Artificial Hydrogenases Based on Cobaloximes and Heme Oxygenase
International audience 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. T...
Published in: | ChemPlusChem |
---|---|
Main Authors: | , , , , , , , , , |
Other Authors: | , , , , , , , , , , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
HAL CCSD
2016
|
Subjects: | |
Online Access: | https://hal.science/hal-01437557 https://doi.org/10.1002/cplu.201600218 |
Summary: | International audience 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. |
---|