Dear Nicolas ATP crystals is a reasonable answer. Thank you very much.
Best regard Chang 2012/10/12 Nicolas Foos <nicolas.f...@afmb.univ-mrs.fr>: > Dear Chang, > > i have seen ATP diffraction, it's not very different of your image. Maybe > you have only ATP in your crystals? > > Best regard > > Nicolas > > Le 12/10/12 14:56, Chang Qing a écrit : > >> Dear Tim >> >> I think your explanation is logical. But I tried ADP as ligand first >> and got crystals and diffraction. ATP in additive kit was found to >> improve the quality of crystals from cluster to single crystal. CsCl >> can go on improving the quality and finally I got crystals like this. >> Is it possible that I get some strange crystals such as CsMgCl3 or >> something else? >> Best regard >> Chang >> >> ---------- Forwarded message ---------- >> From: Tim Gruene <t...@shelx.uni-ac.gwdg.de> >> Date: 2012/10/12 >> Subject: Re: [ccp4bb] RE : [ccp4bb] Strange diffraction image >> To: Chang Qing <robie0...@gmail.com> >> 抄送： CCP4BB@jiscmail.ac.uk >> >> >> -----BEGIN PGP SIGNED MESSAGE----- >> Hash: SHA1 >> >> Dear Chang, >> >> What makes you think spots from salt crystals should not be as large? >> You have got an ordinary small molecule crystal (or probably a >> cluster of them) in the beam, with a unit cell somewhat bigger than >> that of ice judging by the extra real ice rings you've got. >> Hydrolysis of ATP and Mg2+ present - it's probably (Mg)3(PO4)2- it is >> very unsoluble http://en.wikipedia.org/wiki/Solubility_table. >> >> Best, >> Tim >> >> On 10/12/2012 09:29 AM, Chang Qing wrote: >>> >>> Hi, Thanks for answering my question. I think I'd better provide >>> more informations. These four images were taken from one crystals. >>> The distance of image1-2 is 250mm, and image3-4 is 100mm. I checked >>> more than 10 crystals and results were similar. The spots look very >>> large. The lowest resolution is about 6A. As my protein can >>> hydrolyze ATP, so protein buffer with 5mM of ATP. There is 0.2M of >>> MgCl2 in precipitant buffer with PH7.0. 0.06M of CsCl can improve >>> quality of crystals. I also setup control, in which target protein >>> was not added, and could get nothing in it. I don't think it is a >>> protein crystal. But salt spot should not be so large. And the >>> rings are not just ice-ring. As I got crystal first in hampton >>> crystal screen kit with MgCl2, TrisHCl and PEG4,000, there are only >>> rings in images from 5-6A to about 3A. >>> >>> 2012/10/12 THOMPSON Andrew >>> <andrew.thomp...@synchrotron-soleil.fr>: >>>> >>>> Hi Chang No mention of the resolution limit / oscillation range >>>> (I think I can see an ice ring, so I would guess 2.5 A?), but it >>>> looks like salt to me, with some weaker satellite peaks that may >>>> be something weird like an incommensurate phase. Did you try to >>>> index? Cheers Andy ________________________________________ De : >>>> CCP4 bulletin board [CCP4BB@JISCMAIL.AC.UK] de la part de Chang >>>> Qing [robie0...@gmail.com] Date d'envoi : vendredi 12 octobre >>>> 2012 08:11 À : CCP4BB@JISCMAIL.AC.UK Objet : [ccp4bb] Strange >>>> diffraction image >>>> >>>> Hi, everyone: >>>> >>>> I just got some strange diffraction images from crystals with >>>> triangular pyramid shape. I think this should not be protein >>>> diffraction. I never saw so strange images like this. Does anyone >>>> know what it is? Is it a kind of salt diffraction? Thank you very >>>> much >>>> >>>> Chang >> >> - -- >> - -- >> Dr Tim Gruene >> Institut fuer anorganische Chemie >> Tammannstr. 4 >> D-37077 Goettingen >> >> GPG Key ID = A46BEE1A >> >> -----BEGIN PGP SIGNATURE----- >> Version: GnuPG v1.4.12 (GNU/Linux) >> Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/ >> >> iD8DBQFQeAheUxlJ7aRr7hoRAibDAJ9yAfiSwNmh8R4tGwUIwFEZno2qWACfStCM >> y+xKb+FGGglmv8lTL9Ej8ZQ= >> =ub/P >> -----END PGP SIGNATURE----- > >
