Hi, if you look at papers on crystallization of the E.coli protein ROP,
you might find interesting info, in particular e.g.:
Papanikolau Y, Kotsifaki D, Fadouloglou VE, Gazi AD, Glykos NM, Cesareni G,
Kokkinidis M.
Ionic strength reducers: an efficient approach to protein purification and
crystallization. Application to two Rop variants.
Acta Crystallogr D Biol Crystallogr. 2004 Jul;60(Pt 7):1334-7
(sounds like a lot of work, but you asked for it ... ;-) )
volatility is obviously a big problem, but as for cryo use paratone-N (or
related dry highly viscous, see previous discussions on its behaviour on
ccp4bb) oil, thats probably the easiest thing to do. (only thing ever work
for me with methanol and ethanol)
obvioulsy you can try butanols etc and MDP as the less volatile relatives.
HTH,
Tommi
ps
sounds suspiciously close to ROP in size...
not a fourhelix bundle is it??? (none of my business obviously though)
(on another note i think it would be nice if people would subscribe with
their institute email addresses so that we are all on the same
level in public discussions. not that it should be mandatory but it would
be sort of nice given its a "professional" forum)
Quoting shivesh kumar <[log in to unmask]>:
> Dear all
> Sorry for non-CCP4 query.
> I have crystallized a 7kDa protein in 50-60% of isopropanol,pH
> 4.0-4.6.Theinteresting thing is that the xtal appears within 5 hrs at
> 16 degree.
> The protein conc is 5mg/ml and drop size is 3+1 with mother liquor 300
> micro
> lt.Numerous xtals appears and but small is size.Do anyone can share
> their
> experience with Isopropanol as a precipitant and to improve the xtal
> quality
> with other precipitants.All suggestions are welcome.
> Thanx in advance.
> Shivesh
>
--
Tommi Kajander, Ph.D.
Macromolecular X-ray Crystallography
Research Program in Structural Biology and Biophysics
Institute of Biotechnology
P.O. Box 65 (Street address: Viikinkaari 1, 4th floor)
University of Helsinki
FIN-00014 Helsinki, Finland
Tel. +358-9-191 58903
Fax +358-9-191 59940
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