XFEL: New technique reveals insights on Vitamin B12

Researchers have implemented a new technique, based on the European XFEL’s ultrashort pulses, to gain insights into two compounds featuring vitamin B12. B12 is an important compound in many biological systems, and the new method will allow scientists to develop a much deeper understanding of its structure and behavior. The technique will enable better insights for a host of biological molecules, and could help in designing targeted drug therapies.

Scientists used the European XFEL’s bright and ultrashort X-ray pulses to probe the evolution of two B12 compounds in time, at intervals of just 10 trillionths of a second (100 fs). Scientists used green light to illuminate the B12 compounds, and looked at them using a new method of X-ray spectroscopy called time-resolved Valence-to-Core X-ray Emission Spectroscopy (tr-VtC XES) to take snapshots of each molecule focusing on different aspects of their structure. Through the combination of optical and X-ray measurements, researchers were able to learn about the specific behaviors of these B12 compounds, such as their reactions to visible light, as well as the way the molecules vibrate and recover their initial configuration.

“Similar techniques have been used to investigate B12 using only visible and ultraviolet light,” says Frederico Lima, Instrument Scientist at the FXE instrument. “But the advantage of using tr-VtC XES is that you can get an element sensitive measurement that is also rather straightforward to predict using modern quantum chemical theory. In other words, it becomes easier to understand what each individual element in the molecule is doing. This gives us a more precise picture of the vitamin’s behavior than previously possible.”

The study, published in the Journal of the American Chemical Society, also addresses a problem with measuring tr-VtC XES on biological systems such as those containing B12, namely, that they produce small, difficult to detect signals.

“The high-rate of X-ray flashes produced by the European XFEL allows us to compensate for very tiny signals, such as those produced by low concentration biological samples,” says Roseanne Sension, lead author on the study. “This is the first implementation of measuring such a small signal, but opens the door for other biological systems in the future.”

The scientists stress that the method will allow a better understanding of these biologically important molecules and others, and will provide a route to understanding vital biological processes such as the interactions of vitamin compounds with therapeutic drugs. This could one day enable applications in targeted drug delivery, or light-activated drug control.

For more information:

Watching Excited State Dynamics with Optical and X-ray Probes: The Excited State Dynamics of Aquocobalamin and Hydroxocobalamin

Roseanne J. Sension, Taylor P. McClain, Ryan M. Lamb, Roberto Alonso-Mori, Frederico Alves Lima, Fernando Ardana-Lamas, Mykola Biednov, Matthieu Chollet, Taewon Chung, Aniruddha Deb, Paul A. Dewan Jr., Leland B. Gee, Joel Huang Ze En, Yifeng Jiang, Dmitry Khakhulin, Jianhao Li, Lindsay B. Michocki, Nicholas A. Miller, Florian Otte, Yohei Uemura, Tim B. van Driel, and James E. Penner-Hahn

Journal of the American Chemical Society Article ASAP

DOI: 10.1021/jacs.3c04099

Contacts:

Science contact:

Dr Frederico Lima
Tel: +49-40-8998-4610
E-mail: frederico.lima@xfel.eu

Press contact:

Dr Bernd Ebeling
Tel: +49-40-8998-6921
E-mail: bernd.ebeling@xfel.eu