title: Ligand Rearrangements at Fe/S Cofactors: Slow Isomerization of a Biomimetic [2Fe-2S] Cluster.
abstract: Ligand exchange plays an important role in the biogenesis of Fe/S clusters, most prominently during cluster transfer from a scaffold protein to its target protein. Although in vivo and in vitro studies have provided some insight into this process, the microscopic details of the ligand exchange steps are mostly unknown. In this work, the kinetics of the ligand rearrangement in a biomimetic [2Fe-2S] cluster with mixed S/N capping ligands have been studied. Two geometrical isomers of the cluster are present in solution, and mechanistic insight into the isomerization process was obtained by variable-temperature1H NMR spectroscopy. Combined experimental and computational results reveal that this is an associative process that involves the coordination of a solvent molecule to one of the ferric ions. The cluster isomerizes at least two orders of magnitude faster in its protonated and mixed-valent states. These findings may contribute to a deeper understanding of cluster transfer and sensing processes occurring in Fe/S cluster biogenesis.
authors.affiliation: Universität Göttingen, Institut für Anorganische Chemie, Tammannstrasse 4, 37077, Göttingen, Germany.
authors.forename: Marie
authors.initials: M
authors.lastname: Bergner
authors.affiliation: Max-Planck-Institut für Chemische Energiekonversion, Stiftstrasse 34-36, 45470, Mülheim an der Ruhr, Germany.
authors.forename: Lisa
authors.initials: L
authors.lastname: Roy
authors.affiliation: Universität Göttingen, Institut für Anorganische Chemie, Tammannstrasse 4, 37077, Göttingen, Germany.
authors.forename: Sebastian
authors.initials: S
authors.lastname: Dechert
authors.affiliation: Max-Planck-Institut für Chemische Energiekonversion, Stiftstrasse 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, Stiftstrasse 34-36, 45470, Mülheim an der Ruhr, Germany.
authors.forename: Shengfa
authors.initials: S
authors.lastname: Ye
authors.affiliation: Universität Göttingen, Institut für Anorganische Chemie, Tammannstrasse 4, 37077, Göttingen, Germany.
authors.forename: Franc
authors.identifier: 0000-0002-8613-7862
authors.initials: F
authors.lastname: Meyer
keywords: bioinorganic chemistry; density functional calculations; iron-sulfur clusters; kinetics; ligand rearrangement