[ccp4bb]: is glycerol more bad than good?

["Bernhard Rupp" <br@llnl.gov>]

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Dear All :

I have a not crystallographic computing related but still interesting
question. As often in protein crystallization, firm and validated
information
is rare and thus in this case I am happy to solicit also opinion and
anecdotal evidence:

Glycerol is used to protect proteins while being stored frozen. This
is a particular issue for any high throughput operations, where the
protein cannot be processed immediately and needs to be stored in
aliquots until machine time becomes available.

Now, the question is, how high a price will you have to pay later in
crystallization success rate if you do not dialyze the glycerol out? I.e,
what
is the overall statistical chance that it is harmful vs. not?
In particular, has reduced diffraction quality (vs.non-gycerol) been
observed?
I clearly understand that some proteins do crystallize fine with
glycerol as additive, and we have it also in CRYSTOOL, but as a
principal component in the protein stock,
at lets say 10%, what's the effect? Does anybody have hard numbers
(or some statistics) on that or at least more than single case evidence for
the one or the other?

Electronic web research in Medline and inspec did not provide a lead.
Manual search in J. Crystal Growth (1889-90) where we hoped to find an
article presented at the first ICCBM conference in 88 was negative.

Please let us know if you can help with any information, references or
leads.

I'll post the summary.

Thx, BR
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Dr. Bernhard Rupp
Macromolecular Crystallography and Structural Genomics
LLNL-BBRP L448                               Phone (925) 423-3273
University of California                     Phax  (925) 424-3130
Livermore, CA 94551                          email    br@llnl.gov
URL                                 http://www-structure.llnl.gov
TB Structural Genomics Consortium  http://www.doe-mbi.ucla.edu/TB
EU Mirror  http://www.dl.ac.uk/CCP/CCP14/ccp/web-mirrors/llnlrupp
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