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  • 1.
    Esmieu, Charlène
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Molecular Biomimetics.
    Raleiras, Patricia
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Molecular Biomimetics.
    Berggren, Gustav
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Molecular Biomimetics.
    From protein engineering to artificial enzymes - biological and biomimetic approaches towards sustainable hydrogen production2018In: SUSTAINABLE ENERGY & FUELS, ISSN 2398-4902, Vol. 2, no 4, p. 724-750Article, review/survey (Refereed)
    Abstract [en]

    Hydrogen gas is used extensively in industry today and is often put forward as a suitable energy carrier due its high energy density. Currently, the main source of molecular hydrogen is fossil fuels via steam reforming. Consequently, novel production methods are required to improve the sustainability of hydrogen gas for industrial processes, as well as paving the way for its implementation as a future solar fuel. Nature has already developed an elaborate hydrogen economy, where the production and consumption of hydrogen gas is catalysed by hydrogenase enzymes. In this review we summarize efforts on engineering and optimizing these enzymes for biological hydrogen gas production, with an emphasis on their inorganic cofactors. Moreover, we will describe how our understanding of these enzymes has been applied for the preparation of bio-inspired/-mimetic systems for efficient and sustainable hydrogen production.

  • 2.
    Howe, Christoph
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Molecular Biomimetics.
    Ho, Felix
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Molecular Biomimetics.
    Nenninger, Anja
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Molecular Biomimetics.
    Raleiras, Patricia
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Molecular Biomimetics.
    Stensjö, Karin
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Molecular Biomimetics.
    Differential biochemical properties of three canonical Dps proteins from the cyanobacterium Nostoc punctiforme suggest distinct cellular functions2018In: Journal of Biological Chemistry, ISSN 0021-9258, E-ISSN 1083-351X, Vol. 293, no 43, p. 16635-16646Article in journal (Refereed)
    Abstract [en]

    DNA-binding proteins from starved cells (Dps, EC: 1.16.3.1) have a variety of different biochemical activities such as DNA-binding, iron sequestration, and H2O2 detoxification. Most bacteria commonly feature one or two Dps enzymes, whereas the cyanobacterium Nostoc punctiforme displays an unusually high number of five Dps proteins (NpDps1-5). Our previous studies have indicated physiological differences, as well as cell-specific expression, among these five proteins. Three of the five NpDps proteins, NpDps1, -2, and -3, were classified as canonical Dps proteins. To further investigate their properties and possible importance for physiological function, here we characterized and compared them in vitro Nondenaturing PAGE, gel filtration, and dynamic light-scattering experiments disclosed that the three NpDps proteins exist as multimeric protein species in the bacterial cell. We also demonstrate Dps-mediated iron oxidation catalysis in the presence of H2O2 However, no iron oxidation with O2 as the electron acceptor was detected under our experimental conditions. In modeled structures of NpDps1, -2, and -3, protein channels were identified that could serve as the entrance for ferrous iron into the dodecameric structures. Furthermore, we could demonstrate pH-dependent DNA-binding properties for NpDps2 and -3. This study adds critical insights into the functions and stabilities of the three canonical Dps proteins from N. punctiforme and suggests that each of the Dps proteins within this bacterium has a specific biochemical property and function.

  • 3.
    Khanna, Namita
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Molecular Biomimetics.
    Raleiras, Patrícia
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Molecular Biomimetics.
    Lindblad, Peter
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Molecular Biomimetics.
    Fundamentals and Recent Advances in Hydrogen Production and Nitrogen Fixation in Cyanobacteria2016In: The Physiology of Microalgae / [ed] Michael A. Borowitzka, John Beardall, John A. Raven, Switzerland: Springer International Publishing , 2016, p. 101-127Chapter in book (Other academic)
  • 4.
    Magnuson, Ann
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Molecular Biomimetics.
    Raleiras, Patricia
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Molecular Biomimetics.
    Hammarström, Leif
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Physical Chemistry.
    Styring, Stenbjörn
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Molecular Biomimetics.
    Laser flash photolysis induced electron transfer in the isolated uptake hydrogenase subunit HupS studied by EPR spectroscopy2014In: Journal of Biological Inorganic Chemistry, ISSN 0949-8257, E-ISSN 1432-1327, Vol. 19, no S2, p. 851-Article in journal (Other academic)
  • 5.
    Magnuson, Ann
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Molecular Biomimetics.
    Raleiras, Patricia
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Molecular Biomimetics.
    Meszaros, Livia S.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Molecular Biomimetics.
    Khanna, Namita
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Molecular Biomimetics.
    Miranda, Helder
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Molecular Biomimetics.
    Ho, Felix M.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Molecular Biomimetics.
    Lindblad, Peter
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Molecular Biomimetics.
    Styring, Stenbjörn
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Molecular Biomimetics.
    Sustainable photobiological hydrogen production via protein engineering of cyanobacterial hydrogenases2018In: Abstract of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 255Article in journal (Other academic)
  • 6.
    Moparthi, Vamsi
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Molecular Biomimetics. Linköping Univ, Div Chem, Dept Phys Chem & Biol, Linköping, Sweden.
    Moparthi, Satish B.
    Aix Marseille Univ, CNRS, Inst Fresnel, Cent Marseille, Marseille, France; Inst Pasteur, Membrane Biochem & Transport, Paris, France.
    Howe, Christoph
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Molecular Biomimetics.
    Raleiras, Patricia
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Molecular Biomimetics. Medicago AB, Uppsala, Sweden.
    Wenger, Jerome
    Aix Marseille Univ, CNRS, Inst Fresnel, Cent Marseille, Marseille, France.
    Stensjö, Karin
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Molecular Biomimetics.
    Structural diffusion properties of two atypical Dps from the cyanobacterium Nostoc punctiforme disclose interactions with ferredoxins and DNA2019In: Biochimica et Biophysica Acta - Bioenergetics, ISSN 0005-2728, E-ISSN 1879-2650, Vol. 1860, no 9, article id 148063Article in journal (Refereed)
    Abstract [en]

    Ferritin-like proteins, Dps (DNA-binding protein from starved cells), store iron and play a key role in the iron homeostasis in bacteria, yet their iron releasing machinery remains largely unexplored. The electron donor proteins that may interact with Dps and promote the mobilization of the stored iron have hitherto not been identified. Here, we investigate the binding capacity of the two atypical Dps proteins NpDps4 and NpDps5 from Nostoc punctiforme to isolated ferredoxins. We report NpDps-ferredoxin interactions by fluorescence correlation spectroscopy (FCS) and fluorescence resonance energy transfer (FRET) methods. Dynamic light scattering, size exclusion chromatography and native gel electrophoresis results show that NpDps4 forms a dodecamer at both pH 6.0 and pH 8.0, while NpDps5 forms a dodecamer only at pH 6.0. In addition, FCS data clearly reveal that the non-canonical NpDps5 interacts with DNA at pH 6.0. Our spectroscopic analysis shows that [FeS] centers of the three recombinantly expressed and isolated ferredoxins are properly incorporated and are consistent with their respective native states. The results support our hypothesis that ferredoxins could be involved in cellular iron homeostasis by interacting with Dps and assisting the release of stored iron.

  • 7.
    Raleiras, Patricia
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Molecular Biomimetics.
    Kellers, P.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström.
    Lindblad, Peter
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Molecular Biomimetics.
    Styring, Stenbjörn
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Molecular Biomimetics.
    Magnuson, Ann
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Molecular Biomimetics.
    Evidence for non-cysteinyl coordination of the iron-sulfur clusters of HupS, the small subunit of the uptake hydrogenase from Nostoc punctiforme2014In: Journal of Biological Inorganic Chemistry, ISSN 0949-8257, E-ISSN 1432-1327, Vol. 19, p. S259-S259Article in journal (Other academic)
  • 8.
    Raleiras, Patricia
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Molecular Biomimetics.
    Kellers, Petra
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström.
    Lindblad, Peter
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Molecular Biomimetics.
    Styring, Stenbjörn
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Molecular Biomimetics.
    Magnuson, Ann
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Molecular Biomimetics.
    Isolation and Characterization of the Small Subunit of the Uptake Hydrogenase from the Cyanobacterium Nostoc punctiforme.2013In: Journal of Biological Chemistry, ISSN 0021-9258, E-ISSN 1083-351X, Vol. 288, no 25, p. 18345-18352Article in journal (Refereed)
    Abstract [en]

     In nitrogen-fixing cyanobacteria, hydrogen evolution is associated with hydrogenases and nitrogenase, making these enzymes interesting targets for genetic engineering aimed at increased hydrogen production. Nostoc punctiforme ATCC 29133 is a filamentous cyanobacterium that expresses the uptake hydrogenase HupSL in heterocysts under nitrogen-fixing conditions. Little is known about the structural and biophysical properties of HupSL. The small subunit, HupS, has been postulated to contain three iron-sulfur clusters, but the details regarding their nature have been unclear due to unusual cluster binding motifs in the amino acid sequence. We now report the cloning and heterologous expression of Nostoc punctiforme HupS as a fusion protein, f-HupS. We have characterized the anaerobically purified protein by UV-visible and EPR spectroscopies. Our results show that f-HupS contains three iron-sulfur clusters. UV-visible absorption of f-HupS has bands similar to 340 and 420 nm, typical for iron-sulfur clusters. The EPR spectrum ofthe oxidized f-HupS shows a narrow g = 2.023 resonance, characteristic of a low-spin (S = 1/2) [3Fe-4S] cluster. The reduced f-HupS presents complex EPR spectra with overlapping resonances centered on g = 1.94, g = 1.91, and g = 1.88, typical of low-spin (S = 1/2) [4Fe-4S] clusters. Analysis of the spectroscopic data allowed us to distinguish between two species attributable to two distinct [4Fe-4S] clusters, in addition to the [3Fe-4S] cluster. This indicates that f-HupS binds [4Fe-4S] clusters despite the presence of unusual coordinating amino acids. Furthermore, our expression and purification of what seems to be an intact HupS protein allows future studies on the significance of ligand nature on redox properties ofthe iron-sulfur clusters of HupS.

  • 9.
    Raleiras, Patrícia
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Molecular Biomimetics.
    Hammarström, Leif
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Physical Chemistry.
    Lindblad, Peter
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Molecular Biomimetics.
    Styring, Stenbjörn
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Molecular Biomimetics.
    Magnuson, Ann
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Molecular Biomimetics.
    Photoinduced reduction of the medial FeS center in the hydrogenase small subunit HupS from Nostoc punctiforme2015In: Journal of Inorganic Biochemistry, ISSN 0162-0134, E-ISSN 1873-3344, Vol. 148, p. 57-61Article in journal (Refereed)
    Abstract [en]

    The small subunit from the NiFe uptake hydrogenase, HupSL, in the cyanobacterium Nostoc punctiforme ATCC 29133, has been isolated in the absence of the large subunit (P. Raleiras, P. Kellers, P. Lindblad, S. Styring, A. Magnuson, J. Biol. Chem. 288 (2013) 18,345-18,352). Here, we have used flash photolysis to reduce the iron-sulfur clusters in the isolated small subunit, HupS. We used ascorbate as electron donor to the photogenerated excited state of Ru(II)-trisbipyridine (Ru(bpy)3), to generate Ru(I)(bpy)3 as reducing agent. Our results show that the isolated small subunit can be reduced by the Ru(I)(bpy)3 generated through flash photolysis.

  • 10.
    Raleiras, Patrícia
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Molecular Biomimetics.
    Khanna, Namita
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Molecular Biomimetics.
    Miranda, Helder
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Molecular Biomimetics.
    Meszaros, Livia S.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Molecular Biomimetics.
    Krassen, Henning
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Molecular Biomimetics.
    Ho, Felix
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Molecular Biomimetics.
    Battchikova, Natalia
    Turku University.
    Aro, Eva-Mari
    Turku University.
    Magnuson, Ann
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Molecular Biomimetics.
    Lindblad, Peter
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Molecular Biomimetics.
    Styring, Stenbjörn
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Molecular Biomimetics.
    Turning around the electron flow in an uptake hydrogenase. EPR spectroscopy and in vivo activity of a designed mutant in HupSL from Nostoc punctiforme2016In: Energy & Environmental Science, ISSN 1754-5692, E-ISSN 1754-5706, Vol. 9, no 2, p. 581-594Article in journal (Refereed)
    Abstract [en]

    The filamentous cyanobacterium Nostoc punctiforme ATCC 29133 produces hydrogen via nitrogenase in heterocysts upon onset of nitrogen-fixing conditions. N. punctiforme expresses concomitantly the uptake hydrogenase HupSL, which oxidizes hydrogen in an effort to recover some of the reducing power used up by nitrogenase. Eliminating uptake activity has been employed as a strategy for net hydrogen production in N. punctiforme (Lindberg et al., Int. J. Hydrogen Energy, 2002, 27, 1291-1296). However, nitrogenase activity wanes within a few days. In the present work, we modify the proximal iron-sulfur cluster in the hydrogenase small subunit HupS by introducing the designed mutation C12P in the fusion protein f-HupS for expression in E. coli (Raleiras et al., J. Biol. Chem., 2013, 288, 18345-18352), and in the full HupSL enzyme for expression in N. punctiforme. C12P f-HupS was investigated by EPR spectroscopy and found to form a new paramagnetic species at the proximal cluster site consistent with a [4Fe-4S] to [3Fe-4S] cluster conversion. The new cluster has the features of an unprecedented mixed-coordination [3Fe-4S] metal center. The mutation was found to produce stable protein in vitro, in silico and in vivo. When C12P HupSL was expressed in N. punctiforme, the strain had a consistently higher hydrogen production than the background [capital Delta]hupSL mutant. We conclude that the increase in hydrogen production is due to the modification of the proximal iron-sulfur cluster in HupS, leading to a turn of the electron flow in the enzyme.

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