• Title/Summary/Keyword: Max Planck

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Solid State NMR Studies of Proton Conducting Polymer, Poly(vinyl phosphonic) acid

  • Lee, Young-Joo;Bingol Bahar;Murakhtina Tatiana;Sebastiani Daniel;Ok, Jong-Hwa;Meyer Wolfgang H.;Wegner Gerhard;Spiess Hans Wolfgang
    • Proceedings of the Polymer Society of Korea Conference
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    • 2006.10a
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    • pp.347-347
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    • 2006
  • Polymers containing poly(vinyl phosphonic) acid segments are promising candidates to be used as proton conducting membranes. Solid state NMR spectroscopy represents an ideal probe of proton motion on the molecular level, because it allows us to selectively detect the nuclei of interest. In this paper, we apply solid state NMR methods to poly(vinyl phosphonic) acid in order to demonstrate that the proton conduction of poly(vinyl phosphonic acid) results from P-OH proton through hydrogen bonding and that the condensation of phosphonic acid leads to decrease in proton conductivity. $^{1}H\;and\;^{31}P$ solid state NMR experiments are supported by quantum chemical computation of NMR parameters.

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Transverse relaxation-optimized HCN experiment for tautomeric states of histidine sidechains

  • Schmidt, Holger;Himmel, Sebastian;Walter, Korvin F.A.;Klaukien, Volker;Funk, Michael;Lee, Dong-Han
    • Journal of the Korean Magnetic Resonance Society
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    • v.12 no.2
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    • pp.89-95
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    • 2008
  • Function of protein is frequently related with tautomeric states of histidine sidechains. Thus, several NMR experiments were developed to determine the tautomeric states of histidines. However, poor sensitivity of these experiments caused by long duration of magnetization transfer periods is unavoidable. Here, we alleviate the sensitivity of HCN experiment for determining the tautomeric states of histidine residues using TROSY principle to suppress transverse relaxation of $^{13}C$ spins during long polarization transfer delays involving $^{13}C-^{15}N$ scalar couplings. In addition, this experiment was used to assign the sidechain resonances of histidines. These assignments can be used to follow the pH-titration of histidine sidechains.

Sensitivity Enhancement of Methyl-TROSY by Longitudinal 1H Relaxation Optimization

  • Lee, Dong-Han;Vijayan, Vinesh;Montaville, Pierre;Becker, Stefan;Griesinger, Christian
    • Journal of the Korean Magnetic Resonance Society
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    • v.13 no.1
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    • pp.15-26
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    • 2009
  • The NMR detection of methyl groups is of keen interest because they provide the long-range distance information required to establish global folds of high molecular weight proteins. Using longitudinal $^1H$ relaxation optimization, we achieve a gain in sensitivity of approximately 1.6-fold in the methyl-TROSY and its NOESY experiments for the 38 kDa protein mitogen activated protein kinase p38 in its fully protonated and $^{13}C$ and $^{15}N$ labeled state.

Visualization of Candidate Division OP3 Cocci in Limonene-Degrading Methanogenic Cultures

  • Rotaru, Amelia-Elena;Schauer, Regina;Probian, Christina;Mussmann, Marc;Harder, Jens
    • Journal of Microbiology and Biotechnology
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    • v.22 no.4
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    • pp.457-461
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    • 2012
  • Members of candidate division OP3 were detected in 16S rRNA gene clone libraries from methanogenic enrichment cultures that utilized limonene as a carbon and energy source. We developed probes for the visualization of OP3 cells. In situ hybridization experiments with newly designed OP3-specific probes [OP3-565 and Eub-338(VI)] revealed abundant small OP3 cocci attached to larger cells. Syntrophic Deltaproteobacteria, OP3 cells, and methanogens affiliating with Methanoculleus and Methanosaeta formed the limonene-degrading community.