@article{LaunDuffusWahlefeldetal.2022,
  author    = {Laun, Konstantin and Duffus, Benjamin R. and Wahlefeld, Stefan and Katz, Sagie and Belger, Dennis Heinz and Hildebrandt, Peter and Mroginski, Maria Andrea and Leimk{\"u}hler, Silke and Zebger, Ingo},
  title     = {Infrared spectroscopy flucidates the inhibitor binding sites in a metal-dependent formate dehydrogenase},
  series = {Chemistry - a European journal},
  journal   = {Chemistry - a European journal},
  publisher = {Wiley-VCH},
  address   = {Weinheim},
  issn      = {0947-6539},
  doi       = {10.1002/chem.202201091},
  pages     = {8},
  year      = {2022},
  abstract  = {Biological carbon dioxide (CO2) reduction is an important step by which organisms form valuable energy-richer molecules required for further metabolic processes. The Mo-dependent formate dehydrogenase (FDH) from Rhodobacter capsulatus catalyzes reversible formate oxidation to CO2 at a bis-molybdopterin guanine dinucleotide (bis-MGD) cofactor. To elucidate potential substrate binding sites relevant for the mechanism, we studied herein the interaction with the inhibitory molecules azide and cyanate, which are isoelectronic to CO2 and charged as formate. We employed infrared (IR) spectroscopy in combination with density functional theory (DFT) and inhibition kinetics. One distinct inhibitory molecule was found to bind to either a non-competitive or a competitive binding site in the secondary coordination sphere of the active site. Site-directed mutagenesis of key amino acid residues in the vicinity of the bis-MGD cofactor revealed changes in both non-competitive and competitive binding, whereby the inhibitor is in case of the latter interaction presumably bound between the cofactor and the adjacent Arg587.},
  language  = {en}
}
@article{LaunDuffusKumaretal.2022,
  author    = {Laun, Konstantin and Duffus, Benjamin R. and Kumar, Hemant and Oudsen, Jean-Pierre H. and Karafoulidi-Retsou, Chara and Waffo, Armel Tadjoung and Hildebrandt, Peter and Ly, Khoa Hoang and Leimk{\"u}hler, Silke and Katz, Sagie and Zebger, Ingo},
  title     = {A minimal light-driven system to study the enzymatic CO2 reduction of formate dehydrogenase},
  series = {ChemCatChem : the European Society Journal for Catalysis},
  volume    = {14},
  journal   = {ChemCatChem : the European Society Journal for Catalysis},
  number    = {24},
  publisher = {Wiley-VCH},
  address   = {Weinheim},
  issn      = {1867-3880},
  doi       = {10.1002/cctc.202201067},
  pages     = {7},
  year      = {2022},
  abstract  = {A minimal light-driven approach was established for studying enzymatic CO2 conversion spectroscopically. The system consists of a photosensitizer Eosin Y, EDTA as a sacrificial electron donor and substrate source, and formate dehydrogenase from Rhodobacter capsulatus (RcFDH) as a biocatalyst. This simplified three-component system provides a photo-triggered control for in situ characterization of the entire catalytic reaction. Direct reduction of RcFDH by the photosensitizer without additional electron carriers was confirmed via UV-Vis spectroscopy, while GC-MS and IR spectroscopy were used to follow photoinduced CO2 generation from EDTA and its subsequent enzymatic reduction, yielding the product formate. Photo-driven and in vitro, dye-based CO2 reduction was inhibited by azide under a mixed (competitive-non-competitive) inhibition mode. IR spectroscopy reveals displacement of the competitively-bound azide by CO2, reflecting an interaction of both with the active site cofactor. This work comprises a proof-of-concept for a new approach to employ light for regulating the reaction of formate dehydrogenases and other CO2 reductases.},
  language  = {en}
}