“If one walks around a synchrotron facility, one will invariably see essential equipment developed in the Cramer group,” Aziz said. “For more than three decades, Steve Cramer has played a major role in developing and popularizing synchrotron radiation spectroscopy tools for chemical analysis.”
Aziz and his team are now looking forward to work with Cramer, especially on using and developing further X-ray absorption-, X-ray emission, and RIXS-experiments in the soft X-ray region at the BESSY II synchrotron in Berlin, as well as in the hard X-ray regime at PETRA III at DESY.
Cramer’s current research focuses on similar conundrums as Aziz’s research interests: they want to understand how enzymes in the cells of bacteria fix nitrogen or produce hydrogen, and thus perform processes that are essential for life on Earth. These enzymes contain active iron-sulfur clusters that bind small molecules such as nitrogen, carbon monoxide, and hydrogen. Given the excellent X-ray sources at BESSY II and PETRA III, a natural target for collaborative research will be a better understanding of the electronic structure of the active sites in these enzymes. The long-term goal for such studies is the development of synthetic catalysts that rival the capabilities of natural enzymes.
Stephen P. Cramer is Advanced Light Source Professor at the University of California Davis (UC Davis), Department of Chemistry and does research at the Physical Biosciences Division of the Lawrence Berkeley National Laboratory (LBNL). Since joining UC Davis and LBNL in 1990, Cramer’s group has emphasized development of EXAFS and other synchrotron-based X-ray spectroscopies to study metals in biological systems. The other methods have included soft X-ray absorption, X-ray absorption magnetic circular dichroism (XMCD), high-resolution X-ray fluorescence, resonant inelastic X-ray scattering (RIXS), and most recently, nuclear resonance vibrational spectroscopy (NRVS). Cramer and his team were the first to apply these techniques to metal-containing enzymes. The information from these spectroscopic results provides extra details that are often beyond the reach of X-ray diffraction methods.
Footnote: The Humboldt Research Award is granted in recognition of a researcher’s entire achievements to date. Award winners are invited to spend a period of up to one year cooperating on a long-term research project with specialist colleagues at a research institution in Germany. The stay may be divided up into blocks. The Humboldt Foundation grants up to 100 Humboldt Research Awards annually. Nominations may be submitted by established academics in Germany. The award is valued at 60,000 euros.