Re: [ccp4bb] Crystal rescue

- 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

Previous message:
Subject: Crystal rescue
From: Zhiyi Wei ustcwebridge {- at -} GMAIL {- dot -} COM
Date: 2010-01-26

Next message:
Subject: Re: Crystal rescue
From: Ed Pozharski epozh001 {- at -} UMARYLAND {- dot -} EDU
Date: 2010-01-26

Subject: Re: Crystal rescue
From: Ezra Peisach epeisach {- at -} GMAIL {- dot -} COM
Date: 2010-01-26

First you need to establish if it is your cryo conditions or the
crystals. Depending where you are - they might have the equipment to do
a wet mount - without freezing. Yes the crystal will not last - but
then you know if the problem is in the
crystal. If it is - you need better crystals. If it is the cryo - you
need to work on that. Tacsimate is mixture of alot of different
compounds - but the smears are too close together to be a small salt
crystal on top...

Good luck,

Ezra

On 1/26/2010 10:42 AM, Zhiyi Wei wrote:
> Dear all,
>
> I got a problem with my crystals. I have two total different proteins
> that both can be crystallized in the condition with PEG3350 and Tacsimate
> (although the concentrations are different) with different shapes. The
> crystals look big and beautiful. However, when I test them in synchrotron,
> both of these two types of crystals showed poor diffractions. As showed in
> the attached diffraction image, the diffraction is up to ~4 A but smear in
> one direction while<8 A in the other direction. The interesting thing is
> that the diffraction pattern is similar for all crystals (from two different
> proteins) that I tested without exception although they belong to different
> space groups. So, I wonder whether these kind of pattern is caused by
> Tacsimate (I don't know what it is) and how to rescue these crystals. Any
> suggestions or comments?
>
> Thanks a lot!
>
> Best,
> Zhiyi
>

CCP4bb navigation

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

Previous message:
Subject: Crystal rescue
From: Zhiyi Wei ustcwebridge {- at -} GMAIL {- dot -} COM
Date: 2010-01-26

Next message:
Subject: Re: Crystal rescue
From: Ed Pozharski epozh001 {- at -} UMARYLAND {- dot -} EDU
Date: 2010-01-26