When you give the composition of the screen condition, you must also give
the conditions of
the protein buffer, since you get crystals when the two are mixed.
If you analyse many small salt crystals by SDS-PAGE you may still get
staining since protein
will precipitate on the salt crystals.
Enrico.
On Tue, 27 Sep 2011 18:02:18 +0200, Mark J van Raaij
<mjvanra...@cnb.csic.es> wrote:
Hi Christopher,
you'll have to try to find out how they mix the components at MD and if
they pH the solution afterwards or before (or not at all...) and to
which pH. You can ask them; or try different mixing/pHing protocols on a
small scale and see if one works in keeping all in solution.
Mark
Mark J van Raaij
Laboratorio M-4
Dpto de Estructura de Macromoleculas
Centro Nacional de Biotecnologia - CSIC
c/Darwin 3
E-28049 Madrid, Spain
tel. (+34) 91 585 4616
http://www.cnb.csic.es/content/research/macromolecular/mvraaij
On 27 Sep 2011, at 17:55, Browning Christopher wrote:
Dear All,
My question might be a bit out of place, but perhaps someone can help.
I've screened my protein in the Nuc-Pro screen from Molecular
Dimensions and found some crystals in condition B10. They seem to be
protein crystals as they are not highly optically active and look
different to salt crystals. So condition B10 consist of 10% PEG 4K,
50mM Imidazole pH 7.2, 20mM Zinc sulfate. In the screen, this condition
is perfectly clear, but when I try and make my own screen, the whole
solution turns white. Apparently, Zinc sulfate/Imidazole can be used
for staining SDS-gels, but that does not really help my a lot. Does
anybody have an idea how I might be able to keep everything in
solution, seeing that the MD guys managed somehow...... I'm a bit
desperate as I don't have many hits for this protein.
Cheers,
Chris B
--
Dr. Christopher Browning
Post-Doctor to Prof. Petr Leiman
EPFL
BSP-416
1015 Lausanne
Tel: 0041 (0) 02 16 93 04 40
--
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, CE Saclay, 91191 Gif-sur-Yvette, FRANCE
http://www-dsv.cea.fr/en/institutes/institute-of-biology-and-technology-saclay-ibitec-s/unites-de-recherche/department-of-molecular-engineering-of-proteins-simopro/molecular-toxinology-and-biotechnology-laboratory-ltmb/crystallogenesis-e.-stura
http://www.chem.gla.ac.uk/protein/mirror/stura/index2.html
e-mail: est...@cea.fr Fax: 33 (0)1 69 08 90 71
