X-Message-Number: 25194
From: "Basie" <>
Subject: 'Ultra-Cold Neutron Protein Crystallography' 
Date: Wed, 1 Dec 2004 19:30:56 -0500

One day they will use this technique to pin point every atom in the frozen 
brain.

Basie

Source:   University Of Manchester

University Of Manchester Uses Crystals To Help Battle Deadly Diseases
A groundbreaking technique developed at The University of Manchester, which 
uses crystals to map 'invisible' parts of molecules, is set to revolutionise 
drug discovery.
The technique, which involves sending beams of neutrons through crystals at 
freezing temperatures, just a few degrees above 'absolute zero', will for 
the first time allow scientists to see complete structures of protein 
molecules, right down to the last atom.

The problem faced by scientists using current methods is the fact that it is 
not possible to detect every atom in a protein's molecular structure, and 
the structures therefore are incomplete - making drug design more difficult.

Professor John R. Helliwell, Professor of Structural Chemistry, who led the 
research, said: "This has raised the stakes in the world of drug discovery. 
This methodology will make research in the field more powerful, more 
effective and more efficient."

The breakthrough allows the molecular structures of proteins, the chemical 
catalysts in the body, to be studied in complete detail. In fact, 
experiments at the University have shown that the number of visible atoms in 
a molecule doubled when using the technique, compared to techniques used 
today.

Protein Crystallography is an important tool used to determine the 
three-dimensional structures of proteins. Once a pharmaceutical company has 
this information, it is able to tailor drugs to target specific proteins, eg 
interfering with the function of such proteins in infectious agents like 
tuberculosis - enabling the production of more effective medicines.

'Ultra-Cold Neutron Protein Crystallography' improves on current methods by 
probing protein structures with neutrons at temperatures of 15K (-258 
degrees C), dramatically increasing the number of visible atoms. The process 
especially reveals the hydrogen atoms, which hold the key to many chemical 
reactions, and because of their low mass, are rarely revealed by current 
methods like X-Ray Crystallography even if carried out at freezing 
temperatures.

Professor Helliwell added: "As well as the above advantages this makes other 
classes of experiments on proteins feasible. In particular, the comparison 
of protein structures at ultra-cold versus room temperature allows the 
details of atomic vibrations to be separated from structural disorders."

"Another benefit to research that now becomes possible is that chemical 
reactions can be set running directly in the crystal and then freeze-trapped 
so as to probe the proteins in time with the neutron beam whilst the protein 
is actually in its functional state."

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