, CEA Saclay, 91191 Gif-sur-Yvette
Cedex FRANCE http://www-dsv.cea.fr/en/ibitecs/82
http://www.chem.gla.ac.uk/protein/mirror/stura/index2.html
e-mail: est...@cea.fr Fax: 33 (0)1 69 08 90 71
