For HEW lysozyme: precipitant is 2 to 6 % (w/v) NaCl in 0.2 M Na acetate
pH 4.7 (the recommended procedure is to prepare a stock solution of 10%
NaCl). For the derivative, use para-chloro mercuri benzene sulphonic
acid. In 15 ml of the above stock solution, dissolve 0.123g of PCMBS.
Then use at 2 to 6% NaCl. Normally the crystals should grow within 24 to
48 hours.
They are not completely isomorphous with the native crystals though but
this might be sufficient for a course.
Fred.
Patrick Loll wrote:
> Hi,
>
> Does anyone have a foolproof recipe for preparing one or more heavy
> atom derivatives for a nice, easily crystallized protein like
> lysozyme? I'm looking for something that I can use as a hands-on
> MIR/SIR tutorial for beginning students. I'd rather the students be
> able to focus their attention on data collection and analysis, rather
> than spending a lot of time screening different soaks.
>
> I have looked at Peter Sun's paper on quick soaking (Acta Cryst D58:
> 1092-1098, 2002), and will definitely try what they did; but any other
> recipes would also be welcome.
>
> Thanks,
>
> Pat
>
>
> ---------------------------------------------------------------------------------------
>
> Patrick J. Loll, Ph. D.
>
> Professor of Biochemistry & Molecular Biology
>
> Director, Biochemistry Graduate Program
>
> Drexel University College of Medicine
>
> Room 10-102 New College Building
>
> 245 N. 15th St., Mailstop 497
>
> Philadelphia, PA 19102-1192 USA
>
>
> (215) 762-7706
>
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>
>
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