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Re: [ccp4bb]: high solvent content?

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Rui Zhao wrote:

>  I wonder if somebody can give me some
> suggestions/comments that if the poor diffraction can be caused by the
> high
> solvent content or the intrinsic flexbility is likely to be the real
> cause?  If the high
> solvent content does contribute to the poor diffraction, did anybody
> have
> experience/tricks to overcome this problem?
>     Thank you very much for your help.                Rui.

Well, maybe this help you:

1 - try to collect data from very fresh crystals (growing time sometimes
help us to distinguish between slightly different  molecule conformations,
leading to better diffracting crystals);

2 - maybe you have problems while flash-cooling your crystals (remember,
not only ice is an important aspect in this issue...). Be sure that your
protocol is a good one (see details in Garman, E. F. & Schneider, T. R.
(1997),  J Appl Cryst, 30: 211-237). You can check this doing a room
temperature data collection. As another approach, you can try crystal
annealing (Harp, J. M., et al. (1998), Acta Cryst. D54: 622-628) .

Good luck,


Ricardo Aparicio
PhD Student at the Brazilian Synchrotron LNLS - http://www.lnls.br
Protein Crystallography Group
Phone +55(19)2874520 / Fax +55(19)2874632