TY  - JOUR
A1  - Mitzner, Rolf
A1  - Rehanek, Jens
A1  - Kern, Jan
A1  - Gul, Sheraz
A1  - Hattne, Johan
A1  - Taguchi, Taketo
A1  - Alonso-Mori, Roberto
A1  - Tran, Rosalie
A1  - Weniger, Christian
A1  - Schröder, Henning
A1  - Quevedo, Wilson
A1  - Laksmono, Hartawan
A1  - Sierra, Raymond G.
A1  - Han, Guangye
A1  - Lassalle-Kaiser, Benedikt
A1  - Koroidov, Sergey
A1  - Kubicek, Katharina
A1  - Schreck, Simon
A1  - Kunnus, Kristjan
A1  - Brzhezinskaya, Maria
A1  - Firsov, Alexander
A1  - Minitti, Michael P.
A1  - Turner, Joshua J.
A1  - Möller, Stefan
A1  - Sauter, Nicholas K.
A1  - Bogan, Michael J.
A1  - Nordlund, Dennis
A1  - Schlotter, William F.
A1  - Messinger, Johannes
A1  - Borovik, Andrew S.
A1  - Techert, Simone
A1  - de Groot, Frank M. F.
A1  - Föhlisch, Alexander
A1  - Erko, Alexei
A1  - Bergmann, Uwe
A1  - Yachandra, Vittal K.
A1  - Wernet, Philippe
A1  - Yano, Junko
T1  - L-edge x-ray absorption spectroscopy of dilute systems relevant to metalloproteins using an X-ray free-electron laser
JF  - The journal of physical chemistry letters
N2  - L-edge spectroscopy of 3d transition metals provides important electronic structure information and has been used in many fields. However, the use of this method for studying dilute aqueous systems, such as metalloenzymes, has not been prevalent because of severe radiation damage and the lack of suitable detection systems. Here we present spectra from a dilute Mn aqueous solution using a high-transmission zone-plate spectrometer at the Linac Coherent Light Source (LCLS). The spectrometer has been optimized for discriminating the Mn L-edge signal from the overwhelming 0 K-edge background that arises from water and protein itself, and the ultrashort LCLS X-ray pulses can outrun X-ray induced damage. We show that the deviations of the partial-fluorescence yield-detected spectra from the true absorption can be well modeled using the state-dependence of the fluorescence yield, and discuss implications for the application of our concept to biological samples.
Y1  - 2013
U6  - https://doi.org/10.1021/jz401837f
SN  - 1948-7185
VL  - 4
IS  - 21
SP  - 3641
EP  - 3647
PB  - American Chemical Society
CY  - Washington
ER  - 
TY  - JOUR
A1  - Kubin, Markus
A1  - Kern, Jan
A1  - Gul, Sheraz
A1  - Kroll, Thomas
A1  - Chatterjee, Ruchira
A1  - Loechel, Heike
A1  - Fuller, Franklin D.
A1  - Sierra, Raymond G.
A1  - Quevedo, Wilson
A1  - Weniger, Christian
A1  - Rehanek, Jens
A1  - Firsov, Anatoly
A1  - Laksmono, Hartawan
A1  - Weninger, Clemens
A1  - Alonso-Mori, Roberto
A1  - Nordlund, Dennis L.
A1  - Lassalle-Kaiser, Benedikt
A1  - Glownia, James M.
A1  - Krzywinski, Jacek
A1  - Moeller, Stefan
A1  - Turner, Joshua J.
A1  - Minitti, Michael P.
A1  - Dakovski, Georgi L.
A1  - Koroidov, Sergey
A1  - Kawde, Anurag
A1  - Kanady, Jacob S.
A1  - Tsui, Emily Y.
A1  - Suseno, Sandy
A1  - Han, Zhiji
A1  - Hill, Ethan
A1  - Taguchi, Taketo
A1  - Borovik, Andrew S.
A1  - Agapie, Theodor
A1  - Messinger, Johannes
A1  - Erko, Alexei
A1  - Föhlisch, Alexander
A1  - Bergmann, Uwe
A1  - Mitzner, Rolf
A1  - Yachandra, Vittal K.
A1  - Yano, Junko
A1  - Wernet, Philippe
T1  - Soft x-ray absorption spectroscopy of metalloproteins and high-valent metal-complexes at room temperature using free-electron lasers
JF  - Structural dynamics
N2  - 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 similar to 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. (C) 2017 Author(s).
Y1  - 2017
U6  - https://doi.org/10.1063/1.4986627
SN  - 2329-7778
VL  - 4
PB  - American Institute of Physics
CY  - Melville
ER  - 
TY  - JOUR
A1  - Kroll, Thomas
A1  - Kern, Jan
A1  - Kubin, Markus
A1  - Ratner, Daniel
A1  - Gul, Sheraz
A1  - Fuller, Franklin D.
A1  - Löchel, Heike
A1  - Krzywinski, Jacek
A1  - Lutman, Alberto
A1  - Ding, Yuantao
A1  - Dakovski, Georgi L.
A1  - Moeller, Stefan
A1  - Turner, Joshua J.
A1  - Alonso-Mori, Roberto
A1  - Nordlund, Dennis L.
A1  - Rehanek, Jens
A1  - Weniger, Christian
A1  - Firsov, Alexander
A1  - Brzhezinskaya, Maria
A1  - Chatterjee, Ruchira
A1  - Lassalle-Kaiser, Benedikt
A1  - Sierra, Raymond G.
A1  - Laksmono, Hartawan
A1  - Hill, Ethan
A1  - Borovik, Andrew S.
A1  - Erko, Alexei
A1  - Föhlisch, Alexander
A1  - Mitzner, Rolf
A1  - Yachandra, Vittal K.
A1  - Yano, Junko
A1  - Wernet, Philippe
A1  - Bergmann, Uwe
T1  - X-ray absorption spectroscopy using a self-seeded soft X-ray free-electron laser
JF  - Optics express : the international electronic journal of optics
N2  - X-ray free electron lasers (XFELs) enable unprecedented new ways to study the electronic structure and dynamics of transition metal systems. L-edge absorption spectroscopy is a powerful technique for such studies and the feasibility of this method at XFELs for solutions and solids has been demonstrated. However, the required x-ray bandwidth is an order of magnitude narrower than that of self-amplified spontaneous emission (SASE), and additional monochromatization is needed. Here we compare L-edge x-ray absorption spectroscopy (XAS) of a prototypical transition metal system based on monochromatizing the SASE radiation of the linac coherent light source (LCLS) with a new technique based on self-seeding of LCLS. We demonstrate how L-edge XAS can be performed using the self-seeding scheme without the need of an additional beam line monochromator. We show how the spectral shape and pulse energy depend on the undulator setup and how this affects the x-ray spectroscopy measurements. (C) 2016 Optical Society of America
Y1  - 2016
U6  - https://doi.org/10.1364/OE.24.022469
SN  - 1094-4087
VL  - 24
SP  - 22469
EP  - 22480
PB  - Optical Society of America
CY  - Washington
ER  -