title: EPR experiments to elucidate the structure of the ready and unready states of the [NiFe] hydrogenase of Desulfovibrio vulgaris Miyazaki F.
abstract: Isolation and purification of the [NiFe] hydrogenase of Desulfovibrio vulgaris Miyazaki F under aerobic conditions leads to a mixture of two states, Ni-A (unready) and Ni-B (ready). The two states are distinguished by different activation times and different EPR spectra. HYSCORE and ENDOR data and DFT calculations show that both states have an exchangeable proton, albeit with a different (1)H hyperfine coupling. This proton is assigned to the bridging ligand between Ni and Fe. For Ni-B, a hydroxo ligand is found. For Ni-A, either a hydroxo in a different orientation or a hydroperoxo-bridging ligand is present.
authors.affiliation: Max-Planck-Institut für Bioanorganische Chemie, P.O. Box 101365, D-45413 Mülheim an der Ruhr, Germany.
authors.forename: M
authors.initials: M
authors.lastname: van Gastel
authors.forename: C
authors.initials: C
authors.lastname: Fichtner
authors.forename: F
authors.initials: F
authors.lastname: Neese
authors.forename: W
authors.initials: W
authors.lastname: Lubitz
mesh_terms: D016969:Desulfovibrio vulgaris / Q000201:enzymology*; D004578:Electron Spin Resonance Spectroscopy; D006864:Hydrogenase / Q000737:chemistry*; D011487:Protein Conformation; D017550:Spectroscopy, Fourier Transform Infrared
chemical_list: C043296:nickel-iron hydrogenase; D006864:Hydrogenase