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Title: Artificial hydrogenases based on cobaloximes and heme oxygenase

The insertion of cobaloxime catalysts in the heme-binding pocket of heme oxygenase (HO) yields artificial hydrogenases active for H 2 evolution in neutral aqueous solutions. These novel biohybrids have been purified and characterized by using UV/visible and EPR spectroscopy. These analyses revealed the presence of two distinct binding conformations, thereby providing the cobaloxime with hydrophobic and hydrophilic environments, respectively. Quantum chemical/molecular mechanical docking calculations found open and closed conformations of the binding pocket owing to mobile amino acid residues. HO-based biohybrids incorporating a {Co(dmgH) 2} (dmgH 2 = dimethylglyoxime) catalytic center displayed up to threefold increased turnover numbers with respect to the cobaloxime alone or to analogous sperm whale myoglobin adducts. Here, this study thus provides a strong basis for further improvement of such biohybrids, using well-designed modifications of the second and outer coordination spheres, through site-directed mutagenesis of the host protein.
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  1. Univ. Grenoble Alpes, Grenoble Cedex (France)
  2. Argonne National Lab. (ANL), Lemont, IL (United States)
  3. Tohoku Univ., Sendai (Japan)
  4. Univ. Grenoble Alpes, Grenoble Cedex (France); Univ. Pierre et Marie Curie, Paris (France)
Publication Date:
Grant/Contract Number:
AC02-06CH11357; AC02-6CH11357; 2412006; 24350081; 23550186; 25109504; 15K05555; 15H00912
Accepted Manuscript
Journal Name:
Additional Journal Information:
Journal Volume: 81; Journal Issue: 10; Journal ID: ISSN 2192-6506
ChemPubSoc Europe
Research Org:
Argonne National Lab. (ANL), Argonne, IL (United States)
Sponsoring Org:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
Country of Publication:
United States
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; biohybrid species; hydrogen evolution; artificial enzymes; bioinspired chemistry; cobalt; heme proteins; enzyme models; biohybrids
OSTI Identifier:
Alternate Identifier(s):
OSTI ID: 1401439