Dear Andre,
66% solvent is on the high side but not a good reason for poor resolution.
Other with similaa solvent content have achieved resolutions of 1.5 Ang.
and even better.
I would screen at a lower protein concentration. It will require more
precipitant
and you should end up with less water in the cell.
Enrico.
On Tue, 29 Oct 2013 16:18:21 +0100, Andre Godoy <andre_go...@yahoo.com.br>
wrote:
Dear all
I'm trying to solve a beautiful large crystal that, unfortunately,
doesn't go further than 5 A resolution. I believe that in this case, the
lack of resolution is due the high solvent content (about 66%).
Therefore, my next strategy should be the dehydratation. Yet, I never
(sucessfully) did that. I read different approachs, were people
equilibrate crystals in dehydratation solution for days, or do more than
20 steps, or add solvents. Since i never had sucess in my trials, I was
thinking that someone can suggest a protocol (should I remove all salt?,
should I keep the additive concentration?, how much precipitant should I
add? how many steps?).
crystal condition: 23% PEG 3350, 0.2M NaCl, 0.1M Tris pH 8.5, 3%
galactose (orthorhombic crystals, with about 0.6 x 0.6 mm)
all the best,
Andre Godoy
--
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
http://www-dsv.cea.fr/ibitecs/simopro/ltmb/cristallogenese
LTMB, SIMOPRO, IBiTec-S, CE Saclay, 91191 Gif-sur-Yvette, FRANCE
http://scholar.google.com/citations?hl=en&user=Kvm06WIoPAsC&pagesize=100&sortby=pubdate
http://www.chem.gla.ac.uk/protein/mirror/stura/index2.html
e-mail: est...@cea.fr Fax: 33 (0)1 69 08 90 71
