The Imaging CoE is committed to bringing experts together to work on and solve some of the biggest questions in advanced molecular imaging. A recent collaboration between two Australia-based researchers is a shining example of this synergy in action.
CoE researcher Connie Darmanin, La Trobe University, and CoE AI Bostjan Kobe, University of Queensland, worked closely to develop a deeper understanding of how to handle, characterise and produce nanocrystals.
Why is this a big deal?
It’s because beamtime at an XFEL is a scarce and precious commodity, and being able to determine the quality of nanocrystals for Serial Femtosecond Nanocrystallography (SFX) experiments using local resources is critical in developing successful bids for access to beamtime at these cutting-edge facilities.
In an article published in Nature Scientific Reports in May, Darmanian and Kobe outline a new protocol for testing nanocrystals prior to applying for XFEL beamtime. Darmanian explains why this new protocol is important:
“Nanocrystallography and XFELs are at the cutting edge of X-ray scientific research and enormous efforts are being devoted to translating these technologies into a useful tool for structural biologists. Whenever there are fundamental advancements in X-ray sources, such as the development of the first synchrotrons, there are many unknowns that need to be solved and a lot of research needs to be conducted into what does and doesn’t work.”
When Darmanian heard that Kobe had obtained beautiful crystals that were, unfortunately, too thick for electron diffraction and too small for conventional synchrotron crystallography, she knew the pain he was feeling all too well.
“There are two main challenges my lab faces: handling and characterising nanocrystals that are too small to be viewed in optical microscopes and producing a sufficient quantity of nanocrystals for use with SFX,” she explains.
People the globe over are facing the same problems. And with high demand for access to the two XFELs currently in operation, anything that is able to increase the odds of capturing high resolution data is of enormous benefit to the entire community.
In this case, instead of letting Kobe’s crystals go to waste, Darmanian was inspired to pool their expertise, characterise the crystals, determine whether or not they were sufficiently crystalline for X-ray analysis, and see if they were suitable for SFX measurement.
The collaboration between the two CoE nodes combined data from several biophysical characterisation techniques including light microscopy, transmission electron microscopy, dynamic light scattering and synchrotron imaging. They looked at the size, the quality and the ordering of the crystals – the three most significant factors that influence the success of XFEL experiments.
Darmanian hopes the work will help other researchers wanting to use nanocrystallography — within the Imaging CoE and in the wider community — to carry out experiments for protein structure determination.
“In developing the protocols we published, I drew upon a range of biophysical techniques and my experience over the past 10 years as a protein crystallographer,” she says. “We have since leveraged the work presented in this Nature publication into beamtime at the Stanford XFEL (the Linac Coherence Light Source), where we collected preliminary data out to three angstrom resolution. We are currently working on developing this into a full proposal to collect a complete dataset and are using this project to help bring in the support of our collaborators from our partner centre at DESY in Hamburg.”
In addition to creating a new protocol for testing nanocrystals, Darmanian says the collaboration between the University of Queensland and La Trobe University nodes brings us a step closer to understanding the health issues associated with inflammatory disease.
“By combining my expertise in nanocrystallography with Kobe’s passion for understanding the fundamental biochemical and biophysical origins of inflammatory disease, we have developed new techniques for molecular imaging – that’s what drives me,” Darmanian concludes.
Read the article online: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4853777/
