title: Molybdenum L-Edge XAS Spectra of MoFe Nitrogenase.
abstract: A molybdenum L-edge X-ray absorption spectroscopy (XAS) study is presented for native and oxidized MoFe protein of nitrogenase as well as Mo-Fe model compounds. Recently collected data on MoFe protein (in oxidized and reduced forms) is compared to previously published Mo XAS data on the isolated FeMo cofactor in NMF solution and put in context of the recent Mo K-edge XAS study, which showed a MoIIIassignment for the molybdenum atom in FeMoco. The L3-edge data are interpreted within a simple ligand-field model, from which a time-dependent density functional theory (TDDFT) approach is proposed as a way to provide further insights into the analysis of the molybdenum L3-edges. The calculated results reproduce well the relative spectral trends that are observed experimentally. Ultimately, these results give further support for the MoIIIassignment in protein-bound FeMoco, as well as isolated FeMoco.
authors.affiliation: Max-Planck-Institut für Chemische Energiekonversion Stiftstr. 34-36, 45470 Mülheim an der Ruhr, Germany ; Present address: Science Institute University of Iceland, Dunhaga 3, 107 Reykjavik, Iceland.
authors.forename: Ragnar
authors.initials: R
authors.lastname: Bjornsson
authors.affiliation: Max-Planck-Institut für Chemische Energiekonversion Stiftstr. 34-36, 45470 Mülheim an der Ruhr, Germany.
authors.forename: Mario U
authors.initials: MU
authors.lastname: Delgado-Jaime
authors.affiliation: Max-Planck-Institut für Chemische Energiekonversion Stiftstr. 34-36, 45470 Mülheim an der Ruhr, Germany ; Present address: Centro Nacional de Pesquisa,em Energia e Materiais, Brazilian Synchrotron Light Laboratory - LNLS, CP 6192 13084-971 Campinas, SP, Brazil.
authors.forename: Frederico A
authors.initials: FA
authors.lastname: Lima
authors.affiliation: Institute for Biochemistry Albert-Ludwigs-Universität Freiburg, Albertstrasse 21, 79104 Freiburg, Germany.
authors.forename: Daniel
authors.initials: D
authors.lastname: Sippel
authors.affiliation: Institute for Biochemistry Albert-Ludwigs-Universität Freiburg, Albertstrasse 21, 79104 Freiburg, Germany.
authors.forename: Julia
authors.initials: J
authors.lastname: Schlesier
authors.affiliation: Max-Planck-Institut für Chemische Energiekonversion Stiftstr. 34-36, 45470 Mülheim an der Ruhr, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Weyhermüller
authors.affiliation: Institute for Biochemistry Albert-Ludwigs-Universität Freiburg, Albertstrasse 21, 79104 Freiburg, Germany.
authors.forename: Oliver
authors.initials: O
authors.lastname: Einsle
authors.affiliation: Max-Planck-Institut für Chemische Energiekonversion Stiftstr. 34-36, 45470 Mülheim an der Ruhr, Germany.
authors.forename: Frank
authors.initials: F
authors.lastname: Neese
authors.affiliation: Max-Planck-Institut für Chemische Energiekonversion Stiftstr. 34-36, 45470 Mülheim an der Ruhr, Germany.
authors.forename: Serena
authors.initials: S
authors.lastname: DeBeer
keywords: FeMoco; L-edges; Molybdenum; Nitrogenase; X-ray spectroscopy