@article{ZengLeimkuehlerWollenbergeretal.2017,
  author    = {Zeng, Ting and Leimk{\"u}hler, Silke and Wollenberger, Ulla and Fourmond, Vincent},
  title     = {Transient Catalytic Voltammetry of Sulfite Oxidase Reveals Rate Limiting Conformational Changes},
  series = {Journal of the American Chemical Society},
  volume    = {139},
  journal   = {Journal of the American Chemical Society},
  publisher = {American Chemical Society},
  address   = {Washington},
  issn      = {0002-7863},
  doi       = {10.1021/jacs.7b05480},
  pages     = {11559 -- 11567},
  year      = {2017},
  abstract  = {Sulfite oxidases are metalloenzymes that oxidize sulfite to sulfate at a molybdenum active site. In vertebrate sulfite oxidases, the electrons generated at the Mo center are transferred to an external electron acceptor via a heme domain, which can adopt two conformations: a "closed" conformation, suitable for internal electron transfer, and an "open" conformation suitable for intermolecular electron transfer. This conformational change is an integral part of the catalytic cycle. Sulfite oxidases have been wired to electrode surfaces, but their immobilization leads to a significant decrease in their catalytic activity, raising the question of the occurrence of the conformational change when the enzyme is on an electrode. We recorded and quantitatively modeled for the first time the transient response of the catalytic cycle of human sulfite oxidase immobilized on an electrode. We show that conformational changes still occur on the electrode, but at a lower rate than in solution, which is the reason for the decrease in activity of sulfite oxidases upon immobilization.},
  language  = {en}
}
@article{StrippDuffusFourmondetal.2022,
  author    = {Stripp, Sven T. and Duffus, Benjamin R. and Fourmond, Vincent and Leger, Christophe and Leimk{\"u}hler, Silke and Hirota, Shun and Hu, Yilin and Jasniewski, Andrew and Ogata, Hideaki and Ribbe, Markus W.},
  title     = {Second and outer coordination sphere effects in nitrogenase, hydrogenase, formate dehydrogenase, and CO dehydrogenase},
  series = {Chemical reviews : CR},
  volume    = {122},
  journal   = {Chemical reviews : CR},
  number    = {14},
  publisher = {American Chemical Society},
  address   = {Washington, DC},
  issn      = {0009-2665},
  doi       = {10.1021/acs.chemrev.1c00914},
  pages     = {11900 -- 11973},
  year      = {2022},
  abstract  = {Gases like H-2, N-2, CO2, and CO are increasingly recognized as critical feedstock in "green" energy conversion and as sources of nitrogen and carbon for the agricultural and chemical sectors. However, the industrial transformation of N-2, CO2, and CO and the production of H-2 require significant energy input, which renders processes like steam reforming and the Haber-Bosch reaction economically and environmentally unviable. Nature, on the other hand, performs similar tasks efficiently at ambient temperature and pressure, exploiting gas-processing metalloenzymes (GPMs) that bind low-valent metal cofactors based on iron, nickel, molybdenum, tungsten, and sulfur. Such systems are studied to understand the biocatalytic principles of gas conversion including N-2 fixation by nitrogenase and H-2 production by hydrogenase as well as CO2 and CO conversion by formate dehydrogenase, carbon monoxide dehydrogenase, and nitrogenase. In this review, we emphasize the importance of the cofactor/protein interface, discussing how second and outer coordination sphere effects determine, modulate, and optimize the catalytic activity of GPMs. These may comprise ionic interactions in the second coordination sphere that shape the electron density distribution across the cofactor, hydrogen bonding changes, and allosteric effects. In the outer coordination sphere, proton transfer and electron transfer are discussed, alongside the role of hydrophobic substrate channels and protein structural changes. Combining the information gained from structural biology, enzyme kinetics, and various spectroscopic techniques, we aim toward a comprehensive understanding of catalysis beyond the first coordination sphere.},
  language  = {en}
}