While there is no systematic study (I think) on this we have observed RH
control systems and concentration of solutes can have the same effect -
Photosystem 1 crystals were dehydrated by transferring them from 20% to
40% PEG6000 resulting in a smaller unit cell and better diffraction
Hi Andre,
a very effective method is the use of a humidity control device. It has
the great advantage that you can characterize changes that occur and
also move straight to data collection. There are several HC1 devices in
Europe (developed here at the EMBL and available at Diamond, BESSY and
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
/2012/01/31/jbc.M111.327536
Best Regards
Harkewal
From: CCP4 bulletin board [CCP4BB@JISCMAIL.AC.UK] on behalf of Andre Godoy
[andre_go...@yahoo.com.br]
Sent: Tuesday, October 29, 2013 10:18 AM
To: CCP4BB@JISCMAIL.AC.UK
Subject: [ccp4bb] crystals with large solvent
I wonder if there is a big difference between dehydrating in a drop, where the amount of
mother liquor is essentially unlimited, and dehydrating a mounted crystal in something
like the FMS, where there is only a thin film of ML on the surface. In the latter case,
once the surface fluid is gone,
Dear Andre,
you could try with the protocol described in the following paper
Acta Crystallogr D Biol Crystallogr. 2013 69,920-3.
Using high-throughput in situ plate screening to evaluate the effect of
dehydration on protein crystals.
Douangamath A, Aller P, Lukacik P, Sanchez-Weatherby J,
Hi, you could try dehydration in microdialysis buttons - this allows for slow
gradual increase in PEG over few days and full control of other parameters,
including lowering salt concentration.
It was the only dehydration method that worked well for our large membrane
protein:
Hi Andre,
Are you sure that the cryoprotectant has been optimized?..I am sure you
must have already done it but just in case..sometimes the cryo protectant
which makes the ice rings disappear is not the best one and playing around
that concentration as well as different alternatives can have a
