My usual first approach to increasing crystal size is to decrease
precipitant and increase protein concentration, keeping the mixture in
the proper nucleation zone, but providing more protein for crystal
growth. Minimizing dust or particulates by filtration and centrifugation
of reagents and protein may help, by reducing nucleation sites in the
solution. Crystallization at a lower temperature may also result in
fewer, but larger crystals. Or you could try seeding.
Cheers,
--
------------------------------------------------------------------------
Roger S. Rowlett
Professor
Colgate University Presidential Scholar
Department of Chemistry
Colgate University
13 Oak Drive
Hamilton, NY 13346
tel: (315)-228-7245
ofc: (315)-228-7395
fax: (315)-228-7935
email: [EMAIL PROTECTED]
Walter Novak wrote:
Hi Vince,
There is a very nice paper by Monika Budayova-Spano in Acta Cryst 63D
2007 339-347. "A methodology and an instrument for the
temperature-controlled optimization of crystal growth."
Best,
Wally
On Sep 10, 2008, at 2:23 AM, Vincenzo Carbone wrote:
Dear all,
I was wondering if anyone had some practical advice in regards to
increasing the size of a crystal. Currently my enzyme forms these
rather nice cubic and very sharp <0.1mm (in 25% peg 5000, 0.1M
ammonium sulphate, 0.1M Tris ph 7.0) crystals following optimisation
of the pH and precipitant concentrations of the initial screening
condition and by playing with various increasing levels of protein
concentration 20-60mg/ml.
Has anyone had success with additive screens in increasing crystal
size and what were they?
Any advice would be useful thanks
Vince
Walter R.P. Novak, Ph.D.
Postdoctoral Fellow
Rosenstiel Basic Medical Research Center
Brandeis University
415 South St. MS 029
Waltham, MA 02454-9110
Phone: (781) 736-4944
Fax: (781) 736-2405
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