Re: [ccp4bb] recommendation for heavy atoms used in lithium sulfate and ammonium sulfate

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CCP4bb <-- 1999 <-- November 1999 <-- 30 November 1999

Previous message:
Subject: recommendation for heavy atoms used in lithium sulfate and ammonium sulfate
From: Tiancen Hu tony_htc {- at -} 126 {- dot -} COM
Date: 2007-04-19

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From: o {- dot -} h {- dot -} weiergraeber {- at -} FZ-JUELICH {- dot -} DE o {- dot -} h {- dot -} weiergraeber {- at -} FZ-JUELICH {- dot -} DE
Date: 2007-04-20

Subject: Re: recommendation for heavy atoms used in lithium sulfate and ammonium sulfate
From: Ronnie Berntsson r {- dot -} berntsson {- at -} RUG {- dot -} NL
Date: 2007-04-20

Hi Tiancen,

I can recommend using a Halide soak (bromide or iodine). You could
try to "exchange" part your salt with sodium bromide. Always use a
bad looking crystal for the first soak though to see that it doesn't
get damaged by the soak.

See for further reference:
Novel approach to phasing proteins: derivatization by short cryo-
soaking with halides
Z. Dauter, M. Dauter and K. R. Rajashankar
Acta Cryst. (2000). D56, 232-237

Cheers,
Ronnie Berntsson

On Apr 20, 2007, at 6:26 AM, Tiancen Hu wrote:

> Dear all,
>
> Could any one recommend some heavy atoms used for crystals grown in
> 0.1M tri-sodium citrate pH 5.6, 1M Lithium sulfate and 0.5M
> ammonium sulfate? I read from Hampton user guide of heavy atom kit
> that "high salt concentrations are not the ideal medium for heavy
> atom reactions with macromolecules", so is there any type of heavy
> atom we should avoid using? We do not have any experience in
> preparing heavy atom derivative, so any suggestions, experience or
> references will be greatly appreciated.
>
> Thanks in advance!
>
> Tiancen Hu
> Shanghai Institute of Materia Medica

Ronnie Berntsson

----------
Ph.D. Student
Department of Biochemistry
Groningen Biomolecular Sciences and Biotechnology Institute
& Zernike Institute for Advanced Materials
University of Groningen
Nijenborgh 4, 9747 AG
Groningen, The Netherlands

telephone: +31 50 363 4195
telefax: +31 50 363 4165
e-mail: r.berntsson@rug.nl
homepage: http://www.rug.nl/gbb/research/researchgroups/enzymology/index

CCP4bb navigation

CCP4bb <-- 1999 <-- November 1999 <-- 30 November 1999

Previous message:
Subject: recommendation for heavy atoms used in lithium sulfate and ammonium sulfate
From: Tiancen Hu tony_htc {- at -} 126 {- dot -} COM
Date: 2007-04-19