Now showing items 212-231 of 247

    • Screening and Design of Inhibitor Scaffolds for the Antibiotic Resistance Oxacillinase-48 (OXA-48) through Surface Plasmon Resonance Screening 

      Lund, Bjarte Aarmo; Christopeit, Tony; Guttormsen, Yngve; Bayer, Annette; Leiros, Hanna-Kirsti S. (Journal article; Tidsskriftartikkel; Peer reviewed, 2016-05-11)
      The spread of antibiotic resistant bacteria is a global threat that shakes the foundations of modern healthcare. β-Lactamases are enzymes that confer resistance to β-lactam antibiotics in bacteria, and there is a critical need for new inhibitors of these enzymes for combination therapy together with an antibiotic. With this in mind, we have screened a library of 490 fragments to identify starting ...
    • Screening of variable importance for optimizing electrodialytic remediation of heavy metals from polluted harbour sediments 

      Pedersen, Kristine Bondo; Lejon, Tore; Ottosen, Lisbeth M.; Jensen, Pernille E. (Journal article; Tidsskriftartikkel; Peer reviewed, 2015-04-15)
      Using multivariate design and modelling, optimal conditions for electrodialytic remediation (EDR) of heavy metals were determined for polluted harbour sediments from Hammerfest harbour located in the geographic Arctic region of Norway. The comparative importance of the variables; current density, remediation time, light/no light, the liquid-solid ratio and stirring rate of the sediment suspension ...
    • Sensitive on-chip methane detection with a cryptophane-A cladded Mach-Zehnder interferometer 

      Dullo, Firehun Tsige; Lindecrantz, Susan; Jagerska, Jana; Hansen, Jørn H; Engqvist, Stig Olov Magnus; Solbø, Stian; Hellesø, Olav Gaute (Journal article; Tidsskriftartikkel; Peer reviewed, 2015-11-24)
      We report a methane sensor based on an integrated Mach-Zehnder interferometer, which is cladded by a styrene-acrylonitrile film incorporating cryptophane-A. Cryptophane-A is a supramolecular compound able to selectively trap methane, and its presence in the cladding leads to a 17-fold sensitivity enhancement. Our approach, based on 3 cm-long low-loss Si3N4 rib waveguides, results in a detection limit ...
    • Shape-dependent electronic excitations in metallic chains 

      Gao, Bin; Ruud, Kenneth; Luo, Yi (Journal article; Tidsskriftartikkel; Peer reviewed, 2014)
    • Simultaneous electrodialytic removal of PAH, PCB, TBT and heavy metals from sediments 

      Pedersen, Kristine; Lejon, Tore; Jensen, Pernille E.; Ottosen, Lisbeth M. (Journal article; Tidsskriftartikkel; Peer reviewed, 2017-04-29)
      Contaminated sediments are remediated in order to protect human health and the environment, with the additional benefit of using the treated sediments for other activities. Common for many polluted sediments is the contamination with several different pollutants, making remediation challenging with the need of different remedial actions for each pollutant. In this study, electrodialytic remediation ...
    • Solvation at surfaces and interfaces: A quantum-mechanical/continuum approach including nonelectrostatic contributions 

      Mozgawa, Krzysztof; Mennucci, Benedetta; Frediani, Luca (Journal article; Tidsskriftartikkel; Peer reviewed, 2014-02-03)
    • Species diversity and abundance of shipworms (Mollusca: Bivalvia: Teredinidae) in woody marine debris generated by the Great East Japan Earthquake and Tsunami of 2011 

      Treneman, Nancy C.; Carlton, James T.; Borges, Luisa M. S.; Shipway, Reuben; Raupach, Michael; Altermark, Bjørn (Journal article; Tidsskriftartikkel; Peer reviewed, 2018-02)
      The Tohoku tsunami of March 2011 ejected a vast amount of debris into the Pacific Ocean. Wood boring shipworms (Bivalvia: Teredinidae) were either already present in, or settled on, the wooden fraction of this debris, offering a unique opportunity to study shipworm diversity in rafted wood of a known origin and time of ocean entry. Lumber and other wood began appearing on Central Pacific (Hawaiian ...
    • Spin-rotation and NMR shielding constants in HCl 

      Jaszunski, Michal; Repisky, Michal; Demissie, Taye B.; Komorovsky, Stanislav; Malkin, Elena; Ruud, Kenneth; Garbacz, Piotr; Jackowski, Karol; Makulski, W (Journal article; Tidsskriftartikkel; Peer reviewed, 2013)
      The spin-rotation and nuclear magnetic shielding constants are analysed for both nuclei in the HCl molecule. Nonrelativistic ab initio calculations at the CCSD(T) level of approximation show that it is essential to include relativistic effects to obtain spin-rotation constants consistent with accurate experimental data. Our best estimates for the spin-rotation constants of 1H35Cl are CCl =−53.914 ...
    • The Spot 42 RNA: A regulatory small RNA with roles in the central metabolism 

      Haugen, Peik; Bækkedal, Cecilie (Journal article; Tidsskriftartikkel; Peer reviewed, 2015-09-01)
      The Spot 42 RNA is a 109 nucleotide long (in Escherichia coli) noncoding small regulatory RNA (sRNA) encoded by the spf (spot fourty-two) gene. spf is found in gamma-proteobacteria and the majority of experimental work on Spot 42 RNA has been performed using E. coli, and recently Aliivibrio salmonicida. In the cell Spot 42 RNA plays essential roles as a regulator in carbohydrate metabolism and uptake, ...
    • Stable Platinum(IV) Corroles: Synthesis, Molecular Structure, and Room-Temperature Near-IR Phosphorescence 

      Alemayehu, Abraham; McCormick, Laura J; Gagnon, Kevin J.; Borisov, Sergey M.; Ghosh, Abhik (Journal article; Tidsskriftartikkel; Peer reviewed, 2018-08-17)
      A series of stable Pt(IV) corrole complexes with the general formula Pt<sup>IV</sup>[TpXPC](<i>m/p</i>-C<sub>6</sub>H<sub>4</sub>CN)(py), where TpXPC<sup>3–</sup> is the trianion of a tris(<i>p</i>-X-phenyl)corrole and X = CF<sub>3</sub>, H, and CH<sub>3</sub>, has been synthesized, affording key physicochemical data on a rare and elusive class of metallocorroles. Single-crystal X-ray structures of ...
    • Stepwise Deoxygenation of Nitrite as a Route to Two Families of Ruthenium Corroles: Group 8 Periodic Trends and Relativistic Effects 

      Alemayehu, Abraham; Vazquez Lima, Hugo; Gagnon, Kevin J.; Ghosh, Abhik (Journal article; Tidsskriftartikkel; Peer reviewed, 2017-04-19)
      Given the many applications of ruthenium porphyrins, the rarity of ruthenium corroles and the underdeveloped state of their chemistry are clearly indicative of an area ripe for significant breakthroughs. The tendency of ruthenium corroles to form unreactive metal–metal-bonded dimers has been recognized as a key impediment in this area. Herein, by exposing free-base meso-tris(p-X-phenyl)corroles, ...
    • Structural and biochemical characterization of VIM-26 shows that Leu224 has implications for the substrate specificity of VIM metallo-β-lactamases 

      Leiros, Hanna-Kirsti S.; Edvardsen, Kine Susann Waade; Bjerga, Gro Elin Kjæreng; Samuelsen, Ørjan (Journal article; Tidsskriftartikkel; Peer reviewed, 2015-02-06)
      During the last decades antimicrobial resistance has become a global health problem. Metallo-β-lactamases (MBLs) which are broad-spectrum β-lactamases that inactivate virtually all β-lactams including carbapenems, are contributing to this health problem. In this study a novel MBL variant, termed VIM-26, identified in a Klebsiella pneumoniae isolate was studied. VIM-26 belongs to the Verona ...
    • Structural and thermodynamic insight into phenylalanine hydroxylase from the human pathogen Legionella pneumophila 

      Leiros, Hanna-Kirsti S.; Flydal, Marte Innselset; Martinez, Aurora (Journal article; Tidsskriftartikkel; Peer reviewed, 2013)
      Phenylalanine hydroxylase from Legionella pneumophila (lpPAH) has a major functional role in the synthesis of the pigment pyomelanin, which is a potential virulence factor. We present here the crystal structure of lpPAH, which is a dimeric enzyme that shows high thermostability, with a midpoint denat- uration temperature of 79 ◦C, and low substrate affinity. The structure revealed a dimerization ...
    • Structural insight into a CE15 esterase from the marine bacterial metagenome 

      De Santi, Concetta; Gani, Osman A. B. S. M.; Helland, Ronny; Williamson, Adele Kim (Journal article; Tidsskriftartikkel; Peer reviewed, 2017-12-08)
      The family 15 carbohydrate esterase (CE15) MZ0003, which derives from a marine Arctic metagenome, has a broader substrate scope than other members of this family. Here we report the crystal structure of MZ0003, which reveals that residues comprising the catalytic triad differ from previously-characterized fungal homologs, and resolves three large loop regions that are unique to this bacterial ...
    • Structural insights into TMB-1 and the role of residues 119 and 228 in substrate and inhibitor binding 

      Skagseth, Susann; Christopeit, Tony; Akhter, Sundus; Bayer, Annette; Samuelsen, Ørjan; Leiros, Hanna-Kirsti S. (Journal article; Tidsskriftartikkel; Peer reviewed, 2017-05-30)
      Metallo-β-lactamases (MBLs) threaten the effectiveness of β-lactam antibiotics, including carbapenems, and are a concern for global public health. β-Lactam/β-lactamase inhibitor combinations active against class A and class D carbapenemases are used, but no clinically useful MBL inhibitor is currently available. Tripoli metallo-β-lactamase-1 (TMB-1) and TMB-2 are members of MBL subclass B1a, where ...
    • Structural intermediates of a DNA-ligase complex illuminate the role of the catalytic metal ion and mechanism of phosphodiester bond formation 

      Williamson, Adele Kim; Leiros, Hanna-Kirsti S. (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-07-17)
      DNA ligases join adjacent 5′ phosphate (5′P) and 3′ hydroxyl (3′OH) termini of double-stranded DNA via a three-step mechanism requiring a nucleotide cofactor and divalent metal ion. Although considerable structural detail is available for the first two steps, less is known about step 3 where the DNA-backbone is joined or about the cation role at this step. We have captured high-resolution structures ...
    • Structure and function of a CE4 deacetylase isolated from a marine environment 

      Tuveng, Tina Rise; Rothweiler, Ulli; Udatha, D.B.R.K. Gupta; Vaaje-Kolstad, Gustav; Smalås, Arne O.; Eijsink, Vincent (Journal article; Tidsskriftartikkel; Peer reviewed, 2017-11-06)
      Chitin, a polymer of β(1–4)-linked N-acetylglucosamine found in e.g. arthropods, is a valuable resource that may be used to produce chitosan and chitooligosaccharides, two compounds with considerable industrial and biomedical potential. Deacetylating enzymes may be used to tailor the properties of chitin and its derived products. Here, we describe a novel CE4 enzyme originating from a marine ...
    • Structure determination of uracil-DNA N-glycosylase from Deinococcus radiodurans in complex with DNA 

      Pedersen, Hege Lynum; Johnson, Kenneth; McVey, Colin; Leiros, Ingar; Moe, Elin (Journal article; Tidsskriftartikkel; Peer reviewed, 2015-10-01)
    • The structure of a dual-specificity tyrosine phosphorylation-regulated kinase 1A-PKC412 complex reveals disulfide-bridge formation with the anomalous catalytic loop HRD(HCD) cysteine 

      Alexeeva, Marina; Åberg, espen; Engh, Richard Alan; Rothweiler, Ulli (Journal article; Tidsskriftartikkel; Peer reviewed, 2015)
      Dual-specificity tyrosine phosphorylation-regulated kinase 1A (DYRK1A) is a protein kinase associated with neuronal development and brain physiology. The DYRK kinases are very unusual with respect to the sequence of the catalytic loop, in which the otherwise highly conserved arginine of the HRD motif is replaced by a cysteine. This replacement, along with the proximity of a potential disulfide-bridge ...
    • The structure of the metallo-β-lactamase VIM-2 in complex with a triazolylthioacetamide inhibitor 

      Christopeit, Tony; Yang, Ke-Wu; Yang, Shao-Kang; Leiros, Hanna-Kirsti S. (Journal article; Tidsskriftartikkel; Peer reviewed, 2016-11)
      The increasing number of pathogens expressing metallo-β-lactamases (MBLs), and in this way achieving resistance to β-lactam antibiotics, is a significant threat to global public health. A promising strategy to treat such resistant pathogens is the co-administration of MBL inhibitors together with β-lactam antibiotics. However, an MBL inhibitor suitable for clinical use has not yet been identified. ...