In our protein crystallography course, we succesfully used S-SAD phasing for proteinase K crystals diffracting to 1.58 Å (which is 'low' for these crystals) at our home source.
I would highly recommend using proteinase K for heavy atom derivative demonstration purposes as it seems much easier to produce these for proteinase K than for lysozyme. In our hands quick soaks (i.e. a few minutes) in 50 mM stocks of e.g. EuCl3 or SmCl3 (Eu works great because of the strong anomalous signal at the Cu Ka edge) are fine. Our course is based on course material from UCLA: http://www.doe-mbi.ucla.edu/~sawaya/m230d/m230d.html If you are interested, you are welcome to contact me ([EMAIL PROTECTED]) for our teaching material. Cheers, Thomas -- Thomas Boesen Associate Professor, PhD Centre for Structural Biology Department of Molecular Biology University of Aarhus Gustav Wieds Vej 10C 8000 Århus C Phone: +45 8942 5257 (lab: +45 8942 5030) E-mail: [EMAIL PROTECTED] web: http://www.bioxray.au.dk/index_uk.php what is it that you want to demonstrate? If it is just for structure solution, would S-SAD phasing be an option? That way all you need is a crystal, probably diffracting to better than, say, 2A. And a little bit of multiplicity. I assume this is feasible for Lysozyme whereas I don't know the diffraction qualities of proteinase K crystals. Tim -- Tim Gruene Institut fuer anorganische Chemie Tammannstr. 4 D-37077 Goettingen GPG Key ID = A46BEE1A On Tue, 23 Sep 2008, Tommi Kajander wrote: Hi, Could anyone give a more or less exact recipee for preparing a derivate for lysozyme or proteinase K? like what used, concentration and soak time. we'd need some data sets for a lab course only thing that really worked so far was lysozyem KI SIRAS (which however doesnt seem to be good enough for demonstration purposes, so we need more) Thanks very much! best, Tommi Tommi Kajander, Ph.D. Structural Biology and Biophysics Institute of Biotechnology University of Helsinki Viikinkaari 1 (P.O. Box 65) 00014 Helsinki Finland p. +358-9-19158903 [EMAIL PROTECTED] ---------------------------------------------------------------- This message was sent using IMP, the Internet Messaging Program.
