Simultaneous femtosecond X-ray spectroscopy and diffraction of photosystem II at room temperature

Science. 2013 Apr 26;340(6131):491-5. doi: 10.1126/science.1234273. Epub 2013 Feb 14.

Abstract

Intense femtosecond x-ray pulses produced at the Linac Coherent Light Source (LCLS) were used for simultaneous x-ray diffraction (XRD) and x-ray emission spectroscopy (XES) of microcrystals of photosystem II (PS II) at room temperature. This method probes the overall protein structure and the electronic structure of the Mn4CaO5 cluster in the oxygen-evolving complex of PS II. XRD data are presented from both the dark state (S1) and the first illuminated state (S2) of PS II. Our simultaneous XRD-XES study shows that the PS II crystals are intact during our measurements at the LCLS, not only with respect to the structure of PS II, but also with regard to the electronic structure of the highly radiation-sensitive Mn4CaO5 cluster, opening new directions for future dynamics studies.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Crystallography, X-Ray / methods
  • Cyanobacteria / enzymology
  • Electrons
  • Light
  • Manganese Compounds / chemistry*
  • Oxidation-Reduction
  • Oxides / chemistry*
  • Photosystem II Protein Complex / chemistry*
  • Photosystem II Protein Complex / radiation effects
  • Protein Conformation
  • Spectrometry, X-Ray Emission / methods
  • Temperature
  • Water / chemistry
  • X-Ray Diffraction / methods

Substances

  • Manganese Compounds
  • Oxides
  • Photosystem II Protein Complex
  • Water