Room temperature X-ray absorption spectroscopy of metalloenzymes with drop-on-demand sample delivery at XFELs

Isabel Bogacz; Hiroki Makita; Philipp S Simon; Miao Zhang; Margaret D Doyle; Ruchira Chatterjee; Thomas Fransson; Clemens Weninger; Franklin Fuller; Leland Gee; Takahiro Sato; Matthew Seaberg; Roberto Alonso-Mori; Uwe Bergmann; Vittal K Yachandra; Jan Kern; Junko Yano

doi:10.1515/pac-2023-0213

Room temperature X-ray absorption spectroscopy of metalloenzymes with drop-on-demand sample delivery at XFELs

Pure Appl Chem. 2023 Apr 19;95(8):891-897. doi: 10.1515/pac-2023-0213. eCollection 2023 Aug.

Authors

Isabel Bogacz¹, Hiroki Makita¹, Philipp S Simon¹, Miao Zhang¹, Margaret D Doyle¹, Ruchira Chatterjee¹, Thomas Fransson², Clemens Weninger³, Franklin Fuller⁴, Leland Gee⁴, Takahiro Sato⁴, Matthew Seaberg⁴, Roberto Alonso-Mori⁴, Uwe Bergmann⁵, Vittal K Yachandra¹, Jan Kern¹, Junko Yano¹

Affiliations

¹ Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, 94720, Berkeley, CA, USA.
² Department of Theoretical chemistry and Biology, KTH Royal Institute of Technology, Stockholm, Sweden.
³ MAX IV Laboratory, Lund University, Lund, Sweden.
⁴ LCLS, SLAC National Accelerator Laboratory, 94025, Menlo Park, CA, USA.
⁵ Department of Physics, University of Wisconsin-Madison, 53706, Madison, WI, USA.

Abstract

X-ray crystallography and X-ray spectroscopy using X-ray free electron lasers plays an important role in understanding the interplay of structural changes in the protein and the chemical changes at the metal active site of metalloenzymes through their catalytic cycles. As a part of such an effort, we report here our recent development of methods for X-ray absorption spectroscopy (XAS) at XFELs to study dilute biological samples, available in limited volumes. Our prime target is Photosystem II (PS II), a multi subunit membrane protein complex, that catalyzes the light-driven water oxidation reaction at the Mn₄CaO₅ cluster. This is an ideal system to investigate how to control multi-electron/proton chemistry, using the flexibility of metal redox states, in coordination with the protein and the water network. We describe the method that we have developed to collect XAS data using PS II samples with a Mn concentration of <1 mM, using a drop-on-demand sample delivery method.

Keywords: Manganese; PhotoIUPAC 2022; X-ray absorption spectroscopy; X-ray free electron lasers; photosystem II; water oxidation.

Abstract

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