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  • 1.
    Chatterjee, Ruchira
    et al.
    Lawrence Berkeley Natl Lab, Mol Biophys & Integrated Bioimaging Div, Berkeley, CA 94720 USA.
    Lassalle, Louise
    Lawrence Berkeley Natl Lab, Mol Biophys & Integrated Bioimaging Div, Berkeley, CA 94720 USA.
    Gul, Sheraz
    Lawrence Berkeley Natl Lab, Mol Biophys & Integrated Bioimaging Div, Berkeley, CA 94720 USA.
    Fuller, Franklin D.
    Lawrence Berkeley Natl Lab, Mol Biophys & Integrated Bioimaging Div, Berkeley, CA 94720 USA.
    Young, Iris D.
    Lawrence Berkeley Natl Lab, Mol Biophys & Integrated Bioimaging Div, Berkeley, CA 94720 USA.
    Ibrahim, Mohamed
    Humboldt Univ, Inst Biol, D-10099 Berlin, Germany.
    de Lichtenberg, Casper
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för kemi - Ångström, Molekylär biomimetik. Umea Univ, Inst Kemi, Kemiskt Biol Centrum, S-90187 Umea, Sweden.
    Cheah, Mun Hon
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för kemi - Ångström, Molekylär biomimetik.
    Zouni, Athina
    Humboldt Univ, Inst Biol, D-10099 Berlin, Germany.
    Messinger, Johannes
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för kemi - Ångström, Molekylär biomimetik. Umea Univ, Inst Kemi, Kemiskt Biol Centrum, S-90187 Umea, Sweden.
    Yachandra, Vittal K.
    Lawrence Berkeley Natl Lab, Mol Biophys & Integrated Bioimaging Div, Berkeley, CA 94720 USA.
    Kern, Jan
    Lawrence Berkeley Natl Lab, Mol Biophys & Integrated Bioimaging Div, Berkeley, CA 94720 USA.
    Yano, Junko
    Lawrence Berkeley Natl Lab, Mol Biophys & Integrated Bioimaging Div, Berkeley, CA 94720 USA.
    Structural isomers of the S-2 state in photosystem II: do they exist at room temperature and are they important for function?2019Inngår i: Physiologia Plantarum: An International Journal for Plant Biology, ISSN 0031-9317, E-ISSN 1399-3054, Vol. 166, nr 1, s. 60-72Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    In nature, an oxo-bridged Mn4CaO5 cluster embedded in photosystem II (PSII), a membrane-bound multi-subunit pigment protein complex, catalyzes the water oxidation reaction that is driven by light-induced charge separations in the reaction center of PSII. The Mn4CaO5 cluster accumulates four oxidizing equivalents to enable the four-electron four-proton catalysis of two water molecules to one dioxygen molecule and cycles through five intermediate S-states, S-0-S-4 in the Kok cycle. One important question related to the catalytic mechanism of the oxygen-evolving complex (OEC) that remains is, whether structural isomers are present in some of the intermediate S-states and if such equilibria are essential for the mechanism of the O-O bond formation. Here we compare results from electron paramagnetic resonance (EPR) and X-ray absorption spectroscopy (XAS) obtained at cryogenic temperatures for the S-2 state of PSII with structural data collected of the S-1, S-2 and S-3 states by serial crystallography at neutral pH (approximate to 6.5) using an X-ray free electron laser at room temperature. While the cryogenic data show the presence of at least two structural forms of the S-2 state, the room temperature crystallography data can be well-described by just one S-2 structure. We discuss the deviating results and outline experimental strategies for clarifying this mechanistically important question.

  • 2.
    Chatterjee, Ruchira
    et al.
    Lawrence Berkeley Natl Lab, Mol Biophys & Integrated Bioimaging Div, 1 Cyclotron Rd, Berkeley, CA 94704 USA.
    Weninger, Clemens
    SLAC Natl Accelerator Lab, LCLS, Menlo Pk, CA 94025 USA.
    Loukianov, Anton
    SLAC Natl Accelerator Lab, LCLS, Menlo Pk, CA 94025 USA.
    Gul, Sheraz
    Lawrence Berkeley Natl Lab, Mol Biophys & Integrated Bioimaging Div, 1 Cyclotron Rd, Berkeley, CA 94704 USA.
    Fuller, Franklin D.
    Lawrence Berkeley Natl Lab, Mol Biophys & Integrated Bioimaging Div, 1 Cyclotron Rd, Berkeley, CA 94704 USA;SLAC Natl Accelerator Lab, LCLS, Menlo Pk, CA 94025 USA.
    Cheah, Mun Hon
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för kemi - Ångström, Molekylär biomimetik.
    Fransson, Thomas
    SLAC Natl Accelerator Lab, Stanford PULSE Inst, Menlo Pk, CA 94025 USA.
    Pham, Cindy C.
    Lawrence Berkeley Natl Lab, Mol Biophys & Integrated Bioimaging Div, 1 Cyclotron Rd, Berkeley, CA 94704 USA.
    Nelson, Silke
    SLAC Natl Accelerator Lab, LCLS, Menlo Pk, CA 94025 USA.
    Song, Sanghoon
    SLAC Natl Accelerator Lab, LCLS, Menlo Pk, CA 94025 USA.
    Britz, Alexander
    SLAC Natl Accelerator Lab, LCLS, Menlo Pk, CA 94025 USA.
    Messinger, Johannes
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för kemi - Ångström, Molekylär biomimetik. Umea Univ, Kemiskt Biol Ctr, Inst Kemi, SE-90187 Umea, Sweden.
    Bergmann, Uwe
    SLAC Natl Accelerator Lab, Stanford PULSE Inst, Menlo Pk, CA 94025 USA.
    Alonso-Mori, Roberto
    SLAC Natl Accelerator Lab, LCLS, Menlo Pk, CA 94025 USA.
    Yachandra, Vittal K.
    Lawrence Berkeley Natl Lab, Mol Biophys & Integrated Bioimaging Div, 1 Cyclotron Rd, Berkeley, CA 94704 USA.
    Kern, Jan
    Lawrence Berkeley Natl Lab, Mol Biophys & Integrated Bioimaging Div, 1 Cyclotron Rd, Berkeley, CA 94704 USA.
    Yano, Junko
    Lawrence Berkeley Natl Lab, Mol Biophys & Integrated Bioimaging Div, 1 Cyclotron Rd, Berkeley, CA 94704 USA.
    XANES and EXAFS of dilute solutions of transition metals at XFELs2019Inngår i: Journal of Synchrotron Radiation, ISSN 0909-0495, E-ISSN 1600-5775, Vol. 26, s. 1716-1724Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    This work has demonstrated that X-ray absorption spectroscopy (XAS), both Mn XANES and EXAFS, of solutions with millimolar concentrations of metal is possible using the femtosecond X-ray pulses from XFELs. Mn XAS data were collected using two different sample delivery methods, a Rayleigh jet and a drop-on-demand setup, with varying concentrations of Mn. Here, a new method for normalization of XAS spectra based on solvent scattering that is compatible with data collection from a highly variable pulsed source is described. The measured XANES and EXAFS spectra of such dilute solution samples are in good agreement with data collected at synchrotron sources using traditional scanning protocols. The procedures described here will enable XFEL-based XAS on dilute biological samples, especially metalloproteins, with low sample consumption. Details of the experimental setup and data analysis methods used in this XANES and EXAFS study are presented. This method will also benefit XAS performed at high-repetition-rate XFELs such as the European XFEL, LCLS-II and LCLS-II-HE.

  • 3.
    Christianson, Helena C.
    et al.
    Lund Univ, Dept Clin Sci, Sect Oncol & Pathol, Lund, Sweden..
    Menard, Julien A.
    Lund Univ, Dept Clin Sci, Sect Oncol & Pathol, Lund, Sweden..
    Chandran, Vineesh Indira
    Lund Univ, Dept Clin Sci, Sect Oncol & Pathol, Lund, Sweden..
    Bourseau-Guilmain, Erika
    Montpellier Univ, CNRS, UMR 5237, CRBM, Montpellier, France..
    Shevela, Dmitry
    Umea Univ, Chem Biol Ctr, Dept Chem, Umea, Sweden..
    Lidfeldt, Jon
    Lund Univ, Dept Clin Sci, Sect Oncol & Pathol, Lund, Sweden..
    Mansson, Ann-Sofie
    Lund Univ, Dept Clin Sci, Sect Oncol & Pathol, Lund, Sweden..
    Pastorekova, Silvia
    Slovak Acad Sci, Inst Virol, Biomed Res Ctr, Bratislava, Slovakia..
    Messinger, Johannes
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för kemi - Ångström, Molekylär biomimetik. Umea Univ, Chem Biol Ctr, Dept Chem, Umea, Sweden.
    Belting, Mattias
    Lund Univ, Dept Clin Sci, Sect Oncol & Pathol, Lund, Sweden.;Skane Univ Hosp, Dept Oncol, Lund, Sweden..
    Tumor antigen glycosaminoglycan modification regulates antibody-drug conjugate delivery and cytotoxicity2017Inngår i: OncoTarget, ISSN 1949-2553, E-ISSN 1949-2553, Vol. 8, nr 40, s. 66960-66974Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Aggressive cancers are characterized by hypoxia, which is a key driver of tumor development and treatment resistance. Proteins specifically expressed in the hypoxic tumor microenvironment thus represent interesting candidates for targeted drug delivery strategies. Carbonic anhydrase (CAIX) has been identified as an attractive treatment target as it is highly hypoxia specific and expressed at the cell-surface to promote cancer cell aggressiveness. Here, we find that cancer cell internalization of CAIX is negatively regulated by post-translational modification with chondroitin or heparan sulfate glycosaminoglycan chains. We show that perturbed glycosaminoglycan modification results in increased CAIX endocytosis. We hypothesized that perturbation of CAIX glycosaminoglycan conjugation may provide opportunities for enhanced drug delivery to hypoxic tumor cells. In support of this concept, pharmacological inhibition of glycosaminoglycan biosynthesis with xylosides significantly potentiated the internalization and cytotoxic activity of an antibody-drug conjugate (ADC) targeted at CAIX. Moreover, cells expressing glycosaminoglycan-deficient CAIX were significantly more sensitive to ADC treatment as compared with cells expressing wild-type CAIX. We find that inhibition of CAIX endocytosis is associated with an increased localization of glycosaminoglycan-conjugated CAIX in membrane lipid raft domains stabilized by caveolin-1 clusters. The association of CAIX with caveolin-1 was partially attenuated by acidosis, i.e. another important feature of malignant tumors. Accordingly, we found increased internalization of CAIX at acidic conditions. These findings provide first evidence that intracellular drug delivery at pathophysiological conditions of malignant tumors can be attenuated by tumor antigen glycosaminoglycan modification, which is of conceptual importance in the future development of targeted cancer treatments.

  • 4.
    Chrysina, Maria
    et al.
    Max Planck Inst Chem Energiekonvers, D-45470 Mulheim, Germany.
    Heyno, Eiri
    Ruhr Univ Bochum, Fac Biol & Biotechnol, Plant Biochem, D-44780 Bochum, Germany.
    Kutin, Yury
    Max Planck Inst Chem Energiekonvers, D-45470 Mulheim, Germany;TU Dortmund Univ, Dept Chem & Chem Biol, D-44227 Dortmund, Germany.
    Reus, Michael
    Max Planck Inst Chem Energiekonvers, D-45470 Mulheim, Germany.
    Nilsson, Håkan
    Umea Univ, Chem Biol Ctr, Dept Chem, S-90187 Umea, Sweden.
    Nowaczyk, Marc M.
    Ruhr Univ Bochum, Fac Biol & Biotechnol, Plant Biochem, D-44780 Bochum, Germany.
    DeBeer, Serena
    Max Planck Inst Chem Energiekonvers, D-45470 Mulheim, Germany.
    Neese, Frank
    Max Planck Inst Kohlenforsch, D-45470 Mulheim, Germany.
    Messinger, Johannes
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för kemi - Ångström, Molekylär biomimetik. Umea Univ, Chem Biol Ctr, Dept Chem, S-90187 Umea, Sweden.
    Lubitz, Wolfgang
    Max Planck Inst Chem Energiekonvers, D-45470 Mulheim, Germany.
    Cox, Nicholas
    Australian Natl Univ, Res Sch Chem, Canberra, ACT 2601, Australia.
    Five-coordinate Mn-IV intermediate in the activation of nature's water splitting cofactor2019Inngår i: Proceedings of the National Academy of Sciences of the United States of America, ISSN 0027-8424, E-ISSN 1091-6490, Vol. 116, nr 34, s. 16841-16846Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Nature's water splitting cofactor passes through a series of catalytic intermediates (S-0-S-4) before O-O bond formation and O-2 release. In the second last transition (S-2 to S-3) cofactor oxidation is coupled to water molecule binding to Mn1. It is this activated, water-enriched all Mn-IV form of the cofactor that goes on to form the O-O bond, after the next light-induced oxidation to S-4. How cofactor activation proceeds remains an open question. Here, we report a so far not described intermediate (S-3') in which cofactor oxidation has occurred without water insertion. This intermediate can be trapped in a significant fraction of centers (> 50%) in (i) chemical-modified cofactors in which Ca2+ is exchanged with Sr2+; the Mn4O5Sr cofactor remains active, but the S-2-S-3 and S-3-S-0 transitions are slower than for the Mn4O5Ca cofactor; and (ii) upon addition of 3% vol/vol methanol; methanol is thought to act as a substrate water analog. The S-3' electron paramagnetic resonance (EPR) signal is significantly broader than the untreated S-3 signal (2.5 T vs. 1.5 T), indicating the cofactor still contains a 5-coordinate Mn ion, as seen in the preceding S-2 state. Magnetic double resonance data extend these findings revealing the electronic connectivity of the S-3' cofactor is similar to the high spin form of the preceding S-2 state, which contains a cuboidal Mn3O4Ca unit tethered to an external, 5-coordinate Mn ion (Mn-4). These results demonstrate that cofactor oxidation regulates water molecule insertion via binding to Mn-4. The interaction of ammonia with the cofactor is also discussed.

  • 5.
    Conlan, Brendon l
    et al.
    Australian Natl Univ, Res Sch Biol Sci, Acton, ACT 0200, Australia.
    Govindjee, Govindjee
    Department of Plant Biology, Department of Biochemistry, Center of Biophysics & Quantitative Biology, University of Illinois at Urbana-Champaign Urbana, USA.
    Messinger, Johannes
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för kemi - Ångström, Molekylär biomimetik. Umea Univ, Dept Chem, Linnaeus Vag 6, S-90187 Umea, Sweden.
    Thomas John Wydrzynski (8 July 1947-16 March 2018): Obituary in Photosynthesis Research, June 2019, Volume 140, Issue 3, pp 253–2612019Annet (Annet vitenskapelig)
    Abstract [en]

    With this Tribute, we remember and honor Thomas John (Tom) Wydrzynski. Tom was a highly innovative, independent and committed researcher, who had, early in his career, defined his life-long research goal. He was committed to understand how Photosystem II produces molecular oxygen from water, using the energy of sunlight, and to apply this knowledge towards making artificial systems. In this tribute, we summarize his research journey, which involved working on soft money' in several laboratories around the world for many years, as well as his research achievements. We also reflect upon his approach to life, science and student supervision, as we perceive it. Tom was not only a thoughtful scientist that inspired many to enter this field of research, but also a wonderful supervisor and friend, who is deeply missed (see footnote*).

  • 6.
    Fuller, Franklin D.
    et al.
    Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA..
    Gul, Sheraz
    Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA..
    Chatterjee, Ruchira
    Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA..
    Burgie, E. Sethe
    Washington Univ St Louis, Dept Biol, St Louis, MO USA..
    Young, Iris D.
    Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA..
    Lebrette, Hugo
    Stockholm Univ, Dept Biochem & Biophys, Stockholm, Sweden..
    Srinivas, Vivek
    Stockholm Univ, Dept Biochem & Biophys, Stockholm, Sweden..
    Brewster, Aaron S.
    Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA..
    Michels-Clark, Tara
    Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA..
    Clinger, Jonathan A.
    Rice Univ, Dept BioSci, Houston, TX USA..
    Andi, Babak
    Natl Synchrotron Light Source II, Brookhaven Natl Lab, Upton, NY USA..
    Ibrahim, Mohamed
    Humboldt Univ, Inst Biol, Berlin, Germany..
    Pastor, Ernest
    Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA..
    de Lichtenberg, Casper
    Hussein, Rana
    Humboldt Univ, Inst Biol, Berlin, Germany..
    Pollock, Christopher J.
    Penn State Univ, Dept Chem, University Pk, PA USA..
    Zhang, Miao
    Humboldt Univ, Inst Biol, Berlin, Germany..
    Stan, Claudiu A.
    Stanford PULSE Inst, SLAC Natl Accelerator Lab, Menlo Pk, CA USA..
    Kroll, Thomas
    SSRL, SLAC Natl Accelerator Lab, Menlo Pk, CA USA..
    Fransson, Thomas
    Stanford PULSE Inst, SLAC Natl Accelerator Lab, Menlo Pk, CA USA..
    Weninger, Clemens
    Stanford PULSE Inst, SLAC Natl Accelerator Lab, Menlo Pk, CA USA.;LCLS, SLAC Natl Accelerator Lab, Menlo Pk, CA USA..
    Kubin, Markus
    Helmholtz Zentrum Berlin Mat & Energie GmbH, Inst Methods & Instrumentat Synchrotron Radiat Re, Berlin, Germany..
    Aller, Pierre
    Diamond Light Source Ltd, Harwell Sci & Innovat Campus, Didcot, Oxon, England..
    Lassalle, Louise
    Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA..
    Braeuer, Philipp
    Diamond Light Source Ltd, Harwell Sci & Innovat Campus, Didcot, Oxon, England.;Univ Oxford, Dept Biochem, Oxford, England..
    Miller, Mitchell D.
    Rice Univ, Dept BioSci, Houston, TX USA..
    Amin, Muhamed
    Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA.;Zewail City Sci & Technol, Ctr Photon & Smart Mat, Giza, Egypt..
    Koroidov, Sergey
    Umea Univ, Kemiskt Biol Ctr, Inst Kemi, Umea, Sweden.;Stanford PULSE Inst, SLAC Natl Accelerator Lab, Menlo Pk, CA USA..
    Roessler, Christian G.
    Natl Synchrotron Light Source II, Brookhaven Natl Lab, Upton, NY USA.;Ventana Med Syst Inc, Tucson, AZ USA..
    Allaire, Marc
    Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA..
    Sierra, Raymond G.
    LCLS, SLAC Natl Accelerator Lab, Menlo Pk, CA USA..
    Docker, Peter T.
    Diamond Light Source Ltd, Harwell Sci & Innovat Campus, Didcot, Oxon, England..
    Glownia, James M.
    LCLS, SLAC Natl Accelerator Lab, Menlo Pk, CA USA..
    Nelson, Silke
    LCLS, SLAC Natl Accelerator Lab, Menlo Pk, CA USA..
    Koglin, Jason E.
    LCLS, SLAC Natl Accelerator Lab, Menlo Pk, CA USA..
    Zhu, Diling
    LCLS, SLAC Natl Accelerator Lab, Menlo Pk, CA USA..
    Chollet, Matthieu
    LCLS, SLAC Natl Accelerator Lab, Menlo Pk, CA USA..
    Song, Sanghoon
    LCLS, SLAC Natl Accelerator Lab, Menlo Pk, CA USA..
    Lemke, Henrik
    LCLS, SLAC Natl Accelerator Lab, Menlo Pk, CA USA.;Paul Scherrer Inst, SwissFEL, Villigen, Switzerland..
    Liang, Mengning
    LCLS, SLAC Natl Accelerator Lab, Menlo Pk, CA USA..
    Sokaras, Dimosthenis
    SSRL, SLAC Natl Accelerator Lab, Menlo Pk, CA USA..
    Alonso-Mori, Roberto
    LCLS, SLAC Natl Accelerator Lab, Menlo Pk, CA USA..
    Zouni, Athina
    Humboldt Univ, Inst Biol, Berlin, Germany..
    Messinger, Johannes
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för kemi - Ångström, Molekylär biomimetik. Umea Univ, Kemiskt Biol Ctr, Inst Kemi, Umea, Sweden..
    Bergmann, Uwe
    Stanford PULSE Inst, SLAC Natl Accelerator Lab, Menlo Pk, CA USA..
    Boal, Amie K.
    Penn State Univ, Dept Chem, University Pk, PA USA.;Penn State Univ, Dept Biochem & Mol Biol, University Pk, PA USA..
    Bollinger, J. Martin, Jr.
    Penn State Univ, Dept Chem, University Pk, PA USA.;Penn State Univ, Dept Biochem & Mol Biol, University Pk, PA USA..
    Krebs, Carsten
    Penn State Univ, Dept Chem, University Pk, PA USA.;Penn State Univ, Dept Biochem & Mol Biol, University Pk, PA USA..
    Hoegbom, Martin
    Stanford Univ, Dept Chem, Stanford, CA USA..
    Phillips, George N., Jr.
    Rice Univ, Dept BioSci, Houston, TX USA.;Rice Univ, Dept Chem, Houston, TX USA..
    Vierstra, Richard D.
    Washington Univ St Louis, Dept Biol, St Louis, MO USA..
    Sauter, Nicholas K.
    Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA..
    Orville, Allen M.
    Diamond Light Source Ltd, Harwell Sci & Innovat Campus, Didcot, Oxon, England..
    Kern, Jan
    Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA.;LCLS, SLAC Natl Accelerator Lab, Menlo Pk, CA USA..
    Yachandra, Vittal K.
    Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA..
    Yano, Junko
    Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA..
    Drop-on-demand sample delivery for studying biocatalysts in action at X-ray free-electron lasers2017Inngår i: Nature Methods, ISSN 1548-7091, E-ISSN 1548-7105, Vol. 14, nr 4, s. 443-+Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    X-ray crystallography at X-ray free-electron laser sources is a powerful method for studying macromolecules at biologically relevant temperatures. Moreover, when combined with complementary techniques like X-ray emission spectroscopy, both global structures and chemical properties of metalloenzymes can be obtained concurrently, providing insights into the interplay between the protein structure and dynamics and the chemistry at an active site. The implementation of such a multimodal approach can be compromised by conflicting requirements to optimize each individual method. In particular, the method used for sample delivery greatly affects the data quality. We present here a robust way of delivering controlled sample amounts on demand using acoustic droplet ejection coupled with a conveyor belt drive that is optimized for crystallography and spectroscopy measurements of photochemical and chemical reactions over a wide range of time scales. Studies with photosystem IIII, the phytochrome photoreceptor, and ribonucleotide reductase R2 illustrate the power and versatility of this method.

  • 7. Govindjee,
    et al.
    Messinger, Johannes
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för kemi - Ångström, Molekylär biomimetik.
    We remember those who left us in the recent past2019Inngår i: Physiologia Plantarum: An International Journal for Plant Biology, ISSN 0031-9317, E-ISSN 1399-3054, Vol. 166, nr 1, s. 7-11Artikkel i tidsskrift (Annet vitenskapelig)
  • 8.
    Kawde, Anurag
    et al.
    Umeå University, Department of Chemistry, Sweden; European Synchrotron Radiation Facility (ESRF), Grenoble, France.
    Annamalai, Alagappan
    Umea University, Department of Physics, Sweden.
    Amidani, Lucia
    European Synchrotron Radiation Facility (ESRF), Grenoble, France.
    Boniolo, Manuel
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för kemi - Ångström, Molekylär biomimetik.
    Kwong, Wai Ling
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för kemi - Ångström, Molekylär biomimetik.
    Sellstedt, Anita
    Umeå University, Department of Plant Physiology, Umeå Plant Science Centre (UPSC), Umeå, Sweden.
    Glatzel, Pieter
    European Synchrotron Radiation Facility (ESRF), Grenoble, France.
    Wågberg, Thomas
    Umea University, Department of Physics, Sweden.
    Messinger, Johannes
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för kemi - Ångström, Molekylär biomimetik. Umeå University, Department of Chemistry, Sweden.
    Photo-electrochemical hydrogen production from neutral phosphate buffer and seawater using micro-structured p-Si photo-electrodes functionalized by solution-based methods2018Inngår i: Sustainable Energy & Fuels, E-ISSN 2398-4902, Vol. 2, nr 10, s. 2215-2223Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Solar fuels such as H2 generated from sunlight and seawater using earth-abundant materials are expected to be a crucial component of a next generation renewable energy mix. We herein report a systematic analysis of the photo-electrochemical performance of TiO2 coated, microstructured p-Si photoelectrodes (p-Si/TiO2) that were functionalized with CoOx and NiOx for H2 generation. These photocathodes were synthesized from commercial p-Si wafers employing wet chemical methods. In neutral phosphate buffer and standard 1 sun illumination, the p-Si/TiO2/NiOx photoelectrode showed a photocurrent density of 1.48 mA cm2 at zero bias (0 VRHE), which was three times and 15 times better than the photocurrent densities of p-Si/TiO2/CoOx and p-Si/TiO2, respectively. No decline in activity was observed over a five hour test period, yielding a Faradaic efficiency of 96% for H2 production. Based on the electrochemical characterizations and the high energy resolution fluorescence detected X-ray absorption near edge structure (HERFD-XANES) and emission spectroscopy measurements performed at the Ti Ka1 fluorescence line, the superior performance of the p-Si/TiO2/ NiOx photoelectrode was attributed to improved charge transfer properties induced by the NiOx coating on the protective TiO2 layer, in combination with a higher catalytic activity of NiOx for H2-evolution. Moreover, we report here an excellent photo-electrochemical performance of p-Si/TiO2/NiOx photoelectrode in corrosive artificial seawater (pH 8.4) with an unprecedented photocurrent density of 10 mA cm2 at an applied potential of 0.7 VRHE, and of 20 mA cm2 at 0.9 VRHE. The applied bias photon-to-current conversion efficiency (ABPE) at 0.7 VRHE and 10 mA cm2 was found to be 5.1%.

  • 9.
    Kawde, Anurag
    et al.
    Umea Univ, Dept Chem, Umea, Sweden;ESRF, Grenoble, France.
    Annamalai, Alagappan
    Umea Univ, Dept Phys, Umea, Sweden.
    Sellstedt, Anita
    Umea Univ, Dept Plant Physiol, UPSC, Umea, Sweden.
    Glatzel, Pieter
    ESRF, Grenoble, France.
    Wagberg, Thomas
    Umea Univ, Dept Phys, Umea, Sweden.
    Messinger, Johannes
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för kemi - Ångström, Molekylär biomimetik. Umea Univ, Dept Chem, Umea, Sweden.
    A microstructured p-Si photocathode outcompetes Pt as a counter electrode to hematite in photoelectrochemical water splitting2019Inngår i: Dalton Transactions, ISSN 1477-9226, E-ISSN 1477-9234, Vol. 48, nr 4, s. 1166-1170Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Herein, we communicate about an Earth-abundant semiconductor photocathode (p-Si/TiO2/NiOx) as an alternative for the rare and expensive Pt as a counter electrode for overall photoelectrochemical water splitting. The proposed photoelectrochemical (PEC) water-splitting device mimics the Z-scheme observed in natural photosynthesis by combining two photoelectrodes in a parallel-illumination mode. A nearly 60% increase in the photocurrent density (J(ph)) for pristine -Fe2O3 and a 77% increase in the applied bias photocurrent efficiency (ABPE) were achieved by replacing the conventionally used Pt cathode with an efficient, cost effective p-Si/TiO2/NiOx photocathode under parallel illumination. The resulting photocurrent density of 1.26 mA cm(-2) at 1.23V(RHE) represents a new record performance for hydrothermally grown pristine -Fe2O3 nanorod photoanodes in combination with a photocathode, which opens the prospect for further improvement by doping -Fe2O3 or by its decoration with co-catalysts. Electrochemical impedance spectroscopy measurements suggest that this significant performance increase is due to the enhancement of the space-charge field in -Fe2O3.

  • 10.
    Kern, Jan
    et al.
    Lawrence Berkeley Natl Lab, Mol Biophys & Integrated Bioimaging Div, Berkeley, CA 94720 USA.
    Chatterjee, Ruchira
    Lawrence Berkeley Natl Lab, Mol Biophys & Integrated Bioimaging Div, Berkeley, CA 94720 USA.
    Young, Iris D.
    Lawrence Berkeley Natl Lab, Mol Biophys & Integrated Bioimaging Div, Berkeley, CA 94720 USA.
    Fuller, Franklin D.
    Lawrence Berkeley Natl Lab, Mol Biophys & Integrated Bioimaging Div, Berkeley, CA 94720 USA.
    Lassalle, Louise
    Lawrence Berkeley Natl Lab, Mol Biophys & Integrated Bioimaging Div, Berkeley, CA 94720 USA.
    Ibrahim, Mohamed
    Humboldt Univ, Inst Biol, Berlin, Germany.
    Gul, Sheraz
    Lawrence Berkeley Natl Lab, Mol Biophys & Integrated Bioimaging Div, Berkeley, CA 94720 USA.
    Fransson, Thomas
    SLAC Natl Accelerator Lab, Stanford PULSE Inst, Menlo Pk, CA USA;Heidelberg Univ, Interdisciplinary Ctr Sci Comp, Heidelberg, Germany.
    Brewster, Aaron S.
    Lawrence Berkeley Natl Lab, Mol Biophys & Integrated Bioimaging Div, Berkeley, CA 94720 USA.
    Alonso-Mori, Roberto
    SLAC Natl Accelerator Lab, LCLS, Menlo Pk, CA USA.
    Hussein, Rana
    Humboldt Univ, Inst Biol, Berlin, Germany.
    Zhang, Miao
    Humboldt Univ, Inst Biol, Berlin, Germany.
    Douthit, Lacey
    Lawrence Berkeley Natl Lab, Mol Biophys & Integrated Bioimaging Div, Berkeley, CA 94720 USA.
    de Lichtenberg, Casper
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för kemi - Ångström, Molekylär biomimetik. Umeå Univ, Kemiskt Biol Ctr, Inst Kemi, Umeå, Sweden.
    Cheah, Mun Hon
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för kemi - Ångström, Molekylär biomimetik.
    Shevela, Dmitry
    Umea Univ, Kemiskt Biol Ctr, Inst Kemi, Umea, Sweden.
    Wersig, Julia
    Humboldt Univ, Inst Biol, Berlin, Germany.
    Seuffert, Ina
    Humboldt Univ, Inst Biol, Berlin, Germany.
    Sokaras, Dimosthenis
    SLAC Natl Accelerator Lab, SSRL, Menlo Pk, CA USA.
    Pastor, Ernest
    Lawrence Berkeley Natl Lab, Mol Biophys & Integrated Bioimaging Div, Berkeley, CA 94720 USA.
    Weninger, Clemens
    SLAC Natl Accelerator Lab, LCLS, Menlo Pk, CA USA.
    Kroll, Thomas
    SLAC Natl Accelerator Lab, SSRL, Menlo Pk, CA USA.
    Sierra, Raymond G.
    SLAC Natl Accelerator Lab, LCLS, Menlo Pk, CA USA.
    Aller, Pierre
    Diamond Light Source Ltd, Harwell Sci & Innovat Campus, Didcot, Oxon, England.
    Butryn, Agata
    Diamond Light Source Ltd, Harwell Sci & Innovat Campus, Didcot, Oxon, England.
    Orville, Allen M.
    Diamond Light Source Ltd, Harwell Sci & Innovat Campus, Didcot, Oxon, England.
    Liang, Mengning
    SLAC Natl Accelerator Lab, LCLS, Menlo Pk, CA USA.
    Batyuk, Alexander
    SLAC Natl Accelerator Lab, LCLS, Menlo Pk, CA USA.
    Koglin, Jason E.
    SLAC Natl Accelerator Lab, LCLS, Menlo Pk, CA USA.
    Carbajo, Sergio
    SLAC Natl Accelerator Lab, LCLS, Menlo Pk, CA USA.
    Boutet, Sebastien
    SLAC Natl Accelerator Lab, LCLS, Menlo Pk, CA USA.
    Moriarty, Nigel W.
    Lawrence Berkeley Natl Lab, Mol Biophys & Integrated Bioimaging Div, Berkeley, CA 94720 USA.
    Holton, James M.
    Lawrence Berkeley Natl Lab, Mol Biophys & Integrated Bioimaging Div, Berkeley, CA 94720 USA;SLAC Natl Accelerator Lab, SSRL, Menlo Pk, CA USA;Univ Calif San Francisco, Dept Biochem & Biophys, San Francisco, CA 94143 USA.
    Dobbek, Holger
    Humboldt Univ, Inst Biol, Berlin, Germany.
    Adams, Paul D.
    Lawrence Berkeley Natl Lab, Mol Biophys & Integrated Bioimaging Div, Berkeley, CA 94720 USA;Univ Calif Berkeley, Dept Bioengn, Berkeley, CA 94720 USA.
    Bergmann, Uwe
    SLAC Natl Accelerator Lab, Stanford PULSE Inst, Menlo Pk, CA USA.
    Sauter, Nicholas K.
    Lawrence Berkeley Natl Lab, Mol Biophys & Integrated Bioimaging Div, Berkeley, CA 94720 USA.
    Zouni, Athina
    Humboldt Univ, Inst Biol, Berlin, Germany.
    Messinger, Johannes
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för kemi - Ångström, Molekylär biomimetik. Umeå Univ, Kemiskt Biol Ctr, Inst Kemi, Umeå, Sweden.
    Yano, Junko
    Lawrence Berkeley Natl Lab, Mol Biophys & Integrated Bioimaging Div, Berkeley, CA 94720 USA.
    Yachandra, Vittal K.
    Lawrence Berkeley Natl Lab, Mol Biophys & Integrated Bioimaging Div, Berkeley, CA 94720 USA.
    Structures of the intermediates of Kok's photosynthetic water oxidation clock2018Inngår i: Nature, ISSN 0028-0836, E-ISSN 1476-4687, Vol. 563, nr 7731, s. 421-425Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Inspired by the period-four oscillation in flash-induced oxygen evolution of photo system II discovered by Joliot in 1969, Kok performed additional experiments and proposed a five-state kinetic model for photosynthetic oxygen evolution, known as Kok's S-state clock or cycle(1,2). The model comprises four (meta)stable intermediates (S-0, S-1, S-2 and S-3) and one transient S-4 state, which precedes dioxygen formation occurring in a concerted reaction from two water-derived oxygens bound at an oxo-bridged tetra manganese calcium (Mn4CaO5) cluster in the oxygen-evolving complex(3-7). This reaction is coupled to the two-step reduction and protonation of the mobile plastoquinone Q(B) at the acceptor side of PSII. Here, using serial femto second X-ray crystallography and simultaneous X-ray emission spectroscopy with multi-flash visible laser excitation at room temperature, we visualize all (meta) stable states of Kok's cycle as high-resolution structures (2.04-2.08 angstrom). In addition, we report structures of two transient states at 150 and 400 mu s, revealing notable structural changes including the binding of one additional 'water', Ox, during the S-2 -> S-3 state transition. Our results suggest that one water ligand to calcium (W3) is directly involved in substrate delivery. The binding of the additional oxygen Ox in the S-3 state between Ca and Mnl supports O-O bond formation mechanisms involving O5 as one substrate, where Ox is either the other substrate oxygen or is perfectly positioned to refill the O5 position during O-2 release. Thus, our results exclude peroxo-bond formation in the S-3 state, and the nucleophilic attack of W3 onto W2 is unlikely.

  • 11.
    Krieger-Liszkay, Anja
    et al.
    Univ Paris Saclay, Univ Paris Sud, Inst Integrat Biol Cell, CEA Saclay,CNRS, F-91191 Gif Sur Yvette, France.
    Spetea, Cornelia
    Univ Gothenburg, Dept Biol & Environm Sci, Gothenburg, Sweden.
    Messinger, Johannes
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för kemi - Ångström, Molekylär biomimetik. Umea Univ, Dept Chem, Umea, Sweden.
    Photosynthesis: European Congress on Photosynthesis Research2019Inngår i: Physiologia Plantarum: An International Journal for Plant Biology, ISSN 0031-9317, E-ISSN 1399-3054, Vol. 166, nr 1, s. 4-6Artikkel i tidsskrift (Annet vitenskapelig)
  • 12.
    Kubin, Markus
    et al.
    Helmholtz Zentrum Berlin Mat & Energie GmbH, Inst Methods & Instrumentat Synchrotron Radiat Re, D-12489 Berlin, Germany..
    Kern, Jan
    Lawrence Berkeley Natl Lab, Mol Biophys & Integrated Bioimaging Div, Berkeley, CA 94720 USA.;SLAC Natl Accelerator Lab, Linac Coherent Light Source, Menlo Pk, CA 94025 USA..
    Gul, Sheraz
    Lawrence Berkeley Natl Lab, Mol Biophys & Integrated Bioimaging Div, Berkeley, CA 94720 USA..
    Kroll, Thomas
    SLAC Natl Accelerator Lab, Stanford Synchrotron Radiat Lightsource, Menlo Pk, CA 94025 USA..
    Chatterjee, Ruchira
    Lawrence Berkeley Natl Lab, Mol Biophys & Integrated Bioimaging Div, Berkeley, CA 94720 USA..
    Loechel, Heike
    Helmholtz Zentrum Berlin Mat & Energie GmbH, Inst Nanometre Opt & Technol, D-12489 Berlin, Germany..
    Fuller, Franklin D.
    Lawrence Berkeley Natl Lab, Mol Biophys & Integrated Bioimaging Div, Berkeley, CA 94720 USA..
    Sierra, Raymond G.
    SLAC Natl Accelerator Lab, Linac Coherent Light Source, Menlo Pk, CA 94025 USA..
    Quevedo, Wilson
    Helmholtz Zentrum Berlin Mat & Energie GmbH, Inst Methods & Instrumentat Synchrotron Radiat Re, D-12489 Berlin, Germany..
    Weniger, Christian
    Helmholtz Zentrum Berlin Mat & Energie GmbH, Inst Methods & Instrumentat Synchrotron Radiat Re, D-12489 Berlin, Germany..
    Rehanek, Jens
    Helmholtz Zentrum Berlin Mat & Energie GmbH, Inst Nanometre Opt & Technol, D-12489 Berlin, Germany.;Paul Scherrer Inst, CH-5232 Villigen, Switzerland..
    Firsov, Anatoly
    Helmholtz Zentrum Berlin Mat & Energie GmbH, Inst Nanometre Opt & Technol, D-12489 Berlin, Germany..
    Laksmono, Hartawan
    SLAC Natl Accelerator Lab, Stanford PULSE Inst, Menlo Pk, CA 94025 USA..
    Weninger, Clemens
    SLAC Natl Accelerator Lab, Linac Coherent Light Source, Menlo Pk, CA 94025 USA.;SLAC Natl Accelerator Lab, Stanford PULSE Inst, Menlo Pk, CA 94025 USA..
    Alonso-Mori, Roberto
    SLAC Natl Accelerator Lab, Linac Coherent Light Source, Menlo Pk, CA 94025 USA..
    Nordlund, Dennis L.
    Lassalle-Kaiser, Benedikt
    Synchrotron SOLEIL, F-91191 Gif Sur Yvette, France..
    Glownia, James M.
    SLAC Natl Accelerator Lab, Linac Coherent Light Source, Menlo Pk, CA 94025 USA..
    Krzywinski, Jacek
    SLAC Natl Accelerator Lab, Linac Coherent Light Source, Menlo Pk, CA 94025 USA..
    Moeller, Stefan
    SLAC Natl Accelerator Lab, Linac Coherent Light Source, Menlo Pk, CA 94025 USA..
    Turner, Joshua J.
    SLAC Natl Accelerator Lab, Linac Coherent Light Source, Menlo Pk, CA 94025 USA..
    Minitti, Michael P.
    SLAC Natl Accelerator Lab, Linac Coherent Light Source, Menlo Pk, CA 94025 USA..
    Dakovski, Georgi L.
    SLAC Natl Accelerator Lab, Linac Coherent Light Source, Menlo Pk, CA 94025 USA..
    Koroidov, Sergey
    SLAC Natl Accelerator Lab, Stanford PULSE Inst, Menlo Pk, CA 94025 USA.;Umea Univ, Inst Kemi, Kem Biol Ctr, SE-90187 Umea, Sweden..
    Kawde, Anurag
    Umea Univ, Inst Kemi, Kem Biol Ctr, SE-90187 Umea, Sweden..
    Kanady, Jacob S.
    CALTECH, Div Chem & Chem Engn, Pasadena, CA 91125 USA..
    Tsui, Emily Y.
    CALTECH, Div Chem & Chem Engn, Pasadena, CA 91125 USA..
    Suseno, Sandy
    CALTECH, Div Chem & Chem Engn, Pasadena, CA 91125 USA..
    Han, Zhiji
    CALTECH, Div Chem & Chem Engn, Pasadena, CA 91125 USA..
    Hill, Ethan
    Univ Calif Irvine, Dept Chem, 1102 Nat Sci 2, Irvine, CA 92697 USA..
    Taguchi, Taketo
    Univ Calif Irvine, Dept Chem, 1102 Nat Sci 2, Irvine, CA 92697 USA..
    Borovik, Andrew S.
    Univ Calif Irvine, Dept Chem, 1102 Nat Sci 2, Irvine, CA 92697 USA..
    Agapie, Theodor
    CALTECH, Div Chem & Chem Engn, Pasadena, CA 91125 USA..
    Messinger, Johannes
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för kemi - Ångström, Molekylär biomimetik. Umea Univ, Inst Kemi, Kem Biol Ctr, SE-90187 Umea, Sweden.;Uppsala Univ, Angstrom Lab, Mol Biomimet, Dept Chem, SE-75237 Uppsala, Sweden..
    Erko, Alexei
    Helmholtz Zentrum Berlin Mat & Energie GmbH, Inst Nanometre Opt & Technol, D-12489 Berlin, Germany..
    Foehlisch, Alexander
    Helmholtz Zentrum Berlin Mat & Energie GmbH, Inst Methods & Instrumentat Synchrotron Radiat Re, D-12489 Berlin, Germany.;Univ Potsdam, Inst Phys & Astron, D-14476 Potsdam, Germany..
    Bergmann, Uwe
    SLAC Natl Accelerator Lab, Stanford PULSE Inst, Menlo Pk, CA 94025 USA..
    Mitzner, Rolf
    Helmholtz Zentrum Berlin Mat & Energie GmbH, Inst Methods & Instrumentat Synchrotron Radiat Re, D-12489 Berlin, Germany..
    Yachandra, Vittal K.
    Lawrence Berkeley Natl Lab, Mol Biophys & Integrated Bioimaging Div, Berkeley, CA 94720 USA..
    Yano, Junko
    Lawrence Berkeley Natl Lab, Mol Biophys & Integrated Bioimaging Div, Berkeley, CA 94720 USA..
    Wernet, Philippe
    Helmholtz Zentrum Berlin Mat & Energie GmbH, Inst Methods & Instrumentat Synchrotron Radiat Re, D-12489 Berlin, Germany..
    Soft x-ray absorption spectroscopy of metalloproteins and high-valent metal-complexes at room temperature using free-electron lasers2017Inngår i: STRUCTURAL DYNAMICS, ISSN 2329-7778, Vol. 4, nr 5, artikkel-id 054307Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    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).

  • 13.
    Kwong, Wai Ling
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för kemi - Ångström, Molekylär biomimetik. Umeå University, Umeå, Sweden.
    Gracia-Espino, Eduardo
    Umeå University, Umeå, Sweden.
    Lee, Cheng Choo
    Umeå University, Umeå, Sweden.
    Sandström, Robin
    Umeå University, Umeå, Sweden.
    Wågberg, Thomas
    Umeå University, Umeå, Sweden.
    Messinger, Johannes
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för kemi - Ångström, Molekylär biomimetik. Umeå University, Umeå, Sweden.
    Cationic Vacancy Defects in Iron Phosphide: A Promising Route toward Efficient and Stable Hydrogen Evolution by Electrochemical Water Splitting2017Inngår i: ChemSusChem, ISSN 1864-5631, E-ISSN 1864-564X, Vol. 10, nr 22, s. 4544-4551Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Engineering the electronic properties of transition metal phosphides has shown great effectiveness in improving their intrinsic catalytic activity for the hydrogen evolution reaction (HER) in water splitting applications. Herein, we report for the first time, the creation of Fe vacancies as an approach to modulate the electronic structure of iron phosphide (FeP). The Fe vacancies were produced by chemical leaching of Mg that was introduced into FeP as "sacrificial dopant". The obtained Fevacancy-rich FeP nanoparticulate films, which were deposited on Ti foil, show excellent HER activity compared to pristine FeP and Mg-doped FeP, achieving a current density of 10 mA cm-2 at overpotentials of 108 mV in 1 m KOH and 65 mV in 0.5 m H2 SO4 , with a near-100 % Faradaic efficiency. Our theoretical and experimental analyses reveal that the improved HER activity originates from the presence of Fe vacancies, which lead to a synergistic modulation of the structural and electronic properties that result in a near-optimal hydrogen adsorption free energy and enhanced proton trapping. The success in catalytic improvement through the introduction of cationic vacancy defects has not only demonstrated the potential of Fe-vacancy-rich FeP as highly efficient, earth abundant HER catalyst, but also opens up an exciting pathway for activating other promising catalysts for electrochemical water splitting.

  • 14.
    Kwong, Wai Ling
    et al.
    KBC, Dept Chem, S-90187 Umea, Sweden..
    Lee, Cheng Choo
    Umea Univ, Umea Core Facil Electron Microscopy, S-90187 Umea, Sweden..
    Messinger, Johannes
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för kemi - Ångström, Molekylär biomimetik. KBC, Dept Chem, S-90187 Umea, Sweden..
    Scalable Two-Step Synthesis of Nickel Iron Phosphide Electrodes for Stable and Efficient Electrocatalytic Hydrogen Evolution2017Inngår i: The Journal of Physical Chemistry C, ISSN 1932-7447, E-ISSN 1932-7455, Vol. 121, nr 1, s. 284-292Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The development of efficient, durable, and inexpensive hydrogen evolution electrodes remains a key challenge for realizing a sustainable H-2 fuel production via electrocatalytic water splitting. Herein, nickel-iron phosphide porous films with precisely controlled metal content were synthesized on Ti foil using a simple and scalable two-step strategy of spray-pyrolysis deposition followed by low-temperature phosphidation. The nickel-iron phosphide of an optimized Ni:Fe ratio of 1:4 demonstrated excellent overall catalytic activity for hydrogen evolution reaction (HER) in 0.5 M H2SO4, achieving current densities of -10 and -30 mA cm(-2) at overpoteritials of 101 and 123 mV, respectively, with a Tafel slope of 43 mV dec(-1). Detailed analysis obtained by X-ray diffraction, electron microscopy, electrochemistry, and X-ray photoelectron spectroscopy revealed that the superior overall HER activity of nickel iron phosphide as compared to nickel phosphide and iron phosphide was a combined effect of differences in the morphology (real surface area) and the intrinsic catalytic properties (electronic structure). Together with a long-term stability and a near-100% Faradaic efficiency, the nickel-iron phosphide electrodes produced in this study provide blueprints for large-scale H-2 production.

  • 15.
    Kwong, Wai Ling
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för kemi - Ångström, Molekylär biomimetik.
    Lee, Cheng Choo
    Umeå Core Facility for Electron Microscopy, Umeå University, 90187 Umeå, Sweden.
    Shchukarev, Andrey
    Department of Chemistry, Kemiskt Biologiskt Centrum (KBC), Umeå University, 90187 Umeå, Sweden.
    Björn, Erik
    Department of Chemistry, Kemiskt Biologiskt Centrum (KBC), Umeå University, 90187 Umeå, Sweden.
    Messinger, Johannes
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för kemi - Ångström, Molekylär biomimetik. Department of Chemistry, Kemiskt Biologiskt Centrum (KBC), Umeå University, 90187 Umeå, Sweden.
    High-performance iron (III) oxide electrocatalyst for water oxidation in strongly acidic media2018Inngår i: Journal of Catalysis, ISSN 0021-9517, E-ISSN 1090-2694, Vol. 365, s. 29-35Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Stable and efficient oxygen evolution reaction (OER) catalysts for the oxidation of water to dioxygen in highly acidic media are currently limited to expensive noble metal (Ir and Ru) oxides since presentlyknown OER catalysts made of inexpensive earth-abundant materials generally suffer anodic corrosion at low pH. In this study, we report that a mixed-polymorph film comprising maghemite and hematite, prepared using spray pyrolysis deposition followed by low-temperature annealing, showed a sustained OER rate (>24 h) corresponding to a current density of 10 mA cm2 at an initial overpotential of 650mV, with a Tafel slope of only 56 mV dec1 and near-100% Faradaic efficiency in 0.5 M H2SO4 (pH 0.3). This performance is remarkable, since iron (III) oxide films comprising only maghemite were found toexhibit a comparable intrinsic activity, but considerably lower stability for OER, while films of pure hematite were OER-inactive. These results are explained by the differences in the polymorph crystal structures, which cause different electrical conductivity and surface interactions with water molecules and protons. Our findings not only reveal the potential of iron (III) oxide as acid-stable OER catalyst, but also highlight the important yet hitherto largely unexplored effect of crystal polymorphism on electrocatalytic OER performance.

  • 16.
    Kwong, Wai Ling
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för kemi - Ångström, Molekylär biomimetik.
    Lee, Cheng Choo
    Umeå Core Facility for Electron Microscopy, Umeå University, 90187 Umeå, Sweden.
    Shchukarev, Andrey
    Department of Chemistry, Kemiskt Biologiskt Centrum (KBC), Umeå University, 90187 Umeå, Sweden.
    Messinger, Johannes
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för kemi - Ångström, Molekylär biomimetik. Department of Chemistry, Kemiskt Biologiskt Centrum (KBC), Umeå University, Umeå, Sweden .
    Cobalt-doped hematite thin films for electrocatalytic water oxidation in highly acidic media2019Inngår i: Chemical Communications, ISSN 1359-7345, E-ISSN 1364-548X, Vol. 55, s. 5017-5020Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Earth-abundant cobalt-doped hematite thin-film electrocatalysts were explored for acidic water oxidation. The strategically doped hematite produced a stable geometric current density of 10 mA cm−2 for up to 50 h at pH 0.3, as a result of Co-enhanced intrinsic catalytic activity and charge transport properties across the film matrix.

  • 17.
    Melder, Jens
    et al.
    Albert-Ludwigs-Universitat, Freiburg, Germany.
    Kwong, Wai Ling
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för kemi - Ångström, Molekylär biomimetik. Umeå Universitet, Umeå, Sweden.
    Shevela, Dmitriy
    Umeå Universitet, Umeå, Sweden.
    Messinger, Johannes
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för kemi - Ångström, Molekylär biomimetik. Umeå Universitet, Umeå, Sweden.
    Kurz, Philipp
    Albert-Ludwigs-Universitat Freiburg, Germany.
    Electrocatalytic Water Oxidation by MnOx /C: In Situ Catalyst Formation, Carbon Substrate Variations, and Direct O2 /CO2 Monitoring by Membrane-Inlet Mass Spectrometry2017Inngår i: ChemSusChem, ISSN 1864-5631, E-ISSN 1864-564X, Vol. 10, nr 22, s. 4491-4502Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Layers of amorphous manganese oxides were directly formed on the surfaces of different carbon materials by exposing the carbon to aqueous solutions of permanganate (MnO4- ) followed by sintering at 100-400 °C. During electrochemical measurements in neutral aqueous buffer, nearly all of the MnOx /C electrodes show significant oxidation currents at potentials relevant for the oxygen evolution reaction (OER). However, by combining electrolysis with product detection by using mass spectrometry, it was found that these currents were only strictly linked to water oxidation if MnOx was deposited on graphitic carbon materials (faradaic O2 yields >90 %). On the contrary, supports containing sp3 -C were found to be unsuitable as the OER is accompanied by carbon corrosion to CO2 . Thus, choosing the "right" carbon material is crucial for the preparation of stable and efficient MnOx /C anodes for water oxidation catalysis. For MnOx on graphitic substrates, current densities of >1 mA cm-2 at η=540 mV could be maintained for at least 16 h of continuous operation at pH 7 (very good values for electrodes containing only abundant elements such as C, O, and Mn) and post-operando measurements proved the integrity of both the catalyst coating and the underlying carbon at OER conditions.

  • 18.
    Messinger, Johannes
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för kemi - Ångström, Molekylär biomimetik.
    From natural to artificial photosynthesis2017Konferansepaper (Annet vitenskapelig)
  • 19.
    Messinger, Johannes
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för kemi - Ångström, Molekylär biomimetik.
    From natural to artificial photosynthesis2017Konferansepaper (Annet vitenskapelig)
  • 20.
    Messinger, Johannes
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för kemi - Ångström, Molekylär biomimetik.
    Light-driven water oxidation by photosystem II2017Konferansepaper (Annet vitenskapelig)
  • 21.
    Messinger, Johannes
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för kemi - Ångström, Molekylär biomimetik.
    Optimizing the Metal Ratio in Nickel-Iron Phosphide Electrodes for Stable and Efficient Electrocatalytic Hydrogen Evolution2016Konferansepaper (Annet vitenskapelig)
  • 22.
    Messinger, Johannes
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för kemi - Ångström, Molekylär biomimetik.
    Water splitting catalyzed by the MN4CaO5 cluster in photosystem II2017Konferansepaper (Annet vitenskapelig)
  • 23.
    Messinger, Johannes
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för kemi - Ångström, Molekylär biomimetik.
    Ishitani, Osamu
    Tokyo Inst Technol, Dept Chem, Meguro Ku, O Okayama 2-12-1,E1-9, Tokyo 1528550, Japan.
    Wang, Dunwei
    Boston Coll, Merkert Chem Ctr, 2609 Beacon St, Chestnut Hill, MA 02467 USA.
    Artificial photosynthesis - from sunlight to fuels and valuable products for a sustainable future2018Inngår i: SUSTAINABLE ENERGY & FUELS, ISSN 2398-4902, Vol. 2, nr 9, s. 1891-1892Artikkel i tidsskrift (Annet vitenskapelig)
  • 24.
    Pham, Long Vo
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för kemi - Ångström, Molekylär biomimetik.
    Olmos, Julian David Janna
    Univ Warsaw, Ctr New Technol, Solar Fuels Lab, Banacha 2C, PL-02097 Warsaw, Poland;Jagiellonian Univ, Fac Biochem Biophys & Biotechnol, Dept Mol Biophys, Gronostajowa 7, PL-30387 Krakow, Poland.
    Chernev, Petko
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för kemi - Ångström, Molekylär biomimetik.
    Kargul, Joanna
    Univ Warsaw, Ctr New Technol, Solar Fuels Lab, Banacha 2C, PL-02097 Warsaw, Poland.
    Messinger, Johannes
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för kemi - Ångström, Molekylär biomimetik. Umea Univ, Chem Biol Ctr KBC, Dept Chem, Linnaeus Vag 6, S-90187 Umea, Sweden.
    Unequal misses during the flash-induced advancement of photosystem II: effects of the S state and acceptor side cycles2019Inngår i: Photosynthesis Research, ISSN 0166-8595, E-ISSN 1573-5079, Vol. 139, nr 1-3, s. 93-106Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Photosynthetic water oxidation is catalyzed by the oxygen-evolving complex (OEC) in photosystem II (PSII). This process is energetically driven by light-induced charge separation in the reaction center of PSII, which leads to a stepwise accumulation of oxidizing equivalents in the OEC (S-i states, i=0-4) resulting in O-2 evolution after each fourth flash, and to the reduction of plastoquinone to plastoquinol on the acceptor side of PSII. However, the S-i-state advancement is not perfect, which according to the Kok model is described by miss-hits (misses). These may be caused by redox equilibria or kinetic limitations on the donor (OEC) or the acceptor side. In this study, we investigate the effects of individual S state transitions and of the quinone acceptor side on the miss parameter by analyzing the flash-induced oxygen evolution patterns and the S-2, S-3 and S-0 state lifetimes in thylakoid samples of the extremophilic red alga Cyanidioschyzon merolae. The data are analyzed employing a global fit analysis and the results are compared to the data obtained previously for spinach thylakoids. These two organisms were selected, because the redox potential of Q(A)/Q(A)(-) in PSII is significantly less negative in C. merolae (E-m=-104mV) than in spinach (E-m=-163mV). This significant difference in redox potential was expected to allow the disentanglement of acceptor and donor side effects on the miss parameter. Our data indicate that, at slightly acidic and neutral pH values, the E-m of Q(A)(-)/Q(A) plays only a minor role for the miss parameter. By contrast, the increased energy gap for the backward electron transfer from Q(A)(-) to Pheo slows down the charge recombination reaction with the S-3 and S-2 states considerably. In addition, our data support the concept that the S-2 S-3 transition is the least efficient step during the oxidation of water to molecular oxygen in the Kok cycle of PSII.

  • 25.
    Shevela, Dmitry
    et al.
    Umea Univ, Chem Biol Ctr, Dept Chem, S-90187 Umea, Sweden.
    Ananyev, Gennady
    Rutgers State Univ, Waksman Inst Microbiol, Piscataway, NJ 08854 USA;Rutgers State Univ, Dept Chem & Chem Biol, Piscataway, NJ 08854 USA.
    Vatland, Ann K.
    Univ Stavanger, Fac Sci & Technol, Ctr Organelle Res, N-4036 Stavanger, Norway.
    Arnold, Janine
    Univ Stavanger, Fac Sci & Technol, Ctr Organelle Res, N-4036 Stavanger, Norway.
    Mamedov, Fikret
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för kemi - Ångström, Molekylär biomimetik.
    Eichacker, Lutz A.
    Univ Stavanger, Fac Sci & Technol, Ctr Organelle Res, N-4036 Stavanger, Norway.
    Dismukes, G. Charles
    Rutgers State Univ, Waksman Inst Microbiol, Piscataway, NJ 08854 USA;Rutgers State Univ, Dept Chem & Chem Biol, Piscataway, NJ 08854 USA.
    Messinger, Johannes
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för kemi - Ångström, Molekylär biomimetik. Umea Univ, Chem Biol Ctr, Dept Chem, S-90187 Umea, Sweden.
    "Birth defects' of photosystem II make it highly susceptible to photodamage during chloroplast biogenesis2019Inngår i: Physiologia Plantarum: An International Journal for Plant Biology, ISSN 0031-9317, E-ISSN 1399-3054, Vol. 166, nr 1, s. 165-180Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    High solar flux is known to diminish photosynthetic growth rates, reducing biomass productivity and lowering disease tolerance. Photosystem II (PSII) of plants is susceptible to photodamage (also known as photoinactivation) in strong light, resulting in severe loss of water oxidation capacity and destruction of the water-oxidizing complex (WOC). The repair of damaged PSIIs comes at a high energy cost and requires de novo biosynthesis of damaged PSII subunits, reassembly of the WOC inorganic cofactors and membrane remodeling. Employing membrane-inlet mass spectrometry and O-2-polarography under flashing light conditions, we demonstrate that newly synthesized PSII complexes are far more susceptible to photodamage than are mature PSII complexes. We examined these PSII birth defects' in barley seedlings and plastids (etiochloroplasts and chloroplasts) isolated at various times during de-etiolation as chloroplast development begins and matures in synchronization with thylakoid membrane biogenesis and grana membrane formation. We show that the degree of PSII photodamage decreases simultaneously with biogenesis of the PSII turnover efficiency measured by O-2-polarography, and with grana membrane stacking, as determined by electron microscopy. Our data from fluorescence, Q(B)-inhibitor binding, and thermoluminescence studies indicate that the decline of the high-light susceptibility of PSII to photodamage is coincident with appearance of electron transfer capability Q(A)(-)Q(B) during de-etiolation. This rate depends in turn on the downstream clearing of electrons upon buildup of the complete linear electron transfer chain and the formation of stacked grana membranes capable of longer-range energy transfer.

  • 26.
    Tikhonov, K.
    et al.
    Russian Acad Sci, Inst Basic Biol Problems, Pushchino, Russia.
    Shevela, D.
    Umea Univ, Dept Chem, Chem Biol Ctr, Umea, Sweden.
    Klimov, V. V.
    Russian Acad Sci, Inst Basic Biol Problems, Pushchino, Russia.
    Messinger, Johannes
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för kemi - Ångström, Molekylär biomimetik. Umea Univ, Dept Chem, Chem Biol Ctr, Umea, Sweden.
    Quantification of bound bicarbonate in photosystem II#2018Inngår i: Photosynthetica (Praha), ISSN 0300-3604, E-ISSN 1573-9058, Vol. 56, nr 1, s. 210-216Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    In this study, we presented a new approach for quantification of bicarbonate (HCO3-) molecules bound to PSII. Our method, which is based on a combination of membrane-inlet mass spectrometry (MIMS) and O-18-labelling, excludes the possibility of "non-accounted" HCO3- by avoiding (1) the employment of formate for removal of HCO3- from PSII, and (2) the extremely low concentrations of HCO3-/CO2 during online MIMS measurements. By equilibration of PSII sample to ambient CO2 concentration of dissolved CO2/HCO3-, the method ensures that all physiological binding sites are saturated before analysis. With this approach, we determined that in spinach PSII membrane fragments 1.1 +/- 0.1 HCO3- are bound per PSII reaction center, while none was bound to isolated PsbO protein. Our present results confirmed that PSII binds one HCO3- molecule as ligand to the non-heme iron of PSII, while unbound HCO3- optimizes the water-splitting reactions by acting as a mobile proton shuttle.

  • 27.
    Young, Iris D.
    et al.
    Lawrence Berkeley Natl Lab, Mol Biophys & Integrated Bioimaging Div, Berkeley, CA 94720 USA..
    Ibrahim, Mohamed
    Humboldt Univ, Inst Biol, D-10099 Berlin, Germany..
    Chatterjee, Ruchira
    Lawrence Berkeley Natl Lab, Mol Biophys & Integrated Bioimaging Div, Berkeley, CA 94720 USA..
    Gul, Sheraz
    Lawrence Berkeley Natl Lab, Mol Biophys & Integrated Bioimaging Div, Berkeley, CA 94720 USA..
    Fuller, Franklin D.
    Lawrence Berkeley Natl Lab, Mol Biophys & Integrated Bioimaging Div, Berkeley, CA 94720 USA..
    Koroidov, Sergey
    Umea Univ, Inst Kemi, Kemiskt Biol Ctr, S-90187 Umea, Sweden..
    Brewster, Aaron S.
    Lawrence Berkeley Natl Lab, Mol Biophys & Integrated Bioimaging Div, Berkeley, CA 94720 USA..
    Tran, Rosalie
    Lawrence Berkeley Natl Lab, Mol Biophys & Integrated Bioimaging Div, Berkeley, CA 94720 USA..
    Alonso-Mori, Roberto
    SLAC Natl Accelerator Lab, LCLS, Menlo Pk, CA 94025 USA..
    Kroll, Thomas
    SLAC Natl Accelerator Lab, Stanford PULSE Inst, Menlo Pk, CA 94025 USA.;SLAC Natl Accelerator Lab, SSRL, Menlo Pk, CA 94025 USA..
    Michels-Clark, Tara
    Lawrence Berkeley Natl Lab, Mol Biophys & Integrated Bioimaging Div, Berkeley, CA 94720 USA..
    Laksmono, Hartawan
    SLAC Natl Accelerator Lab, Stanford PULSE Inst, Menlo Pk, CA 94025 USA..
    Sierra, Raymond G.
    SLAC Natl Accelerator Lab, LCLS, Menlo Pk, CA 94025 USA.;SLAC Natl Accelerator Lab, Stanford PULSE Inst, Menlo Pk, CA 94025 USA..
    Stan, Claudiu A.
    SLAC Natl Accelerator Lab, Stanford PULSE Inst, Menlo Pk, CA 94025 USA..
    Hussein, Rana
    Humboldt Univ, Inst Biol, D-10099 Berlin, Germany..
    Zhang, Miao
    Humboldt Univ, Inst Biol, D-10099 Berlin, Germany..
    Douthit, Lacey
    Lawrence Berkeley Natl Lab, Mol Biophys & Integrated Bioimaging Div, Berkeley, CA 94720 USA..
    Kubin, Markus
    Helmholtz Zentrum, Inst Methods & Instrumentat Synchrotron Radiat Re, D-14109 Berlin, Germany..
    de Lichtenberg, Casper
    Umea Univ, Inst Kemi, Kemiskt Biol Ctr, S-90187 Umea, Sweden..
    Pham, Long Vo
    Nilsson, Hakan
    Umea Univ, Inst Kemi, Kemiskt Biol Ctr, S-90187 Umea, Sweden..
    Cheah, Mun Hon
    Umea Univ, Inst Kemi, Kemiskt Biol Ctr, S-90187 Umea, Sweden..
    Shevela, Dmitriy
    Umea Univ, Inst Kemi, Kemiskt Biol Ctr, S-90187 Umea, Sweden..
    Saracini, Claudio
    Lawrence Berkeley Natl Lab, Mol Biophys & Integrated Bioimaging Div, Berkeley, CA 94720 USA..
    Bean, Mackenzie A.
    Lawrence Berkeley Natl Lab, Mol Biophys & Integrated Bioimaging Div, Berkeley, CA 94720 USA..
    Seuffert, Ina
    Humboldt Univ, Inst Biol, D-10099 Berlin, Germany..
    Sokaras, Dimosthenis
    SLAC Natl Accelerator Lab, SSRL, Menlo Pk, CA 94025 USA..
    Weng, Tsu-Chien
    SLAC Natl Accelerator Lab, SSRL, Menlo Pk, CA 94025 USA.;Ctr High Pressure Sci & Technol Adv Res, Shanghai 201203, Peoples R China..
    Pastor, Ernest
    Lawrence Berkeley Natl Lab, Mol Biophys & Integrated Bioimaging Div, Berkeley, CA 94720 USA..
    Weninger, Clemens
    SLAC Natl Accelerator Lab, Stanford PULSE Inst, Menlo Pk, CA 94025 USA..
    Fransson, Thomas
    SLAC Natl Accelerator Lab, Stanford PULSE Inst, Menlo Pk, CA 94025 USA..
    Lassalle, Louise
    Lawrence Berkeley Natl Lab, Mol Biophys & Integrated Bioimaging Div, Berkeley, CA 94720 USA..
    Braeuer, Philipp
    Univ Oxford, Dept Biochem, S Parks Rd, Oxford OX1 3QU, England.;Diamond Light Source Ltd, Harwell Sci & Innovat Campus, Didcot OX11 0DE, Oxon, England..
    Aller, Pierre
    Diamond Light Source Ltd, Harwell Sci & Innovat Campus, Didcot OX11 0DE, Oxon, England..
    Docker, Peter T.
    Diamond Light Source Ltd, Harwell Sci & Innovat Campus, Didcot OX11 0DE, Oxon, England..
    Andi, Babak
    Brookhaven Natl Lab, Natl Synchrotron Light Source 2, Upton, NY 11973 USA..
    Orville, Allen M.
    Diamond Light Source Ltd, Harwell Sci & Innovat Campus, Didcot OX11 0DE, Oxon, England..
    Glownia, James M.
    SLAC Natl Accelerator Lab, LCLS, Menlo Pk, CA 94025 USA..
    Nelson, Silke
    SLAC Natl Accelerator Lab, LCLS, Menlo Pk, CA 94025 USA..
    Sikorski, Marcin
    SLAC Natl Accelerator Lab, LCLS, Menlo Pk, CA 94025 USA..
    Zhu, Diling
    SLAC Natl Accelerator Lab, LCLS, Menlo Pk, CA 94025 USA..
    Hunter, Mark S.
    SLAC Natl Accelerator Lab, LCLS, Menlo Pk, CA 94025 USA..
    Lane, Thomas J.
    SLAC Natl Accelerator Lab, LCLS, Menlo Pk, CA 94025 USA..
    Aquila, Andy
    SLAC Natl Accelerator Lab, LCLS, Menlo Pk, CA 94025 USA..
    Koglin, Jason E.
    SLAC Natl Accelerator Lab, LCLS, Menlo Pk, CA 94025 USA..
    Robinson, Joseph
    SLAC Natl Accelerator Lab, LCLS, Menlo Pk, CA 94025 USA..
    Liang, Mengning
    SLAC Natl Accelerator Lab, LCLS, Menlo Pk, CA 94025 USA..
    Boutet, Sebastien
    SLAC Natl Accelerator Lab, LCLS, Menlo Pk, CA 94025 USA..
    Lyubimov, Artem Y.
    Stanford Univ, Dept Mol & Cellular Physiol, Stanford, CA 94305 USA.;Stanford Univ, Howard Hughes Med Inst, Stanford, CA 94305 USA..
    Uervirojnangkoorn, Monarin
    Stanford Univ, Dept Mol & Cellular Physiol, Stanford, CA 94305 USA.;Stanford Univ, Howard Hughes Med Inst, Stanford, CA 94305 USA..
    Moriarty, Nigel W.
    Lawrence Berkeley Natl Lab, Mol Biophys & Integrated Bioimaging Div, Berkeley, CA 94720 USA..
    Liebschner, Dorothee
    Lawrence Berkeley Natl Lab, Mol Biophys & Integrated Bioimaging Div, Berkeley, CA 94720 USA..
    Afonine, Pavel V.
    Lawrence Berkeley Natl Lab, Mol Biophys & Integrated Bioimaging Div, Berkeley, CA 94720 USA..
    Waterman, David G.
    STFC Rutherford Appleton Lab, Didcot OX11 0QX, Oxon, England.;Rutherford Appleton Lab, CCP4,Res Complex Harwell, Didcot OX11 0FA, Oxon, England..
    Evans, Gwyndaf
    Diamond Light Source Ltd, Harwell Sci & Innovat Campus, Didcot OX11 0DE, Oxon, England..
    Wernet, Philippe
    Helmholtz Zentrum, Inst Methods & Instrumentat Synchrotron Radiat Re, D-14109 Berlin, Germany..
    Dobbek, Holger
    Humboldt Univ, Inst Biol, D-10099 Berlin, Germany..
    Weis, William I.
    Stanford Univ, Dept Mol & Cellular Physiol, Stanford, CA 94305 USA.;Stanford Univ, Dept Photon Sci, Stanford, CA 94305 USA.;Stanford Univ, Dept Struct Biol, Stanford, CA 94305 USA..
    Brunger, Axel T.
    Stanford Univ, Dept Mol & Cellular Physiol, Stanford, CA 94305 USA.;Stanford Univ, Howard Hughes Med Inst, Stanford, CA 94305 USA.;Stanford Univ, Dept Photon Sci, Stanford, CA 94305 USA.;Stanford Univ, Dept Struct Biol, Stanford, CA 94305 USA..
    Zwart, Petrus H.
    Lawrence Berkeley Natl Lab, Mol Biophys & Integrated Bioimaging Div, Berkeley, CA 94720 USA..
    Adams, Paul D.
    Univ Calif Berkeley, Dept Bioengn, Berkeley, CA 94720 USA..
    Zouni, Athina
    Humboldt Univ, Inst Biol, D-10099 Berlin, Germany..
    Messinger, Johannes
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för kemi - Ångström, Molekylär biomimetik. Umea Univ, Inst Kemi, Kemiskt Biol Ctr, S-90187 Umea, Sweden..
    Bergmann, Uwe
    SLAC Natl Accelerator Lab, Stanford PULSE Inst, Menlo Pk, CA 94025 USA..
    Sauter, Nicholas K.
    Lawrence Berkeley Natl Lab, Mol Biophys & Integrated Bioimaging Div, Berkeley, CA 94720 USA..
    Kern, Jan
    SLAC Natl Accelerator Lab, LCLS, Menlo Pk, CA 94025 USA..
    Yachandra, Vittal K.
    Lawrence Berkeley Natl Lab, Mol Biophys & Integrated Bioimaging Div, Berkeley, CA 94720 USA..
    Yano, Junko
    Lawrence Berkeley Natl Lab, Mol Biophys & Integrated Bioimaging Div, Berkeley, CA 94720 USA..
    Structure of photosystem II and substrate binding at room temperature2016Inngår i: Nature, ISSN 0028-0836, E-ISSN 1476-4687, Vol. 540, nr 7633, s. 453-457Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Light-induced oxidation of water by photosystem II (PS II) in plants, algae and cyanobacteria has generated most of the dioxygen in the atmosphere. PS II, a membrane-bound multi-subunit pigment protein complex, couples the one-electron photochemistry at the reaction centre with the four-electron redox chemistry of water oxidation at the Mn4CaO5 cluster in the oxygen-evolving complex (OEC). Under illumination, the OEC cycles through five intermediate S-states (S-0 to S-4)(1), in which S-1 is the dark-stable state and S-3 is the last semi-stable state before O-O bond formation and O-2 evolution(2,3). A detailed understanding of the O-O bond formation mechanism remains a challenge, and will require elucidation of both the structures of the OEC in the different S-states and the binding of the two substrate waters to the catalytic site(4-6). Here we report the use of femtosecond pulses from an X-ray free electron laser (XFEL) to obtain damage-free, room temperature structures of dark-adapted (S-1), two-flash illuminated (2F; S-3-enriched), and ammonia-bound two-flash illuminated (2F-NH3; S-3-enriched) PS II. Although the recent 1.95 angstrom resolution structure of PS II at cryogenic temperature using an XFEL7 provided a damage-free view of the S-1 state, measurements at room temperature are required to study the structural landscape of proteins under functional conditions(8,9), and also for in situ advancement of the S-states. To investigate the water-binding site(s), ammonia, a water analogue, has been used as a marker, as it binds to the Mn4CaO5 cluster in the S-2 and S-3 states(10). Since the ammonia-bound OEC is active, the ammonia-binding Mn site is not a substrate water site(10-13). This approach, together with a comparison of the native dark and 2F states, is used to discriminate between proposed O-O bond formation mechanisms.

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