@article{SramaKruegerYamaguchietal.2012, author = {Srama, Ralf and Krueger, H. and Yamaguchi, T. and Stephan, T. and Burchell, M. and Kearsley, A. T. and Sterken, V. and Postberg, F. and Kempf, S. and Gr{\"u}n, Eberhard and Altobelli, Nicolas and Ehrenfreund, P. and Dikarev, V. and Horanyi, M. and Sternovsky, Zoltan and Carpenter, J. D. and Westphal, A. and Gainsforth, Z. and Krabbe, A. and Agarwal, Jessica and Yano, H. and Blum, J. and Henkel, H. and Hillier, J. and Hoppe, P. and Trieloff, M. and Hsu, S. and Mocker, A. and Fiege, K. and Green, S. F. and Bischoff, A. and Esposito, F. and Laufer, R. and Hyde, T. W. and Herdrich, G. and Fasoulas, S. and Jaeckel, A. and Jones, G. and Jenniskens, P. and Khalisi, E. and Moragas-Klostermeyer, Georg and Spahn, Frank and Keller, H. U. and Frisch, P. and Levasseur-Regourd, A. C. and Pailer, N. and Altwegg, K. and Engrand, C. and Auer, S. and Silen, J. and Sasaki, S. and Kobayashi, M. and Schmidt, J. and Kissel, J. and Marty, B. and Michel, P. and Palumbo, P. and Vaisberg, O. and Baggaley, J. and Rotundi, A. and Roeser, H. P.}, title = {SARIM PLUS-sample return of comet 67P/CG and of interstellar matter}, series = {EXPERIMENTAL ASTRONOMY}, volume = {33}, journal = {EXPERIMENTAL ASTRONOMY}, number = {2-3}, publisher = {SPRINGER}, address = {DORDRECHT}, issn = {0922-6435}, doi = {10.1007/s10686-011-9285-7}, pages = {723 -- 751}, year = {2012}, abstract = {The Stardust mission returned cometary, interplanetary and (probably) interstellar dust in 2006 to Earth that have been analysed in Earth laboratories worldwide. Results of this mission have changed our view and knowledge on the early solar nebula. The Rosetta mission is on its way to land on comet 67P/Churyumov-Gerasimenko and will investigate for the first time in great detail the comet nucleus and its environment starting in 2014. Additional astronomy and planetary space missions will further contribute to our understanding of dust generation, evolution and destruction in interstellar and interplanetary space and provide constraints on solar system formation and processes that led to the origin of life on Earth. One of these missions, SARIM-PLUS, will provide a unique perspective by measuring interplanetary and interstellar dust with high accuracy and sensitivity in our inner solar system between 1 and 2 AU. SARIM-PLUS employs latest in-situ techniques for a full characterisation of individual micrometeoroids (flux, mass, charge, trajectory, composition()) and collects and returns these samples to Earth for a detailed analysis. The opportunity to visit again the target comet of the Rosetta mission 67P/Churyumov-Gerasimeenternko, and to investigate its dusty environment six years after Rosetta with complementary methods is unique and strongly enhances and supports the scientific exploration of this target and the entire Rosetta mission. Launch opportunities are in 2020 with a backup window starting early 2026. The comet encounter occurs in September 2021 and the reentry takes place in early 2024. An encounter speed of 6 km/s ensures comparable results to the Stardust mission.}, language = {en} } @article{ZaccheusBroekerLundborgetal.2012, author = {Zaccheus, Mona V. and Br{\"o}ker, Nina Kristin and Lundborg, Magnus and Uetrecht, Charlotte and Barbirz, Stefanie and Widmalm, Goran}, title = {Structural studies of the O-antigen polysaccharide from Escherichia coli TD2158 having O18 serogroup specificity and aspects of its interaction with the tailspike endoglycosidase of the infecting bacteriophage HK620}, series = {Carbohydrate research}, volume = {357}, journal = {Carbohydrate research}, number = {8}, publisher = {Elsevier}, address = {Oxford}, issn = {0008-6215}, doi = {10.1016/j.carres.2012.05.022}, pages = {118 -- 125}, year = {2012}, abstract = {We have analyzed the O-antigen polysaccharide of the previously uncharacterized Escherichia coli strain TD2158 which is a host of bacteriophage HK620. This bacteriophage recognizes and cleaves the polysaccharide with its tailspike protein (TSP). The polysaccharide preparation as well as oligosaccharides obtained from HK620TSP endoglycosidase digests were analyzed with NMR spectroscopy. Additionally, sugar analysis was performed on the O-antigen polysaccharide and MALDI-TOF MS was used in oligosaccharide analysis. The present study revealed a heterogeneous polysaccharide with a hexasaccharide repeating unit of the following structure: alpha-D-Glcp-(1 -> 6) vertical bar vertical bar 2)-alpha-L-Rhap-(1 -> 6)-alpha-D-Glcp-(1 -> 4)-alpha-D-Galp-(1 -> 3)-alpha-D-GlcpNAc- (1 ->vertical bar beta-D-Glcp/beta-D-GlcpNAc-(1 -> 3) A repeating unit with a D-GlcNAc substitution of D-Gal has been described earlier as characteristic for serogroup O18A1. Accordingly, we termed repeating units with D-Glc substitution at D-Gal as O18A2. NMR analyses of the polysaccharide confirmed that O18A1- and O18A2-type repeats were present in a 1:1 ratio. However, HK620TSP preferentially bound the D-GlcNAc- substituted O18A1-type repeating units in its high affinity binding pocket with a dissociation constant of 140 mu M and disfavored the O18A2-type having a beta-D-Glcp-(1 -> 3)-linked group. As a result, in hexasaccharide preparations, O18A1 and O18A2 repeats were present in a 9: 1 ratio stressing the clear preference of O18A1- type repeats to be cleaved by HK620TSP.}, language = {en} }