The research described in this newsletter is supported as part of the
Biological Electron Transfer and Catalysis, an Energy Frontier Research Center funded by the
U.S. Department of Energy, Office of Science.
Dynamic Duo: USU Biochemists Identify Tandem Halves of Life-Critical Enzyme
by Mary Ann Muffaletto, Utah State University. Reprinted with permission
Oft-repeated adages praise the virtue and added efficiency of cooperative effort: "Many hands make light work," "Together, we're greater than the sum of our parts" and the like. Utah State University biochemists and colleagues report a tenacious enzyme that uses a similar principle to break nitrogen's unrelenting bonds and convert the life-critical gas into ammonia to fuel the world's food supply.
"Scientists have long assumed the two symmetrical halves of this enzyme, known as 'nitrogenase,' worked independently to produce ammonia," says
Karamatullah Danyal, 2015 USU doctoral graduate, postdoctoral associate at the University of Vermont and lead author on the paper. "Our computer simulations revealed otherwise."
Danyal and faculty mentor
, professor in USU's Department of Chemistry and Biochemistry, USU doctoral student
and USU postdoctoral fellow
, along with Taylor Page, Masaki Horitani, Amy Marts, Dmitriy Lukoyanov and Brian Hoffman of Northwestern University, Dennis Dean of Virginia Tech, Simone Raugei of the Pacific Northwestern National Laboratory and Edwin Antony of Marquette University, published findings in the Oct. 3, 2016, online
Early Edition of the Proceedings of the National Academy of Sciences
"A kinetic model where the two halves of nitrogenase worked independently didn't match new data from our laboratories," says Seefeldt, an American Association for the Advancement of Science Fellow. "When we reconstructed the motion of nitrogenase in a simulation, we found each half worked in tandem to regulate electron movements; an unusual observation in catalysis."
Raugei, a computational chemist at PNNL, likens the enzymatic process to a two-stage engine.
"When one half is pumping out ammonia - the 'exhaust' - the other half is loading the fuel in," he says. "All of this is achieved by complex communication between the two halves."
The team's work is supported by a grant awarded through the U.S. Department of Energy Office of Science's Energy Frontier Research Center program to the Center for Biological and Electron Transfer and Catalysis or "BETCy." Based at Montana State University, BETCy is a seven-institution collaboration, of which USU is a partner.
Seefeldt and his students have long studied how nitrogenases convert nitrogen to ammonia.
"We live in a sea of nitrogen, yet our bodies can't access it from the air," he says. "Instead, we get this life-sustaining compound from protein in our food."
While all living things require nitrogen for survival, the world depends on only two known processes to break nitrogen's ultra-strong bonds and allow conversion. One is a natural, bacterial process and the other is the century-old Haber-Bösch process, which revolutionized fertilizer production and spurred unprecedented growth of the global food supply, but carries a heavy carbon footprint.
"By understanding nitrogenases, we can work toward development of less pollutive, more energy-efficient ammonia production that holds promise not only for food production, but also for development of environmentally cleaner energy," Seefeldt says.
BETCy PI Anne-Frances Miller Chosen New President of the ACS Division of Biological Chemistry
BETCy principal investigator
Anne-Frances Miller was recently chosen to serve as president of the
American Chemical Society-Division of Biological Chemistry (ACS-
DBS). Miller's two-year term began in January 2017.
The ACS-DBC is a 7000-member technical division of the American Chemical Society that administers awards, supports regional meetings and encourages participation of biochemists in the ACS.
By leveraging experience at public as well as private universities, ties with industry and business, and her considerable public engagement, professor Miller aims to represent the diverse membership and interests of the Division of Biological Chemistry, increase biochemists' access to diverse career trajectories, and expand participation and relevance of biological chemistry in decision-making by leadership at the state and national levels.
Miller is a professor of Chemistry at the University of Kentucky and Director of the University of Kentucky NMR spectroscopy facility. Her work as part of the BETCy EFRC engages her directly with basic science underlying energy, a National need. Current members of the Miller Laboratory range from high school students to post-docs, with each member having equal voice and opportunity as evidenced by the time and patience Miller devotes to all members whether bench-side or in the office. Off-campus, Miller can be found engaging the next generation of scientists as coordinator of outreach for the UK Department of Chemistry as well as engaging the members of local and state government as a concerned citizen and professional scientist.
This first year in the position is being framed by Miller as a learning and information-gathering interval, and invites ACS members to contribute their suggestions and recommendations for future activities of the Division of Biological Chemistry. In a recent address to members of the Southeast Enzyme Conference, Miller said, "Our community includes tremendous wisdom and great energy and ambition. We have to be careful about how we allocate our time, so I would like to begin my tenure in this office by hearing from you, my fellow biochemists, about where you think our time and money could have the largest most enduring impact for our community, our country and our planet."
Miller is requesting ACS members to email (
) to initiate a dialog regarding ideas for future activities of the Division of Biological Sciences.
Unique laser-integrated EPR opens new doors for redox center analysis
NREL and BETCy scientists Dave Bobela and David Mulder talk about EPR and light-triggered processes at an open house showcasing the new capabilities. Photo credit: Dennis Schroeder, NREL 40965.
Many enzymes of interest to BETCy rely on specialized redox active centers that function in electron-transfer and catalysis. The properties of these centers often hold the secrets to the mechanisms behind how these enzymes accomplish energy transformation reactions. Electron paramagnetic resonance (EPR) spectroscopy is one valuable tool for probing the electronic and molecular properties of these centers. Recent integration of a broad band, high-power pulsed laser (OpoTek Radiant 355 LD) to an Advanced Spin Resonance Spectrometer located at the National Renewable Energy Laboratory (NREL) has enabled new capability for in-situ controlled and timed optical excitation of EPR samples.
The laser system produces nanosecond pulses of light from 400 to 2100 nm, in variable energy bursts up to 30 mJ/pulse. The pulses are delivered to the EPR system through light tight optical fiber and then coupled into the cavity and sample via enclosed focusing optics.
The system is engineered to be class 1 and uses a series of interlocks to guarantee safe operation. Through synchronization of light and microwave pulses up to 10 Hz repetition rates, the system enables a class of advanced light-induced EPR transient measurements. For BETCy, the unique capability provides new ways through photochemical reactions to capture reaction intermediates and measure in real time how redox active centers function in electron-transfer and energy catalysis.
The Importance of Interdisciplinary Teams
Dan Colman, a postdoctoral researcher in the Boyd lab, is currently a member of the editorial board to the EFRC newsletter, Frontiers in Energy Research
. Below is abridged version of his article entitled The Importance of Interdisciplinary Teams
, which was recently highlighted in the FER
One of the largest and most pressing scientific challenges facing modern societies is closing the gap on future energy demands with clean, abundant, and economical energy sources. At its essence, this challenge is complex and necessitates scientific breakthroughs to develop next-generation energy technology.
To meet this challenge, the U.S. Department of Energy created
Energy Frontier Research Centers
(EFRCs) to answer foundational energy-related scientific problems across diverse energy technology areas, from solar fuels to batteries and beyond. Each EFRC is tasked with overarching goals that are unique and represent areas with exceptional promise for significant energy science advancements.
To meet these goals, EFRCs incorporate diverse, interdisciplinary teams of scientists that can tackle problems from multiple angles. "Funding is one thing, but more important, an EFRC provides a common set of goals for the disparate groups to work towards collaboratively," said
, director of operations and outreach at
Argonne-Northwestern Solar Energy Research
(ANSER), which is developing the fundamental understanding of molecules, materials, and methods necessary to create dramatically more efficient technologies for solar fuels and energy production.
Many great breakthroughs in science have come from individuals or individual laboratories working on specific problems. However, the nature of the problems tasked to EFRCs are too big for one person and demands a community of scientists with diverse expertise. Having interdisciplinary scientific teams allows EFRCs to do more as a center than as individuals or small research groups. "We need all the help we can get to solve complex problems," said
, director of
Photosynthetic Antenna Research Center
Bringing together scientists from diverse fields, institutions, and backgrounds brings challenges in forging collaborations. Scientists from disparate fields and backgrounds often have differing scientific norms and ways of approaching problems. For instance, experimental scientists may list the enormous complexities in a given chemical reaction, whereas modelers and theorists may seek to simplify a problem to make calculations and predictions run on available computing resources.
The development of personal relationships is key to this effort, suggests Blankenship, particularly when EFRCs such as PARC encompass a large geographic range. At PARC, understanding the molecular basis of light-harvesting biological antenna complexes is undertaken to better inform the design of solar energy technologies. Regular "all-hands," in-person meetings have been instrumental in developing personal relationships within PARC. The personal relationships fostered at such meetings help facilitate communication and ongoing collaboration among scientists of differing disciplines.
The scientific world faces the dauntingly large, complex, and imminently pressing problem of meeting future energy demands. This challenge, among others, requires scientific and technological advances that will likely be borne from basic research produced by diverse scientific collaborations. As EFRCs highlight, the way to efficiently meet these solutions lies in the interdisciplinary model of conducting science that has been critical to individual EFRC success.
David Beratan's Laboratory Joins BETCy
We are pleased to announce that
David N. Beratan's Laboratory
has joined the BETCy research team.
Dr. Beratan, R.J. Reynolds Professor of Chemistry at
strengthens BETCy's foundation by applying theoretical approaches to understanding the mechanisms underlying electron bifurcation.
Dr. Beratan attended the September 2016 meeting in Seattle, and has already made significant contributions to the BETCy research program, including representing BETCy at the monthly EFRC Orange Team meeting with his presentation entitled,
The Marcus Inverted Effect & Bifurcated Electron Transfer. This work describes how the Marcus inverted effect likely disables short circuiting between the endergonic and exergonic electron transfer pathways in the bifurcating Nfn protein.
Professor Beratan is affiliated with the Departments of Chemistry, Biochemistry, Physics, as well as Duke's programs in Computational Biology and Bioinformatics, Structural Biology and Biophysics, Nanosciences, and Phononics.
Jacob Artz Represents BETCy on EFRC Early Career Network
, a postdoctoral researcher in the
, has accepted the nomination to represent BETCy in the EFRC Early Career Network
. Dr. Artz, who recently received his doctorate in Chemistry and Biochemistry at
Montana State University,
was nominated to the ECN by the BETCy Progress Review Panel, BETCy's governing body. The charge of the Network is to provide a framework for early career scientists to increase communication across EFRCs as well as providing a mechanism for career networking among young scientists in the EFRCs. The group plans several web meetings every year for EFRC early career scientists, including webinars on writing grant skills, approaches to academic interviews and leveraging collaborative technology.
Dr. Artz's research is currently focused on identifying the structural determinants and mechanisms that account for redox properties of hydrogenases and their relationship to catalytic bias in this class of enzymes.