-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Dear Sarah,
it is very common that SeMet preps behave differently from the native crystal w.r.t. the crystallisation conditions, and 13Mets for a 43kDa protein is a lot! Don't judge a book by its cover: The only way to find out whether your differently shaped crystals diffract is to test them on an X-ray machine. Until you have done so you do not even know whether you have a "SeMet-Problem". Have you tried micro-seeding from the native crystals into a drop with SeMet-protein? Tim On 04/17/12 09:58, Qian Sarah wrote: > Hi, I'm now facing a problem about selenomethionine-labelled > protein crystallization.. Native protein crystallized very well and > diffracted to 2.5A. However, SeMet-protein expression level > decreased to only 1/10, and its crystals have different shape with > before(native protein crystals have beautiful rhombohedral shape, > while SeMet-protein crystals have a shuttle shape). For another > crystalllization condition the SeMet protein don't crystallize at > all while the native protein got crystals with even higher > resolution. I don't know whether these "shuttle shaped" crystals > are worthy to be used or not? But there are only 13 Met in my > protein (43KD), why they have so much difference? Is this common, I > mean, the huge difference between SeMet and native protein > crystallization? And, any suggestions about what I can try to > solve this Se-Met problem? (What I'm doing now is to screen > crystallization kit with SeMet protein.) > > Thank you very much for your help! best, Sarah > - -- - -- 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/ iD8DBQFPjTTGUxlJ7aRr7hoRAoW+AJ9AquRYnXbaXfGl7MiRVMQ0KRaomQCfZ3NW 8GUTky+3a5/CS795RbqGDHI= =tgAe -----END PGP SIGNATURE-----
