Re: [ccp4bb] protein or salt?

- Protein crystallography

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

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Subject: Position for Structural Biologist-Novartis Institutes for BioMedical Research
From: "Bussiere, Dirksen" dirksen {- dot -} bussiere {- at -} NOVARTIS {- dot -} COM
Date: 2007-04-18

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Subject: Re: protein or salt?
From: Frank von Delft frank {- dot -} vondelft {- at -} SGC {- dot -} OX {- dot -} AC {- dot -} UK
Date: 2007-04-18

Subject: Re: protein or salt?
From: Artem Evdokimov artem {- at -} XTALS {- dot -} ORG
Date: 2007-04-18

Hi,

In my opinion this is clearly a twinned crystal of some sort of a small
molecule. If you have a small ice crystal on top of a completely
non-diffractive protein crystal, sometimes the pattern may also look like
this - but I would bet this is just 'salt'.

Artem

_____

From: CCP4 bulletin board [mailto:CCP4BB@JISCMAIL.AC.UK] On Behalf Of Noinaj
Sent: Wednesday, April 18, 2007 7:19 PM
To: CCP4BB@JISCMAIL.AC.UK
Subject: [ccp4bb] protein or salt?

Hi,

i collected a diffraction pattern today of a protein crystal, hoping to
answer the question, is it a protein or salt? The crystals appear as
typical proteins crystals (from my experience), forming both plates and
rods, easily crushed into millions of tiny crystals, and are bouyant.
unfortunately, i collected a diffraction pattern that is a bit confusing.
you can see the image at the following URL:

http://www.noinaj.com/temp/screen1.jpg

while i don't see very low resolutions spots, i do see spots lower than 4
ang; it seems nothing is available for lower resolution than that. does
this indicate salt (despite properties screening), which I thought would
only show high resolution spots, and only a few, not as many as observed in
the image.

Essentially, could anyone offer any further analysis of the diffraction
pattern and help me decide whether this is a protein or salt? Thanks in
advance for all feedback!!!

Cheers,

Nick

________________________________________

Nicholas Noinaj
University of Kentucky School of Medicine
Department of Molecular and Cellular Biochemistry
Biomedical Biological Sciences Research Building, Rm 236
741 S. Limestone
Lexington, Ky 40536
Lab: 859-323-8183
Home: 859-228-0978
noinaj@uky.edu
www.noinaj.com

CCP4bb navigation

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

Next message:
Subject: Re: protein or salt?
From: Frank von Delft frank {- dot -} vondelft {- at -} SGC {- dot -} OX {- dot -} AC {- dot -} UK
Date: 2007-04-18