Re: [ccp4bb] heavyatom soaking problem

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

Previous message:
Subject: Re: heavyatom soaking problem
From: "Mark A {- dot -} White" white {- at -} XRAY {- dot -} UTMB {- dot -} EDU
Date: 2007-06-29

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From: Tassos Papageorgiou apapageo {- at -} BTK {- dot -} UTU {- dot -} FI
Date: 2007-06-29

Subject: Re: heavyatom soaking problem
From: "Sanishvili, Ruslan" rsanishvili {- at -} ANL {- dot -} GOV
Date: 2007-06-29

Hi,
I assume Se-Met is not possible for your protein?
You don't say how well (or poorly) your native crystals diffract.
Increasing number of people are getting their phases by S SAD.
With such affinity to high NaCl concentrations, you could also try high
salt (NaCl, NaBr, RbBr etc,) soaks for phasing.
Good luck,
Nukri

Ruslan Sanishvili (Nukri), Ph.D.

GM/CA-CAT, Bld. 436, D007
Biosciences Division, ANL
9700 S. Cass Ave.
Argonne, IL 60439

Tel: (630)252-0665
Fax: (630)252-0667
rsanishvili@anl.gov

-----Original Message-----
From: CCP4 bulletin board [mailto:CCP4BB@JISCMAIL.AC.UK] On Behalf Of
Priyank Maindola
Sent: Thursday, June 28, 2007 12:28 PM
To: CCP4BB@JISCMAIL.AC.UK
Subject: [ccp4bb] heavyatom soaking problem

Hello all,
I am struggling with getting the phases out for my protein. Heavyatom
database shows that only mercury and samarium have the binding motifs in
it.

Sodium iodide soak is killing the crystal even as less as 0.2 Molar
concentration for 30sec.
With Potassium iodide crystal is okay upto 0.75M for 1 & a half min but
the incorporation is not at relevent sites.(Iodide signal is not
distinct and is weak) Hg & Au salts precipitate it.
With Pt signal is weak.
Somewhere I read that high salt causes problems for heavy atom to bind
to protein.My protein needs high salt for stability (750mM NaCl)

Please help with some suggestion!!

CCP4bb navigation

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

Previous message:
Subject: Re: heavyatom soaking problem
From: "Mark A {- dot -} White" white {- at -} XRAY {- dot -} UTMB {- dot -} EDU
Date: 2007-06-29

Next message:
Subject: Re: packing
From: Tassos Papageorgiou apapageo {- at -} BTK {- dot -} UTU {- dot -} FI
Date: 2007-06-29