Re: [ccp4bb] which concentrated salt has lowest vapour pressure?

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

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Subject: Re: which concentrated salt has lowest vapour pressure?
From: David Briggs drdavidcbriggs {- at -} GMAIL {- dot -} COM
Date: 2008-04-07

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Subject: Re: which concentrated salt has lowest vapour pressure?
From: "George M {- dot -} Sheldrick" gsheldr {- at -} SHELX {- dot -} UNI-AC {- dot -} GWDG {- dot -} DE
Date: 2008-04-07

Li salts tend to increase the solubility of peptides (Seebach et al.,
Helv. Chim. Acta 72 (1989) 857-867), which is a pity, because they can
also be used as cryoprotectants.

George

Prof. George M. Sheldrick FRS
Dept. Structural Chemistry,
University of Goettingen,
Tammannstr. 4,
D37077 Goettingen, Germany
Tel. +49-551-39-3021 or -3068
Fax. +49-551-39-2582

On Mon, 7 Apr 2008, Kay Diederichs wrote:

> Dear all,
>
> a protein which we work on is available in low quantity. The only
> crystallization screen we set up is completely clear, no precipitate, nothing.
>
> Now we would like to modify the reservoirs of this screen, by adding LiCl or
> Ammoniumsulfate or ... , with the goal of reducing the vapour pressure, to at
> least get the protein concentration in the drop into the range where
> "something happens".
>
> Does anyone have advice as to which salt we should add (to the reservoir
> only)? AmSO4 is only soluble to 4M, LiCl goes to 10M. But vapour pressure
> reduction is not the same as molarity.
>
> thanks for any insight,
>
> Kay
> --
> Kay Diederichs http://strucbio.biologie.uni-konstanz.de
> email: Kay.Diederichs@uni-konstanz.de Tel +49 7531 88 4049 Fax 3183
> Fachbereich Biologie, UniversitÃ¤t Konstanz, Box M647, D-78457 Konstanz
>
>

CCP4bb navigation

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

Previous message:
Subject: Re: which concentrated salt has lowest vapour pressure?
From: David Briggs drdavidcbriggs {- at -} GMAIL {- dot -} COM
Date: 2008-04-07

Next message:
Subject: Re: DM - NCS averaging after phaser molecular replacement run-confused about coefficients
From: hari jayaram harijay {- at -} GMAIL {- dot -} COM
Date: 2008-04-07