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Effects of x-ray free-electron laser pulse intensity on the Mn K β 1,3x-ray emission spectrum in photosystem II - A case study for metalloprotein crystals and solutions

Fransson, Thomas ; Alonso-Mori, Roberto ; Chatterjee, Ruchira ; Cheah, Mun Hon ; Ibrahim, Mohamed ; Hussein, Rana ; Zhang, Miao ; Fuller, Franklin ; Gul, Sheraz and Kim, In Sik , et al. (2021) In Structural Dynamics 8(6).
Abstract

In the last ten years, x-ray free-electron lasers (XFELs) have been successfully employed to characterize metalloproteins at room temperature using various techniques including x-ray diffraction, scattering, and spectroscopy. The approach has been to outrun the radiation damage by using femtosecond (fs) x-ray pulses. An example of an important and damage sensitive active metal center is the Mn4CaO5 cluster in photosystem II (PS II), the catalytic site of photosynthetic water oxidation. The combination of serial femtosecond x-ray crystallography and Kβ x-ray emission spectroscopy (XES) has proven to be a powerful multimodal approach for simultaneously probing the overall protein structure and the electronic state of the Mn4CaO5 cluster... (More)

In the last ten years, x-ray free-electron lasers (XFELs) have been successfully employed to characterize metalloproteins at room temperature using various techniques including x-ray diffraction, scattering, and spectroscopy. The approach has been to outrun the radiation damage by using femtosecond (fs) x-ray pulses. An example of an important and damage sensitive active metal center is the Mn4CaO5 cluster in photosystem II (PS II), the catalytic site of photosynthetic water oxidation. The combination of serial femtosecond x-ray crystallography and Kβ x-ray emission spectroscopy (XES) has proven to be a powerful multimodal approach for simultaneously probing the overall protein structure and the electronic state of the Mn4CaO5 cluster throughout the catalytic (Kok) cycle. As the observed spectral changes in the Mn4CaO5 cluster are very subtle, it is critical to consider the potential effects of the intense XFEL pulses on the Kβ XES signal. We report here a systematic study of the effects of XFEL peak power, beam focus, and dose on the Mn Kβ1,3 XES spectra in PS II over a wide range of pulse parameters collected over seven different experimental runs using both microcrystal and solution PS II samples. Our findings show that for beam intensities ranging from ∼5 × 1015 to 5 × 1017 W/cm2 at a pulse length of ∼35 fs, the spectral effects are small compared to those observed between S-states in the Kok cycle. Our results provide a benchmark for other XFEL-based XES studies on metalloproteins, confirming the viability of this approach.

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organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Structural Dynamics
volume
8
issue
6
article number
064302
publisher
American Institute of Physics (AIP)
external identifiers
  • scopus:85120068938
  • pmid:34849380
ISSN
2329-7778
DOI
10.1063/4.0000130
language
English
LU publication?
yes
additional info
Publisher Copyright: © 2021 Author(s).
id
a5416ce3-bd02-4b87-a78f-df4ceeaad078
date added to LUP
2022-01-24 08:40:34
date last changed
2024-06-16 00:17:49
@article{a5416ce3-bd02-4b87-a78f-df4ceeaad078,
  abstract     = {{<p>In the last ten years, x-ray free-electron lasers (XFELs) have been successfully employed to characterize metalloproteins at room temperature using various techniques including x-ray diffraction, scattering, and spectroscopy. The approach has been to outrun the radiation damage by using femtosecond (fs) x-ray pulses. An example of an important and damage sensitive active metal center is the Mn4CaO5 cluster in photosystem II (PS II), the catalytic site of photosynthetic water oxidation. The combination of serial femtosecond x-ray crystallography and Kβ x-ray emission spectroscopy (XES) has proven to be a powerful multimodal approach for simultaneously probing the overall protein structure and the electronic state of the Mn4CaO5 cluster throughout the catalytic (Kok) cycle. As the observed spectral changes in the Mn4CaO5 cluster are very subtle, it is critical to consider the potential effects of the intense XFEL pulses on the Kβ XES signal. We report here a systematic study of the effects of XFEL peak power, beam focus, and dose on the Mn Kβ1,3 XES spectra in PS II over a wide range of pulse parameters collected over seven different experimental runs using both microcrystal and solution PS II samples. Our findings show that for beam intensities ranging from ∼5 × 1015 to 5 × 1017 W/cm2 at a pulse length of ∼35 fs, the spectral effects are small compared to those observed between S-states in the Kok cycle. Our results provide a benchmark for other XFEL-based XES studies on metalloproteins, confirming the viability of this approach.</p>}},
  author       = {{Fransson, Thomas and Alonso-Mori, Roberto and Chatterjee, Ruchira and Cheah, Mun Hon and Ibrahim, Mohamed and Hussein, Rana and Zhang, Miao and Fuller, Franklin and Gul, Sheraz and Kim, In Sik and Simon, Philipp S. and Bogacz, Isabel and Makita, Hiroki and De Lichtenberg, Casper and Song, Sanghoon and Batyuk, Alexander and Sokaras, Dimosthenis and Massad, Ramzi and Doyle, Margaret and Britz, Alexander and Weninger, Clemens and Zouni, Athina and Messinger, Johannes and Yachandra, Vittal K. and Yano, Junko and Kern, Jan and Bergmann, Uwe}},
  issn         = {{2329-7778}},
  language     = {{eng}},
  month        = {{11}},
  number       = {{6}},
  publisher    = {{American Institute of Physics (AIP)}},
  series       = {{Structural Dynamics}},
  title        = {{Effects of x-ray free-electron laser pulse intensity on the Mn K β <sub>1,3</sub>x-ray emission spectrum in photosystem II - A case study for metalloprotein crystals and solutions}},
  url          = {{http://dx.doi.org/10.1063/4.0000130}},
  doi          = {{10.1063/4.0000130}},
  volume       = {{8}},
  year         = {{2021}},
}