Re: [ccp4bb] Malic Acid interferes heavy metal binding?

Protein crystallography Programs for crystallography X-ray detectors
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CCP4bb <-- 2008 <-- January 2008 <-- 09 January 2008

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Subject: Crystal imaging system
From: Alexander Aleshin aaleshin {- at -} BURNHAM {- dot -} ORG
Date: 2008-01-09

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From: Bernhard Rupp bernhardrupp {- at -} SBCGLOBAL {- dot -} NET
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Subject: Re: Malic Acid interferes heavy metal binding?
From: Artem Evdokimov artem {- at -} XTALS {- dot -} ORG
Date: 2008-01-09

Hi,

Heavy atoms can be unpredictable. There are rules of thumb regarding their
use but these rules are frequently bent and broken.

Which heavy atom derivatives have you tried, and at what (approximately)
concentrations and exposure times? Does your protein have residues that
*can* react with HA compounds? What do you mean when you say 'no success' -
do the crystals survive unperturbed, or do they always die?

There almost always is a derivative for you out there, but sometimes you
have to spend time looking. If you have tyrosine residues in relative
abundance you can always try iodination (let me know if you want a good
working protocol), etc.

More details would let us help you better!

Artem

_____

From: CCP4 bulletin board [mailto:CCP4BB@JISCMAIL.AC.UK] On Behalf Of JINJIN
ZHANG
Sent: Wednesday, January 09, 2008 6:42 PM
To: CCP4BB@JISCMAIL.AC.UK
Subject: [ccp4bb] Malic Acid interferes heavy metal binding?

Dear All,

I have got large and nice crystals in a condition that contains 40%
glycerol, 75 mM DL-Malic Acid pH7.0, and that's it! No precipitant?! No
buffer?! I'm so comfused. As far as from the product website, the Malic Acid
has no buffering function. I don't know whether it's a precipitant. The
protein itself was stored in a buffer contains 20mM Tris pH7.5, 150mM NaCl
and 10% glycerol. I'm having difficulties in getting heavy metal bound
derivatives. I was wondering whether the Malic Acid interferes heavy metal
binding? Does anyone has any success with crystals grow with similar
conditions? Any comment and suggestion is highly appreciated.

Regards,

Jinjin Zhang

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CCP4bb <-- 2008 <-- January 2008 <-- 09 January 2008

Previous message:
Subject: Crystal imaging system
From: Alexander Aleshin aaleshin {- at -} BURNHAM {- dot -} ORG
Date: 2008-01-09

Next message:
Subject: Re: Crystal imaging system
From: Bernhard Rupp bernhardrupp {- at -} SBCGLOBAL {- dot -} NET
Date: 2008-01-09