Most obvious (maybe you did it already but that is not clear from your
email), why not try seeding?
- J. -
Savvas Savvides wrote:
>
> Dear colleagues,
>
> we have been growing crystals of a protein complex in sitting-drop
> geometry that stick to the bottom of the drop remarkably well. It’s as
> if they are glued onto the plastic. This makes crystal handling next
> to impossible without destroying the crystals. We have tried whiskers,
> loops, all kinds of micro-tools, and pipetting techniques to no avail.
> I can say at the outset that we have been unsuccessful in growing
> these crystals in hanging-drops or at 4 degrees. Deglycosylating the
> complex also leads to nowhere. In fact, we are only able to get
> crystals from homogeneously glycosylated protein produced in
> HEK293S/I- cells.
>
> In the meantime we are playing with the idea of siliconizing the
> sitting-drop depressions to alter the crystal/plate interface. But
> then again, nucleation events on the plastic may be the reason we are
> getting crystals in the first place. We have also thought of trying
> microseeding to have more control on nucleation issues. Our protein
> production is quite limiting and forces us to be very selective with
> our experimentation.
>
> Nonetheless, while we are waiting for fresh material to explore some
> of these ideas we would like to make the most out of the crystals we
> have grown thus far. We would therefore very much appreciate any
> input/ideas on manipulating these crystals for data collection.
>
> Best wishes
>
> Savvas
>
> ----
> Savvas Savvides
> L-ProBE, Unit for Structural Biology
> Ghent University
> K.L. Ledeganckstraat 35
> 9000 Ghent, BELGIUM
> office: +32-(0)9-264.51.24 ; mobile: +32-(0)472-92.85.19
> Email: [log in to unmask]
> http://www.lprobe.ugent.be/xray.html
>
> *From:* CCP4 bulletin board [mailto:[log in to unmask]] *On Behalf
> Of *Katarina Moravcevic
> *Sent:* Tuesday, January 27, 2009 10:52 PM
> *To:* [log in to unmask]
> *Subject:* [ccp4bb] pseudo translation
>
> Hi all,
>
> here is a question from a beginner. I have a home source data set that
> indexed and scaled in a P2 space group (a=46.704,b=59.362, c=48.783,
> alpha=90.0, beta=104.469, gamma=90.0) with predicted 2mol/au. After
> failing to get a MR solution with Phaser I ran the phenix.xtriage
> which showed that I have a large (89.18) Patterson peak at 0.5 0 0.5
> which indicates pseudo translational symmetry. I was wondering if
> there is anything I could do with this data to get around this
> problem. Given that I don't have a lot of experience any
> suggestion/explanation would be fantastic.
>
> Thanks in advance
>
> K
>
>
>
> *
>
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--
Dr. Jeroen R. Mesters
Gruppenleiter Strukturelle Neurobiologie und Kristallogenese
Institut für Biochemie, Universität zu Lübeck
Zentrum für Medizinische Struktur- und Zellbiologie
Ratzeburger Allee 160, D-23538 Lübeck
Tel: +49-451-5004065, Fax: +49-451-5004068
Http://www.biochem.uni-luebeck.de
Http://www.iobcr.org
Http://www.selfish-brain.org
Http://www.opticryst.org
--
If you can look into the seeds of time and say
which grain will grow and which will not - speak then to me (Macbeth)
--
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