title: Fourier transform infrared characterization of the azido complex of methane monooxygenase hydroxylase from Methylococcus capsulatus (Bath).
abstract: The azido complex formed in oxidized methane monooxygenase from Methylococcus capsulatus (Bath) was investigated with resonance Raman and FTIR techniques. These experiments show the presence of a nuas(NNN) at approximately 2077 cm-1 which splits to two components at 2059 and 2073 cm-1 with 15N14N2. The vibrational data are assigned to an azido complex bound terminally to one iron(III) at the diiron center. When the azido complex is illuminated at 15 K, a new nuas(NNN) is observed at 2136 cm-1 which is assigned to a photodissociated HN3 within the substrate pocket. We propose a model where an aqua ligand engages a hydrogen bond interaction with the 1N atom of the azido group and acts as at a proton donor during the photolysis process.
authors.affiliation: Department of Environmental & Biomolecular Systems, OGI School of Science & Engineering, Oregon Health & Science University, Beaverton, Oregon 97006-8921, USA.
authors.forename: Shen
authors.initials: S
authors.lastname: Lu
authors.forename: Matthew H
authors.initials: MH
authors.lastname: Sazinsky
authors.forename: James W
authors.initials: JW
authors.lastname: Whittaker
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Lippard
authors.forename: Pierre
authors.initials: P
authors.lastname: Moënne-Loccoz
mesh_terms: D001386:Azides / Q000737:chemistry*; D006860:Hydrogen Bonding; D020619:Methylococcus capsulatus / Q000201:enzymology*; D010105:Oxygenases / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared
chemical_list: D001386:Azides; D010105:Oxygenases; C021555:methane monooxygenase