Soft x-ray absorption spectroscopy of metalloproteins and high-valent metal-complexes at room temperature using free-electron lasers
نویسندگان
چکیده
X-ray absorption spectroscopy at the L-edge of 3d transition metals provides unique information on the local metal charge and spin states by directly probing 3d-derived molecular orbitals through 2p-3d transitions. However, this soft x-ray technique has been rarely used at synchrotron facilities for mechanistic studies of metalloenzymes due to the difficulties of x-ray-induced sample damage and strong background signals from light elements that can dominate the low metal signal. Here, we combine femtosecond soft x-ray pulses from a free-electron laser with a novel x-ray fluorescence-yield spectrometer to overcome these difficulties. We present L-edge absorption spectra of inorganic high-valent Mn complexes (Mn ∼ 6-15 mmol/l) with no visible effects of radiation damage. We also present the first L-edge absorption spectra of the oxygen evolving complex (Mn4CaO5) in Photosystem II (Mn < 1 mmol/l) at room temperature, measured under similar conditions. Our approach opens new ways to study metalloenzymes under functional conditions.
منابع مشابه
Energy-dispersive X-ray emission spectroscopy using an X-ray free-electron laser in a shot-by-shot mode.
The ultrabright femtosecond X-ray pulses provided by X-ray free-electron lasers open capabilities for studying the structure and dynamics of a wide variety of systems beyond what is possible with synchrotron sources. Recently, this "probe-before-destroy" approach has been demonstrated for atomic structure determination by serial X-ray diffraction of microcrystals. There has been the question wh...
متن کاملX-ray Absorption Spectroscopy and Coherent X- ray Diffraction Imaging for Time-Resolved Investigation of the Biological Complexes: Computer Modelling towards the XFEL Experiment
The development of the next generation synchrotron radiation sources – free electron lasers – is approaching to become an effective tool for the time-resolved experiments aimed to solve actual problems in various fields such as chemistry, biology, medicine, etc. In order to demonstrate, how these experiments may be performed for the real systems to obtain information at the atomic and macromole...
متن کاملSynthesis, Characterization and Investigation of Magnetic Properties of Co3O4/CoFe2O4 Nanocomposite Prepared by Calcination of [CO(SALEN)(PPH3)(H2O)]4[Fe(CN)6] and [Co(Salophen)(PPH3)(H2O)]4[Fe(CN)6] Binary Complex Salts
In this research the synthesis of [Co(Salen)(PPh3)(H2O)]4[Fe(CN)6] and [Co(Salophen)(PPh3)(H2O)]4[Fe(CN)6] schiff base complexes was reported. Co3O4/CoFe2O4 magnetic nanoparticles were prepared by calcination of these complexes at 500, 550 and 600°C. Precursor complexes were identified by FT-IR and UV-Vis spectroscopy and their thermal behavior was studied via TG/DTA. Nanomagnetic samples were ...
متن کاملNear Edge X-ray Absorption Fine Structure Spectroscopy with X-Ray Free-Electron Lasers
We demonstrate the feasibility of Near Edge X-ray Absorption Fine Structure (NEXAFS) spectroscopy on solids by means of femtosecond soft x-ray pulses from a free-electron laser (FEL). Our experiments, carried out at the Free-Electron Laser at Hamburg (FLASH), used a special sample geometry, spectrographic energy dispersion, single shot position-sensitive detection and a data normalization proce...
متن کاملThe effect of increasing of iron concentration on the physical properties of zinc-iron ferrite nanoparticles
In this research, zinc-iron ferrite nanoparticles were synthesized by thermal treatment method. The presence of crystalline phases by X-ray diffraction (XRD) was determined by X-ray diffraction (XRD), which confirmed the presence of crystalline phases in all nanoparticles. The particle size and morphology of the nanoparticles were obtained using Field Emission Scanning Electron Microscopy (FESE...
متن کامل