By Bill Bruton
Published March 20, 2023
Thomas D. Grant, PhD, assistant professor of structural biology, is part of a research team that is helping to lead the development of X-ray scattering and data analysis at the compact X-ray free electron laser (CXFEL).
The U.S. National Science Foundation announced on March 8 that it was providing $90.8 million in funding to Arizona State University (ASU) to create the CXFEL facility. Of that, Grant will receive $128,143 over five years for his research. The investment is a component of NSF’s ongoing support for cutting-edge science and engineering research infrastructure to support innovative research.
Part of Grant’s research involves helping to design “endstations,” which is where the X-rays are emitted, in particular for biological studies.
“The X-rays are used to probe the atomic structures and dynamics of biological samples, such as proteins and viruses. More specifically, the endstation that I am helping to design will be used for performing experiments called time-resolved solution X-ray scattering and time-resolved serial femtosecond crystallography,” Grant says.
In biology, X-ray scattering and serial femtosecond crystallography are used to determine the atomic 3D structures of biological molecules such as proteins and viruses.
“The ‘time-resolved’ part of these experiments is that in addition to getting ‘static’ structures of molecules, we will also be triggering chemical reactions in the proteins and watching the subsequent motions take place with extremely fine time resolution (femtoseconds), the ‘dynamics’ part,” Grant says. “It’s kind of like the difference between taking a picture and recording a movie. With time-resolved X-ray scattering and time-resolved serial femtosecond crystallography, we can watch movies of ultrafast catalytic reactions inside proteins to learn what motions take place to understand how they work.”
Grant says you should think of it like a very complicated Rube Goldberg machine. Taking one picture of that complicated sequence of events is helpful, but certainly will not tell you enough information about how it works. However, if you could record a movie of each and every event and how it triggers the next event (which is similar to how each and every individual atom in a protein moves and interacts with other atoms to carry out the protein’s function), then you would have a much better understanding of how the machine works.
“That’s the advantage of the CXFEL, telling us detailed information about how each part of the reaction sequence occurs as the protein carries out its function,” he says.
Additionally, Grant is developing new software for analyzing and modeling the extremely large quantities of data that will be produced by the CXFEL, including using new artificial intelligence algorithms.
“Most of my time will be at the computer here at the Jacobs School of Medicine and Biomedical Sciences. However, I will travel to ASU regularly to perform the experiments in person, and if possible, remotely from UB,” Grant says.
He plans to use the unique features of the CXFEL to study the structure and dynamics of biological molecules such as proteins.
“Large XFELs — first built in 2009 — have transformed our ability to study these protein motions and dynamics and understand how they function at a much greater level with atomic resolution and femtosecond time scales (one millionth of a billionth of a second, as fast as atoms can move),” Grant says.
However, Grant says, large XFELs are typically miles in length and cost billions of dollars to build and operate, and there is currently only one in operation in the U.S., and only a handful worldwide.
“The scarcity of XFELs makes it very difficult for scientists to be able to obtain time on these machines, meaning much of the potential applications and benefits of the technology is unrealized,” he says. “Recent technologies developed by scientists at ASU have enabled the creation of compact XFELs that are as fast as the big XFELs — but not as bright — and are small enough to fit into the basement of a building at ASU, costing 10 or 20 times less than what the large XFELs do.”
The CXFEL at ASU will be the world’s first of its kind. Research groups from all institutions can apply for time to perform experiments at the CXFEL. However, UB is one of 16 institutions that are part of CXFEL itself in terms of its development, and Grant will be involved in designing and carrying out the first experiments — hopefully this summer — and many more in the future.
“The CXFEL will develop this technology to provide the groundwork for getting many compact XFELs up and running around the world and this will enable many more scientists to take advantage of XFEL technology,” Grant says.
The Midscale Research Infrastructure-2 awards support projects with scientific merit that have a modest footprint with a large impact and address scientific or societal concerns. The program supports mid-scale research infrastructure, including facilities, networks, equipment, datasets and staff.