Electron and oxygen transfer reactions are integral components of both synthetic and biological chemistry but, in spite of decades of intensive investigation, they remain incompletely understood. The DFG Research Unit on “The Dynamics of Electron Transfer Processes Within Transition-Metal Sites in Biological and Bioinorganic Systems” was set up in 2011 to tackle some of the outstanding questions in the field. “For example, our group has since made significant contributions to understanding the role of the bioinorganic chemistry of copper in the catalytic function of the enzyme tyrosinase,” says Professor Sonja Herres-Pawlis of LMU’s Department of Chemistry. Funding for the Research Unit has now been approved for a further three years, and Herres-Pawlis will serve as joint coordinator for the interuniversity collaboration, together with her colleague Professor Gerald Henkel of the University of Paderborn.
“Our Research Unit makes use of the wide-ranging technical opportunities provided by laser- and synchrotron-based sources of radiation to elucidate the mechanisms of oxygen and electron transfer reactions,” says Herres-Pawlis. In particular, these sources make it possible to measure reaction kinetics on time scales that were previously inaccessible. The researchers are primarily interested in chemical model systems for the study of intramolecular electron transfers performed by a class of proteins that contain copper ions which are essential for their enzymatic functions. Many of the experiments are carried out at the German Electron Synchrotron (DESY) in Hamburg. DESY collaborates closely with the Center for Free-Electron Laser Science (CFEL) in the city, and teams based at the CFEL, led by Professors Michael Rübhausen and Henry Chapman, also form part of the Research Unit.
“The new free-electron lasers make it possible to probe reaction mechanisms on temporal and spatial scales that allow us to capture the dynamics of atomic motions, and this has led to new breakthroughs in the field,” Herres-Pawlis explains. Several of the resulting studies have now been published in highly regarded journals, including Angewandte Chemie. “These studies promise to provide a substantial boost to research in the area of the bioinorganic chemistry of metalloenzymes,” says Herres-Pawlis.
In addition to Professor Sonja Herres-Pawlis and her group at LMU, the Research Unit also includes teams led by Professors Gerald Henkel, Matthias Bauer and Wolf Gero Schmidt, and Dr. Uwe Gerstmann, of the University in Paderborn.