Thursday, 22 November 2012

WA Chemistry Prof wins Aminoff prize for molecule research

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x ray_crystalThe program, called CrystalExplorer, can then generate a theoretical boundary around each molecule in the crystal matrix—effectively showing where one ends and the next one begins. Image: CrystalExplorerA UNIVERSITY of WA chemistry professor has become the first Australian to win a prestigious international prize for his work in uncovering the inner workings of crystalline molecules such as pharmaceutical drugs.

Mark Spackman, head of UWA's School of Chemistry and Biochemistry, has been awarded the Aminoff Prize in Crystallography for designing a new way to visualise how molecules fit together to form crystals.

He developed his theory into a software program that allows other researchers to more easily study crystalline molecules. 

Professor Spackman, who first began work this area in 1996, says learning how molecules stick together in the way they do has "ramifications in all sorts of areas" of chemistry.

One example is in pharmaceuticals. The information could be used to help drug companies protect their patents, by showing exactly how drug molecules are arranged when the compounds are in their solid form—the most usual way of delivering drugs.

"To protect their intellectual property, [drug companies] need to know not just what they have, but if there are any other crystalline forms of it," Prof Spackman says.

Not covering their bases in this way could allow a rival company to market a chemically identical drug with a slightly different crystal arrangement.

Chemists deduce a substance's molecular structure by firing beams of X-rays at it - a process called X-ray crystallography. Different molecules scatter the X-rays in different patterns.

Figuring out how those molecules fit together to form larger crystals used to involve poring over charts, tables, and data on the lengths and angles of various atomic bonds.

That's where Prof Spackman's work comes in. Using WA supercomputing provider iVEC’s infrastructure, he developed a software program that takes X-ray crystallography data and spots areas where the electron density is lower—in a sense, the 'gaps' between molecules.

The program, called CrystalExplorer, can then generate a theoretical boundary around each molecule in the crystal matrix—effectively showing where one ends and the next one begins.

Known as the 'Hirshfeld surface', this boundary can be used to visualise how the molecules fit together, rather like looking at how the individual chambers of a honeycomb form a larger pattern.

Prof. Spackman first demonstrated the technique using small, simple crystals such as urea. But it works "all the way from very simple molecules, right up to proteins and enzymes", he says.

The award will be presented by Sweden's King Carl Gustav at a ceremony at the Royal Swedish Academy of Sciences on 5 April 2013.

Prof Spackman will share the 100,000 krona (AU$14,200) prize with Italian researcher Carlo Gatti of the Institute of Molecular Sciences and Technology in Milan, who has made similar strides in interpreting X-ray crystallography.

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