Artificial Hydrogenases Based on Cobaloximes and Heme Oxygenase
Abstract 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...
Published in: | ChemPlusChem |
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Main Authors: | , , , , , , , , , |
Other Authors: | , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Wiley
2016
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Subjects: | |
Online Access: | http://dx.doi.org/10.1002/cplu.201600218 https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1002%2Fcplu.201600218 https://onlinelibrary.wiley.com/doi/pdf/10.1002/cplu.201600218 https://onlinelibrary.wiley.com/doi/full-xml/10.1002/cplu.201600218 https://chemistry-europe.onlinelibrary.wiley.com/doi/am-pdf/10.1002/cplu.201600218 |
Summary: | Abstract 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. 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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