Ritimukta "Riti" Sarangi, a senior scientist at the Department of Energy's SLAC National Accelerator Laboratory, is the latest recipient of the Farrel W. Lytle Award, which recognizes important contributions to synchrotron science and efforts to support users at the Stanford Synchrotron Radiation Lightsource (SSRL), a DOE Office of Science user facility.
Since its inception in 1998, the Farrel W. Lytle Award has been given annually to SSRL staff members and users from around the world.
"Farrel is a legend in X-ray spectroscopy science. He has made contributions to every aspect of X-ray instrumentation, measurement and analysis," Sarangi said. "I was completely unaware of my nomination and was thrilled when I received the email" notifying her of the award.
Sarangi started running experiments at SSRL in 2001, when she was a graduate research assistant at Stanford University. After earning her PhD in chemistry, she joined the SSRL staff in 2007. She is currently a senior member of the Structural Molecular Biology group at SSRL and a hard X-ray spectroscopist.
In a nomination letter for the award, Graham George, the Canada research chair in X-ray absorption spectroscopy at the University of Saskatchewan, praised Sarangi's contributions in research, user support, outreach and leadership. "While SSRL scientific staff includes many outstanding individuals, even among this strong competition Riti stands out," he wrote. "I have heard Riti described by senior SSRL management as an 'anchor at SSRL,' and I think that this description is an accurate one."
Catalyzing discoveries
Sarangi uses X-ray spectroscopy techniques to study the fundamental properties of enzymes, molecules produced by a living organism that act as a catalyst to bring about specific biochemical reactions. Much of her research focuses on metalloenzymes, a broad group of enzymes with one or more metal ions in their active site, where other molecules bind and undergo a chemical reaction.
"Metalloenzymes perform a wide range of chemical transformations from electron transfer to small molecule activation to more complex molecular transformations," explained Sarangi. "My goal is to apply X-ray methods towards understanding the structural and electronic details of these metal-containing active sites to shed light on the functional details of metalloenzymes and related systems."
She is particularly interested in understanding methyl coenzyme M reductase (MCR), a unique nickel-containing enzyme responsible for the generation of 1 billion metric tons of methane annually.
Methane is the main component of natural gas and accounts for almost a quarter of U.S. energy consumption, but it is also a potent greenhouse gas. Understanding the mechanistic aspects of methane activation and synthesis is, therefore, imperative from fundamental, applied-energy, economic and environmental perspectives, Sarangi said.
Sarangi investigates metalloenzymes like MCR using modern X-ray spectroscopic tools and advanced computer simulations that model the quantum physics underlying chemical reactions.
"While spectroscopy provides an experimental window into specific properties about your system, quantum simulation methods provide additional information about structure, bonding and reactivity properties," she said. "Experiments answer the what and theory answers the why given this specific what."
Her nominators noted the powerful and unusual nature of her combined methodology. Stephen Ragsdale, professor of Biological Chemistry at the University of Michigan, wrote, "Riti's approach is continuing to close the gap between experimental and computational aspects of X-ray spectroscopy. It is also absolutely crucial in understanding the complex biological systems that we and others are studying."
In one recent study, Sarangi and colleagues combined a variety of experimental and theoretical techniques to uncover how enzymes help synthesize methane, revealing a surprising way the enzyme binds to the chemical it converts to methane. Ragsdale called the research "an extraordinary feat."
Supporting users
Sarangi does a lot more than groundbreaking research, spending much of her time supporting the SSRL user community. "Riti is engaged at every level with user support and is someone who is not afraid to get her hands dirty," George wrote.
For example, she developed a computer cluster for implementing various theoretical packages that simulate, interpret or augment experimental X-ray spectroscopy data.
"When I started at SSRL in a user support role, I realized these theoretical tools were rarely leveraged by our biological user community and therefore the full potential of their X-ray datasets was often not realized," said Sarangi. "While I have continued to apply theoretical tools to my own research program, I have also established and made available a high-speed computational cluster to the entire bio-spectroscopy and bio-inspired catalysis user community."
She has also been crucial to keeping SSRL running during the COVID-19 pandemic, her nominators said.
"She played a pivotal role in generating online access programs and coordinating communication and timeline details so users could continue to accomplish our science during the time when SSRL was closed for visitors," Timothy Stemmler, assistance vice president for research and professor of pharmaceutical sciences at Wayne State University, wrote in a letter. "Her efforts to allow online access will surely transform how data is collected at the entire lab moving forward, and will lead to many future discoveries," he wrote.
The nominators also applauded Sarangi's mentoring, training and recruitment of the next generation of scientists. "She has clear skills in organizing and delivering training content and this sets her apart as not just an amazing colleague, but an amazing educator," wrote Stemmler.
Envisioning the future
Looking forward, Sarangi thinks the lessons learned during the pandemic suggest that more researchers could work remotely - something she said accelerated her scientific and operational engagement with staff, users and collaborators. In 20 years, she expects SSRL X-ray science to become an automated and high-throughput experience that integrates multiple complementary X-ray and non-X-ray measurements.
She is also leading efforts to plan the future of structural science at lightsources, based on a series of workshops, whose reports will develop a robust case for investing in X-ray science.
"This is no easy task and has required mastering the details of techniques adjacent to her expertise, diplomacy in bringing diverse ideas in different disciplines together, and hard work," wrote Edward Snell, chief executive officer of the Hauptman-Woodward Medical Research Institute, in a nominating letter.
George also praised Sarangi's leadership and vision. "I have had the distinctive privilege of knowing Farrel quite well, and I am certain that he would approve of this nomination," he wrote. "The SSRL Users' executive committee would be hard pressed to find a better candidate."
The award will be presented to Sarangi at the 2021 SSRL/LCLS Annual Users' Meeting during the plenary session on September 24.
