Synchrotron Champions - Nathan Cowieson and Matthew Wilce

Powder Diffraction a New Technique to Solve Protein Structures

Doctors Matthew Wilce and Nathan Cowieson, from the department of Biochemistry and Molecular Biology recently showed that the powder diffraction beamline at the Australian Synchrotron is suitable for solving the structure of proteins.

The data collected by the Monash researchers in a proof-of-concept experiment using lysozyme; a protein commonly used as a test-case in crystallography experiments, produced surprising results. Crystal diffraction data from a single crystal is generally measured in several hundred images. In contrast, powder diffraction data is measured from many thousands of tiny crystals in a single image. In this experiment a thirty minute exposure was sufficient to measure diffraction data from lysozyme to high resolution, enabling protein structure determination.

Dr Cowieson, Beamline Research Fellow for the Monash Centre for Synchrotron Science is impressed with the results, and wants other Monash researchers to become aware of the beamline's capability.

"If you are unable to grow large suitable crystals for protein crystallography, it's now possible to pool the small crystals together and analyse them using the powder diffraction technique at the Australian Synchrotron."

"The outcome of this experiment demonstrates that the powder diffraction beamline is capable of achieving excellent angular resolution and rapid data collection, as well as reducing radiation damage to samples, which is unachievable with more common techniques." Dr Cowieson said.

Monash researchers have an allocation of beam time as one of the 11 Foundation Investors who funded the initial suite of nine beamlines. Dr Cowieson and his colleagues intend to make use of this, by applying for more powder diffraction beam time at the Australian Synchrotron in 2009 to determine the structure of an important biological protein involved in binding toxins, such as dioxin.