Dear Cameron,
Sokalan CP7 is a maleic acid/acrylic acid copolymer manufactured by
BASF. You can find some (limited) information about the chemistry of
some Sokalans within the BASF web resources. We describe our tests of
that polymer as a precipitant in the following paper:
Grimm C et al. Acta Crystallogr D Biol Crystallogr. 66: 685-697.
Just send me a PM if you need a copy.
Best wishes,
Clemens
Zitat von CAMERON FYFE <[email protected]>:
Hi everyone,
I have been working with a protein 182 kDa in size and the protein
has been purified in 200 mM NaCl, 50 mM Tris, and pH7.5. After
incubating with protease and purifying by size exclusion I have
taken one of the main peaks and managed to get good looking crystals
with the largest being 1 mm long and 0.2 mm wide with variable
thickness. When the SEC purified peak is run on an SDS PAGE gel
there are multiple bands with a combined molecular weight that adds
up to the original proteins size and does not contain the protease
used (verified by MS). The successful crystallisation condition
contains 100 mM Potassium Chloride, 100 mM HEPES pH 7.5, 25% SOKALAN
CP 7. We are using a cryo condition using 30% Glycerol (anything
lower has water rings) and we found the crystallisation condition
crashes with PEG400 and Ethylene Glycol. The initial screening
condition crystal was taken to Diamond and we got diffraction to 4.9
Å. I have tested several of these crystals some of which show weak
dif
fraction however most of which do not diffract at home.
I feel the result of the protease digestion has resulted in a
complex of domains held by non-covalent interactions has anyone any
advice for optimising crystals like this?
SOKALAN CP 7 seems to be a relatively exotic precipitant with little
information available online would anyone have any experience of
using it or even some information on its structure?
Thanks,
Cameron
Cameron Fyfe
Institute of Infection, Immunity and Inflammation
Sir Graeme Davies Building
120 University Place
University of Glasgow
Glasgow G12 8TA
Tel +44 (0)141 330 6481
[email protected]
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Dr. Clemens Grimm
Institut für Biochemie
Biozentrum der Universität Würzburg
Am Hubland
D-97074 Würzburg
Germany
e-mail: [email protected]
phone : +49 0931 31 84031
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