Studies of oligosaccharides and carbon-13 enriched bacterial polysaccharides using NMR spectroscopy and computer simulations
1998 (English)Doctoral thesis, comprehensive summary (Other academic)
The conformation and dynamics of the trisaccharide methyl β-D-Glcp-(1--> 2)[β-D-Glcp-(1 --> 3)] α-D-Manp and its constituent disaccharides methyl β-D-Glcp-(1 --> 2) α-D-Manp and methyl β-D-Glcp-(1 --> 3) α-D-Manp have been studied using computer simulations and NMR spectroscopy. The computer simulations applied were Metropolis Monte Carlo simulations employing the HSEA force field and Langevin dynamics simulations using the PARM22 and CHEAT95 force fileds. The NMR methods used were measurement of long-range heteronuclear coupling constants across the glycosidic linkages, measurement of carbon-13 nuclear relaxation rates for the determination of dynamical parameters according the Lipari-Szabo "model free" approach and measurements of homonuclear NOE and TROE cross relaxation rates for the determination of proton-proton distances. Experimental data were then compared to the corresponding parameters extracted from the various computer simulations.
Studies of the carbon-13 labelled O-polysaccharides from Escherichia coli O25 and O91 have also been performed. 13C-13C TOCSY experiments, with the spin-lock on the carbon-13 nuclei, were applied to sugar residues of different geometries. This circumvented the problem of hampered magnetisation transfer encountered in residues with 3JHH < 2Hz when the spin-lock is applied on the protons.The carbon-13 labelling was also used to demonstrate the biosynthesis of one of the substituents in the Escherichia coli O91 O-polysaccharide.
Place, publisher, year, edition, pages
Stockholm: Department of Organic Chemistry, Stockholm University , 1998. , 53 p.
Other Basic Medicine
Research subject Organic Chemistry
IdentifiersURN: urn:nbn:se:su:diva-37592ISBN: 91-7153-720-1OAI: oai:DiVA.org:su-37592DiVA: diva2:303908
1998-02-27, Magnélisalen, KÖL, Frescati, Stockholm, 10:00 (English)
Homans, Steven, Professor
Härtill 5 uppsatser2010-03-162010-03-162010-11-09Bibliographically approved