Re: [ccp4bb] AW: [ccp4bb] removal of sulfate ion from the active site

- Protein crystallography

Main steps:

- Protein purification
- Crystallisation

Special:

- Programs for crystallography
- X-ray detectors

Basic tutorials:

   - Chemistry
   - Protein
   - Peptide
   - Amino Acids

Xtal community:

- CCP4BB

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

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Subject: CCP4i unable to extract data from Project directory
From: Jhon Thomas jhon1 {- dot -} thomas {- at -} GMAIL {- dot -} COM
Date: 2007-05-25

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Date: 2007-05-25

Subject: Re: AW: removal of sulfate ion from the active site
From: Marius Schmidt marius {- dot -} schmidt {- at -} PH {- dot -} TUM {- dot -} DE
Date: 2007-05-25

think about your old chemical kinetics courses.
what counts is concentration and not amount.

M

> Dear Marius and others,
> here I would like to comment: The problem with soaking is often not
> so much the concentration of the ligand, but the amount of ligand
> needed to fill all binding sites in the crystal. A typical crystal
> contains about 20 mM protein so one has to add the equivalent amount
> of ligand. On the other hand, the concentration UNBOUND inhibitor,
> asuming a 1:1 protein-ligand complex, need only to be in the order of
> 10-100 times the Kd (90-99% occupancy). Ways to overcome this is to
> soak in a large volume of mother liquor (containing a large amount of
> ligand) or to add solid ligand to the mother liquor and let the
> ligand slowly dissolve and diffuse into the crystal.
>
> Herman
>

CCP4bb navigation

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

Previous message:
Subject: CCP4i unable to extract data from Project directory
From: Jhon Thomas jhon1 {- dot -} thomas {- at -} GMAIL {- dot -} COM
Date: 2007-05-25

Next message:
Subject: Post Doctoral Position: Microfluidic Protein Crystallization, University of Chicago
From: Jessica Price ismagilovlab {- at -} UCHICAGO {- dot -} EDU
Date: 2007-05-25