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1
Dücker, Eibe Behrend. "Enhancement Strategies in NMR Spectroscopy". Doctoral thesis, Niedersächsische Staats- und Universitätsbibliothek Göttingen, 2018. http://hdl.handle.net/11858/00-1735-0000-002E-E3E4-9.
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Stonehouse, Jonathan. "New techniques in NMR spectroscopy". Thesis, University of Cambridge, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.360628.
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Hughes, Colan Evan. "New techniques in NMR spectroscopy". Thesis, University of Oxford, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.297524.
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4
Fulwood, Russell. "Chiral analysis by NMR spectroscopy". Thesis, Durham University, 1992. http://etheses.dur.ac.uk/5979/.
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The analysis of the enantiomeric purity of chiral carboxylic acids requires a reagent to give acceptable NMR chemical shift non-equivalence with a wide range of substrate acids. Extensive studies of the behaviour of N-mono- methyl, N,N-dimethyl and cyclic amines as chiral solvating agents led to the finding that 1,2 diphenyl-1,2-diaminoethane can induce substantial non- equivalence in the diastereomeric salts of chiral a-phenyl and a-halo carboxylic acids. The diastereoisomeric complexes of the diamine with primary carboxylic acids (RCH(_2)CO(_2)H) presents an unusual case in which the internally enantiotopic methylene protons are rendered internally diasteretopic by an external non-covalently bonded reagent. Investigations of the physical parameters determining non-equivalence (stoichiometry, concentration, temperature and substrate enantiomeric purity), combined with NOE observations of the diastereomeric pairs and the crystal structure of the mono- hydrobromide salt were used to suggest the structure for the conformation responsible for shift non-equivalence. The zero valent platinum complex, 3-0-isopropylidene-2,3-dihydroxy-1,4- bis(diphenyl-phosphino)butane-platinum(0)-ethene (DlOP-Pt-ethene) was shown to be a versatile chiral derivatising agent for electron poor and strained η(^2)-donors. This was demonstrated by the enantiomeric purity determinations for alkynes, enones and norbornene derivatives. The crystal structure of DIOP-Pt-ethene was determined and found to be similar to the palladium analogue. If the achiral rhodium complex rhodium(I)-acetylacetone-diethene undergoes a reaction with 2 equivalents of a suitable chiral η(^2)-donor, it will result in the formation of 4 stereoisomers, two meso forms and a pair of enantiomers. The diasteroisomers should display chemical shift non-equivalence in the NMR spectrum of the product, reflecting the enantiomeric purity of the η(^2)-donor (self recognition). The derivatisation of rhodium(l)-acetylacetone-diethene with chiral η(^2)-donors was attempted.
5
Edden, Richard Anthony Edward. "New methods in NMR spectroscopy". Thesis, University of Cambridge, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.613719.
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Zhu, Jian-Ming. "Spatially localized proton NMR correlation spectroscopy". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/nq23681.pdf.
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Nordstierna, Lars. "Molecular Association Studied by NMR Spectroscopy". Doctoral thesis, Stockholm : Physical Chemistry, Department of Chemistry, Royal Institute of Technology, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-3947.
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Kenwright, A. "Applications of NMR spectroscopy to solids". Thesis, University of East Anglia, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.482971.
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Ha, Dongwan. "Scalable NMR Spectroscopy with Semiconductor Chips". Thesis, Harvard University, 2014. http://dissertations.umi.com/gsas.harvard:11635.
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Conventional nuclear magnetic resonance (NMR) spectrometers—the electronic brain that orchestrates and monitors nuclear spin motions—are bulky, expensive, thus, not scalable. In this thesis, we report on scalable 4-mm2 silicon spectrometer chips that perform a broad range of two-dimensional NMR spectroscopy—e.g., correlation spectroscopy, J-resolved spectroscopy, and heteronuclear quantum coherence spectroscopy—as well as one-dimensional spectroscopy and relaxometry. In this way, they examine a wealth of nuclear spin behaviors and interactions in biological, organic, and pharmaceutical compound molecules, elucidating their structures and dynamics. This semiconductor-based NMR spectroscopy opens up new exciting vistas with two prime advantages. First, with size/cost economy and scalability, the spectrometer chips can be parallelized sharing the same bore of a magnet—whether a large superconducting or small permanent magnet—to greatly simplify multi-channel spectroscopy and vastly increase the spectroscopy throughput, overcoming the intrinsic slowness of NMR spectroscopy; such parallelism may enable the much-desired high-throughput NMR paradigm for drug discovery, metabolomics/metabonomics, and structural biology. We demonstrate the concept of this parallelism by 2-channel heteronuclear quantum coherence NMR experiments, where 2 chips run synchronously in an ultra-compact configuration. Second, the chip spectrometers can complement the recent advance in magnet miniaturization to realize bona fide portable NMR spectroscopy systems. To demonstrate this miniaturization benefit (in addition to the orthogonal benefit of parallelism), we perform all our spectroscopy experiments in a platform combining the spectrometer chips with a compact permanent NdFeB magnet. These demonstrations suggest new dimensions to the technology and applications of NMR spectroscopy enabled by the integrated spectrometers.Engineering and Applied Sciences
10
Warne, Mark Anthony. "Theoretical studies in proton NMR spectroscopy". Thesis, University of Liverpool, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.321165.
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Smith, Timothy Andrew David. "Conformational analysis studies in NMR spectroscopy". Thesis, University of Liverpool, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.243220.
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Stott, Katherine Mary. "Pulsed field gradients in NMR spectroscopy". Thesis, University of Cambridge, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.627246.
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13
Amero, Carlos D. "Protein Function Study by NMR Spectroscopy". The Ohio State University, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=osu1205431343.
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14
Fauré, De la Barra Nicole Eloísa. "Understanding immobilised enzymes by NMR spectroscopy". Thesis, University of Glasgow, 2016. http://theses.gla.ac.uk/7319/.
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Enzyme immobilisation is the conversion of a soluble enzyme molecule into a solid particle form. This allows the recovery of the enzyme catalyst for its re-use and avoids protein contamination of the product streams. A better understanding of immobilised enzymes is necessary for their rational development. A more rational design can help enormously in the applicability of these systems in different areas, from biosensors to chemical industry. Immobilised enzymes are challenging systems to study and very little information is given by conventional biochemical analysis such as catalytic activity and amount of protein. Here, solid-state NMR has been applied as the main technique to study these systems and evaluate them more precisely. Various approaches are presented for a better understanding of immobilised enzymes, which is the aim of this thesis. Firstly, the requirements of a model system of study will be discussed. The selected systems will be comprehensibly characterised by a variety of techniques but mainly by solid-state NMR. The chosen system will essentially be the enzyme α-chymotrypsin covalently immobilised on two functionalised inorganic supports – epoxide silica and epoxide alumina – and an organic support – Eupergit®. The study of interactions of immobilised enzymes with other species is vital for understanding the macromolecular function and for predicting and engineering protein behaviour. The study of water, ions and inhibitors interacting with various immobilised enzyme systems is covered here. The interactions of water and sodium ions were studied by 17O and 23Na multiple-quantum techniques, respectively. Various pore sizes of the supports were studied for the immobilised enzyme in the presence of labelled water and sodium cations. Finally, interactions between two fluorinated inhibitors and the active site of the enzyme will be explored using 19F NMR, offering a unique approach to evaluate catalytic behaviour. These interactions will be explored by solution-state NMR firstly, then by solid-state NMR. NMR has the potential to give information about the state of the protein in the solid support, but the precise molecular interpretation is a difficult task.
15
Khajeh, Maryam. "Kinetic measurements using time-resolved NMR spectroscopy". Thesis, University of Manchester, 2010. https://www.research.manchester.ac.uk/portal/en/theses/kinetic-measurements-using-timeresolved-nmr-spectroscopy(aae85bb3-de19-450a-96ab-50e2dfd89da7).html.
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Many thousands of pounds are spent every year by pharmaceutical companies on understanding the mechanisms and kinetics of chemical reactions involved in drug discovery and production. NMR spectroscopy is often at the core of these studies as it is a powerful, non-destructive method for structure elucidation. As such investigations can be time-consuming and cost-inefficient, AstraZeneca, the project sponsor, is interested in more efficient methods for studying the kinetics of pharmaceutical reactions. In this work a number of different techniques have been devised, studied, and implemented to study the kinetics of chemical reactions by time-resolved NMR spectroscopy, in which every species in a reaction can be monitored simultaneously. These novel techniques allow the study of reactions which are difficult or impossible to study by conventional NMR methods (such as heterogeneous reactions), or which are complicated by having overlapping signals. It is possible to monitor the kinetics of a reaction very simply by acquiring a series of 1H spectra, and obtaining the integrals of the signals by least squares fitting. This technique has been used for kinetic studies of static and on-flow reactions. In the static systems the reaction mixture was placed in the normal NMR tube in the magnet, while in the flow system the reaction mixture was placed outside of the magnet, and the solution flowed through an NMR tube placed in the magnet. The novel flow system designed, constructed and tested here has been used for kinetic studies of illustrative homogeneous and heterogeneous reactions, and is suitable for use in a wide range of NMR instrumentation. Kinetic studies have also been carried out by acquiring a series of DOSY datasets, analysing the results using the multi-way method PARAFAC (PARAllel FACtor analysis). A series of DOSY datasets contains multivariate information on spectrum, time evolution and diffusion. Without providing any predetermined model, the data can be decomposed by PARAFAC to yield the spectrum, kinetics, and diffusion profiles for each of the components. It has also been shown that PARAFAC is remarkably robust to low signal-to-noise ratio data, significantly below the level at which conventional methods would fail.
16
Krishnan, Mangala Sunder. "Applications of irreducible spherical tensor operators to NMR and NQR spectroscopy". Thesis, McGill University, 1987. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=75771.
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The thesis extends the concept of Irreducible Spherical Tensor Operators to spin dynamics problems in Nuclear Magnetic and Quadrupole Resonance Spectroscopy. NQR and solid state NMR deal with spin systems which behave as effective single spins in many, pulsed experiments, or as multispin systems when the dipolar interactions among spins cannot be neglected. The thesis considers problems in both areas. New analytic results are derived in the thesis for pure NQR spectroscopy and for the effect of radiofrequency fields in the presence of electric quadrupolar interaction. Three-pulse experiments are proposed for a spin-5/2 system and quantitative calculations are done for the indirect detection of new observables. Attention is focussed on the usefulness of the full-spin density matrix in all these calculations. In addition the concept of multispin tensors is applied to a system of spin-1/2 nuclei with strong dipolar interactions. This leads to coupled differential equations for correlations among spins for which an iterative solution can be obtained. The solutions are discussed in relation to Free Induction Decay experiments available for $ sp{19}$F nuclei in CaF$ sb2$ crystal.
17
Säwén, Elin. "NMR spectroscopy and MD simulations of carbohydrates". Doctoral thesis, Stockholms universitet, Institutionen för organisk kemi, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-61569.
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Knowledge about the structure, conformation and dynamics of carbohydrates is important in our understanding of the way carbohydrates function in biological systems, for example in intermolecular signaling and recognition. This thesis is a summary of five papers studying these properties in carbohydrate-containing molecules with NMR spectroscopy and molecular dynamics simulations. In paper I, the ring-conformations of the six-membered rings of two carbaiduronic analogs were investigated. These carbasugars could potentially be used as hydrolytically stable mimics of iduronic acid in drugs. The study showed that the equilibrium is entirely shifted towards the 4C1 conformation. Paper II is an investigation of the conformational flexibility and dynamics of two (1→6)-linked disaccharides related to an oligosaccharide epitope expressed on malignant tumor cells. In paper III, the conformational space of the glycosidic linkage of an alfa-(1→2) linked mannose disaccharide present in N- and O-linked glycoproteins, was studied. A maximum entropy analysis using different priors as background information was used and four new Karplus equations for 3JC,C and 3JC,H coupling constants, related to the glycosidic linkage, were presented. Paper IV describes a structural elucidation of the exopolysaccharide (EPS) produced by Streptococcus thermophilus ST1, a major dairy starter used in yoghurt and cheese production. The EPS contains a hexasaccharide repeating unit of d-galactose and d-glucose residues, which is a new EPS structure of the S. thermophilus species. In paper V, the dynamics of three generations of glycodendrimers were investigated by NMR diffusion and 13C NMR relaxation studies. Three different correlations times were identified, one global correlation time describing the rotation of the dendrimer as a whole, one local correlation time describing the reorientation of the C-H vectors, and one correlation time describing the pulsation of a dendrimer branch.
18
Bergin, Paul Gerald. "Applications of tritium and tritium NMR spectroscopy". Thesis, University of Surrey, 2002. http://epubs.surrey.ac.uk/842709/.
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Tritium labelled compounds are widely used in the physical and life sciences. The preparation of such compounds is a very important area of chemistry. Although the methods are, on the whole, fairly simple and straightforward, there is still a need for improvement. The same applies as far as the analysis of the tritium distribution is concerned. High resolution 3H NMR spectroscopy of solutions is now a well established technique. However many compounds exist as solids which are either insoluble or sparingly soluble in organic solvents, consequently there is a need to develop high resolution 3H NMR spectroscopy of solids. The thesis therefore consists of four chapters. The first is a review dealing with the properties of tritium, the various labelling methods and tritium nuclear magnetic resonance spectroscopy. In the second chapter an account is given of the way in which complex metal tritides and tritiated methyl iodide, an important reagent which enables one to introduce three tritium atoms in a single step and therefore obtain products of very high specific activity, are prepared. In the third chapter an account is given of the synthesis and attempted tritiation of two potential 5-HT re-uptake inhibitors, prior to their use in biological studies. Whilst the synthesis of the two compounds N-[[[l-[(l-bromo-2-naphthalenyl)methyl]-4-piperidinyl]amino]carbonyl]-3-pyridinecarboxamide, and N-[[[l-[(l-bromo-6-fluoro-2-naphthalenyl)methyl] -4-piperidinyl]amino]carbonyl]-3-pyridinecarboxamide, was successful the tritiation procedure led to unforseen difficulties. Finally in the fourth chapter solid state tritium NMR spectroscopy, using a magic angle accessory, was developed and used in the analysis of several tritiated compounds.
19
Hu, Song 1969. "Thrombin exosite interactions studied by NMR spectroscopy". Thesis, McGill University, 1996. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=23897.
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Fibrinogen, thrombin receptor and heparin cofactor II are three major thrombin substrates recognized specifically through its exosite, a regulatory binding site. Based on the native protein sequences, four peptides were selected to study the specificity of exosite interactions on structural basis using transferred NOE methods. The binding sequences of all the peptides are identified and possible thrombin binding sites of thrombin receptor and heparin cofactor II peptides are speculated by comparing with known hirudin-thrombin complex structures. A new binding mode may exist in thrombin-fibrinogen contacts according to its exosite binding sequence and interaction patterns. In terms of the binding sequence, it suggested that the most important factor in thrombin exosite specific binding is the hydrophobic residues position rather than the analogous sequence.
20
Varma, S. C. "Polymer end-group studies using NMR spectroscopy". Thesis, Lancaster University, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.374665.
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21
Zagdoun, Alexandre. "Dynamic Nuclear Polarisation Surface Enhanced NMR Spectroscopy". Phd thesis, Ecole normale supérieure de lyon - ENS LYON, 2014. http://tel.archives-ouvertes.fr/tel-01065554.
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Since its discovery in the 1950's, DNP has been a topic of significant interest in magnetic resonance. DNP is the transfer of polarization between single electrons and nuclei, driven by micro-wave irradiation. Since its renaissance at high field in the 90's, due to the introduction of gyrotrons as high-power, high-frequency microwave sources most application of this technique have been samples of biological interest in frozen solution. The long standing interest of our group in the characterization of surface species such as supported catalysts on silica lead us to apply this technique to the study of surfaces. The goal of this thesis is the development of this method, dubbed DNP Surface Enhanced NMR Spectroscopy. To that end, we first introduce new polarizing agents, soluble in organic solvents. The influence of the electron relaxation times on the DNP enhancements is demonstrated and efficient tailored polarizing agents are introduced. The optimization of the sample preparation to obtain optimal sensitivity is also discussed, as well as the interaction between the radical and the surface. These developments made it possible to apply the technique to many functionalized materials, with some examples developed in this manuscript. Finally, the issue of DNP on polarization conductors is discussed, and we show how microcrystals can be efficiently polarized using DNP.
22
Eyles, Stephen J. "Studies of protein folding by NMR spectroscopy". Thesis, University of Oxford, 1995. http://ora.ox.ac.uk/objects/uuid:06b8fb16-790c-4b72-80d0-8317920655fe.
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This thesis describes an investigation of the folding and stability of a series of derivatives of the proteins lysozyme and α-lactalbumin which lack one or more of their four native disulphide bridges. Removal of the disulphide bridge which links the N- and C-termini from hen lysozyme results in a three-disulphide derivative (CM6,127-lysozyme). This has a profound effect on its stability against thermal denaturation, the Tm for unfolding being reduced by 25°C at pH 3.8. Calorimetric measurements performed on this three-disulphide derivative indicate that this reduction in stability may be attributed entirely to an increase in the entropy difference between the native and denatured states. Kinetic refolding studies of CM6,127-lysozyme using stopped flow optical methods and hydrogen exchange pulse labelling in conjunction with NMR and electrospray ionisation mass spectrometry (ESI-MS) suggest that this reduced stability manifests itself primarily in the α-domain of the protein. A transient intermediate populated during refolding of the unmodified protein can no longer be detected during folding of the derivative resulting in highly cooperative folding under the conditions investigated. The structure and stability of a three- and two-disulphide derivative of the homologous protein, α-lactalbumin have been investigated by NMR spectroscopy. The three-disulphide species, like its lysozyme counterpart, can adopt native structure but this is much more unstable than the intact protein. Removal of a second disulphide bridge, however, destabilises α-lactalbumin to the extent that the native state is no longer formed. Instead, in the presence of Ca2+ and high concentrations of salt, a partially structured state is induced which has some elements of tertiary structure present. Novel techniques of ESI-MS have been developed to study protein folding and stability using hydrogen exchange techniques. Applications to the investigation of cooperativity in protein folding, stability in native, partially folded and unfolded states, and the interactions of a partially folded protein with the chaperone GroEL are described.
23
Grieves, R. A. "Multinuclear NMR spectroscopy of transition metal complexes". Thesis, University of Bradford, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.372167.
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Edgar, Mark. "Studies in proton and flourine NMR spectroscopy". Thesis, University of Liverpool, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.240501.
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Cantalapiedra, Nuria Aboitiz. "Intramolecular hydrogen-bonding studies by NMR spectroscopy". Thesis, University of Liverpool, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.366715.
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Kraft, Robert A. (Robert Arthur) 1970. "In vivo two-dimensional NMR correlation spectroscopy". Thesis, Massachusetts Institute of Technology, 1999. http://hdl.handle.net/1721.1/85271.
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Gao, Chun. "19F DOSY Diffusion NMR Spectroscopy of Fluoropolymers". University of Akron / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=akron1447069266.
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Rogerson, Alexandria. "New techniques in diffusion-ordered NMR spectroscopy". Thesis, University of Manchester, 2013. https://www.research.manchester.ac.uk/portal/en/theses/new-techniques-in-diffusionordered-nmr-spectroscopy(aa3eaee0-984b-4434-b460-8c3118a7c3b2).html.
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The analysis of mixtures is a subject that spans several different analytical techniques. In NMR, a powerful technique for this analysis is Diffusion-Ordered NMR Spectroscopy (DOSY), in which signals from different chemical species can be distinguished by their different diffusion coefficients. DOSY NMR allows an analysis of mixture components and their interactions in a non-invasive way and is proving to be an accurate and time effective method for looking at mixtures.An in-depth analysis of DOSY NMR is presented using the commercial mixture “monoacetin”. The chemically cognate species in this mixture produce complex and overlapping multiplet signals in 1H NMR that are difficult to assign and interpret. A previous analysis of this mixture used 1H NMR together with Liquid Chromatography (LC) and Gas Chromatography (GC) to identify the components present, but failed to provide complete assignments of all the signals. Here, the possibility of using DOSY as an alternative to hyphenated techniques is examined, and it is shown that a full analysis of the spectrum of “monoacetin” is possible with careful selection of experimental parameters and processing techniques, without recourse to chromatography. DOSY NMR can be ineffective when signals overlap and/or diffusion coefficients are similar. Many methods have been proposed to overcome these problems, and some of these are presented here. In order to increase resolving power, it is possible to gather further information about a mixture and incorporate this into diffusion experiments as another dimension. This creates a 3D dataset that can be analysed using a multiway method, such as PARAFAC, to extract the component spectra. This method is explored for the mixture “monoacetin” that has been partially separated by high-performance liquid chromatography. Resolution of two out of four components was achieved from poor HPLC separation; the decomposition obtained the component spectra, diffusional decay and HPLC elution profile for these components. Improved HPLC separation should result in further resolution.Diffusion coefficients of different mixture species can be manipulated by changing the matrix in which they diffuse: Matrix-Assisted DOSY (MAD). Previous techniques have involved either improving resolution in the diffusion domain or aiming to improve resolution in chemical shift. A method is presented here that simultaneously addresses both problems in a chemically-selective way, using lanthanide shift reagents. The chemically-selective binding of the LSR to mixture components can both enhance chemical shift dispersion and increase diffusion resolution in DOSY. This neatly deals with the two main drawbacks of the DOSY experiment, and is demonstrated using a mixture of an alkane, alcohol and aldehyde. The manipulation of a molecule’s electrostatic charge through pH control has been investigated, where small ions with a high charge density would be highly solvated, resulting in a change in D. The effect, however, was not measurable and so the indirect effect of pH on the interaction of charged species with the cationic micelle CTAB is presented, where an increase in resolution between of mixture of aspirin and salicylic acid is achieved.Although DOSY NMR is a powerful tool for mixture analysis, in recent years it has been used for studying molecular interactions. An example of this is presented here where species aggregate under specific conditions, a process identified by DOSY NMR.
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Inglis, Benjamin Alastair. "In vivo NMR spectroscopy of the brain". Thesis, Queen Mary, University of London, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.644797.
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Miletti, Teresa. "Enzyme flexibility studied by solution NMR spectroscopy". Thesis, McGill University, 2013. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=119414.
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The important connection between dynamics, structure and function of enzymes still remains unclear and is, hence, an interesting relationship to investigate. In this thesis, the enzymes NADH oxidase (NOX) from Thermus thermophilus and mycobacterium tuberculosis (Mtb) protein tyrosine phosphatase B (PtpB) were chosen as systems to study the influence of solution conditions on protein structure and flexibility in relation to their catalytic activity. Nuclear magnetic resonance (NMR) and isothermal titration calorimetry (ITC) techniques were used in the study of NOX. NMR and differential scanning fluorimetry (DSF) were utilized to assess the sample stability of PtpB under various buffer conditions.NOX is a 54 kDa homodimeric enzyme with many potential biotechnology applications. It accepts cofactors flavin mononucleotide (FMN) or flavin adenine dinucleotide (FAD). It has high thermal stability and its activity increases with the addition of low concentrations of urea. Using enzymes in vitro provides us a lot of freedom to control its environment, which is useful to look at changes occurring under different conditions. Thus, NMR allowed us to investigate these interesting characteristics on NOX dynamics and structure. When Mtb infects host cells it secrets among others, PtpB, to disrupt signalling pathways and blunts immune responses. PtpB contains a two-helix lid that completely buries the active site and it is proposed that it has evolved as a novel mean of protection against host chemical defences and affords substrate access. An investigation of conformational dynamics of the lid domain of PtpB using NMR would elucidate a relation between conformation and function of Ptpb, which to date, is still unknown and would contribute to the development of inhibitors as potential drugs. In order to do this, it is essential to obtain a stable sample that will give optimal quality NMR spectra. NMR and DSF were used to optimize PtpB NMR sample conditions and spectral quality. We employed a suite of novel 15N NMR relaxation experiments to estimate the extent of broadening due to microsecond-timescale motions and to measure exchange-free transverse relaxation rates on a per-residue basis of NOX. These measurements allowed us to identify several residues involved in dynamical processes. Moreover, order parameters, S2, determined from standard 15N T1, T2 and {1H}-15N steady NOE experiments, allowed the identification of additional residues characterized by motions on nanosecond-picosecond time scales. We then investigated the effects of temperature, urea addition, cofactor and NAD+ product binding to NOX using NMR and ITC. For each condition studied, chemical shift displacement of NMR peaks is significant relative to all other peaks only for a reoccurring small subset of residues. This cluster of residues is located around the active site of the enzyme and thus, suggests evidence of a relationship between concerted conformational rearrangement of NOX structure and NOX catalytic activity. An increase in NMR spectral quality and a NMR sample of PtpB with increased thermal stability, higher yields and reduced aggregation was obtained for further NMR dynamic experiments. This was achieved by optimizing the sample conditions by performing several NMR titrations and DSF experiments. Assessing the thermal stability of enzymes with different additives using DSF could be easily introduced during the elaboration of protein purification protocols as a routine method to optimize NMR sample conditions for NMR studies.Le lien important entre la dynamique, la structure et la fonction des enzymes n'est pas encore bien défini et est donc une relation intéressante à étudier. Dans cette thèse, les enzymes NADH oxydase (NOX) de Thermus thermophilus et mycobacterium tuberculosis protéine tyrosine phosphatase B (PtpB) sont les systèmes choisis pour étudier l'influence des conditions de solution sur la structure et la flexibilité des protéines par rapport à leur activité catalytique. Les techniques de résonance magnétique nucléaire (RMN) et de calorimétrie de titration isothermique (ITC) ont été utilisées dans l'étude de NOX. La RMN et la fluorimétrie différentielle à balayage (DSF) ont été utilisées pour évaluer la stabilité de l'échantillon de PtpB dans diverses conditions de tampons. NOX est une enzyme homodimérique avec de nombreuses applications biotechnologiques potentielles. NOX accepte les cofacteurs flavine mononucléotide (FMN) ou flavine adénine dinucléotide (FAD). L'enzyme a une stabilité thermique élevée et son activité augmente avec l'addition de faibles concentrations d'urée. Utiliser des enzymes in vitro donne beaucoup de liberté pour contrôler leur environnement, utile pour examiner les changements qui se produisent dans différentes conditions. Ainsi, RMN nous a permis d'étudier ces caractéristiques intéressantes sur la dynamique et la structure de NOX. Lorsque Mtb infecte les cellules, il secrète PtpB qui perturbe les voies de signalisation et affaibli les réponses immunitaires. PtpB contient un couvercle de deux hélices qui enterre complètement le site actif et il est proposé qu'il ait évolué ainsi en protection contre les défenses chimiques et permet un accès au substrat. Une étude de la dynamique du domaine du couvercle de PtpB utilisant la RMN éluciderait la relation entre la conformation et la fonction de PTPB et contribuerait au développement d'inhibiteurs en tant que médicaments potentiels. Pour ceci, il est essentiel d'obtenir un échantillon stable qui donnera des spectres RMN de qualité optimale. RMN et DSF ont été utilisés pour optimiser les conditions d'échantillonnage de PtpB pour la RMN et la qualité spectrale. Nous avons utilisé une suite de nouvelles expériences de relaxation de 15N par RMN pour estimer l'ampleur de l'élargissement des signaux en raison de mouvements à l'échelle de temps des microsecondes et de mesurer les taux de relaxation transversale sans échange pour chaque résidu de NOX. Ces mesures nous ont permis d'identifier plusieurs résidus impliqués dans les processus dynamiques. De plus, les paramètres d'ordre, S2, déterminées à partir des expériences standards de T1, T2 et NOE, ont permis d'identifier des résidus additionnels caractérisés par des mouvements sur des échelles de temps de nanosecondes à picosecondes. Nous avons ensuite étudié les effets de la température, urée, la liaison de cofacteur et du produit à NOX en utilisant la RMN et le ITC. Pour chaque condition étudiée, la variation de déplacement chimique des signaux RMN n'est significative par rapport à tous les autres signaux que pour un petit sous-ensemble récurrent de résidus. Cet amas de résidus est situé autour du site actif de l'enzyme et ainsi, suggère preuve d'une relation entre un réarrangement conformationnel concertée de la structure de NOX et de son activité catalytique. Une augmentation de la qualité spectrale de RMN et un échantillon de PtpB pour la RMN avec une meilleure stabilité thermique, des rendements plus élevés et une agrégation réduite ont été obtenus pour de futures expériences dynamiques par RMN. Ceci a été réalisé en optimisant les conditions de l'échantillon en effectuant plusieurs titrages par RMN et des expériences de DSF. L'évaluation de la stabilité thermique des enzymes avec différents additifs à l'aide de DSF pourrait facilement être introduit lors de l'élaboration de protocoles de purification de protéines comme une méthode routinière pour optimiser les conditions d'échantillons pour les études par RMN.
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Le, Guennec Adrien. "Fast 2D NMR spectroscopy for complex mixtures". Palaiseau, Ecole polytechnique, 2015. https://theses.hal.science/tel-01191697/document.
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La métabolomique est un domaine récent dont le but est d’analyser l'ensemble des molécules participant aux réactions chimiques d'un organisme. L'utilisation de la Résonance Magnétique Nucléaire (RMN) pour la métabolomique est en plein essor grâce à une méthodologie basée sur des spectres à une dimension (1D) du proton. Cependant, les spectres 1D de mélanges complexes, comme les extraits ou fluides biologiques, présentent un recouvrement important des signaux RMN, ce qui peut poser problème pour l'identification et la quantification des molécules d’intérêt. L'utilisation d’expériences RMN à deux dimensions (2D) permet en principe de limiter les risques de recouvrement. Cependant, la durée des expériences 2D est souvent prohibitive pour la métabolomique. Plusieurs approches existent afin de réduire la durée des expériences RMN 2D, mais elles n'ont pas à ce jour été évaluées dans le cadre de la métabolomique. Au cours de cette thèse, nous avons démontré le potentiel de la RMN 2D rapide pour la métabolomique et optimisé ses performances. Deux approches RMN 2D rapides ont été testées : la RMN ultrarapide et l'échantillonnage non-uniforme. Par une étude avec des échantillons synthétiques, nous avons pu démontrer, dans un premier temps, l'intérêt de la RMN 2D par rapport à la RMN 1D pour la métabolomique, puis l'utilisation des approches 2D rapides pour obtenir la même information que la RMN 2D conventionnelle avec un temps d'acquisition réduit. Nous avons ensuite cherché à optimiser l'utilisation des approches 2D rapides pour l'analyse des mélanges complexes. Dans un premier temps, une nouvelle séquence a été développée en RMN 2D ultrarapide du proton, afin de supprimer les pics diagonaux, qui peuvent recouvrir des pics de corrélations et donc réduire l'information disponible sur les spectres. Ensuite, l'échantillonnage non-uniforme a été utilisé afin d'augmenter jusqu'à 32 fois la résolution dans la dimension indirecte sans perte de sensibilité ou de répétabilité ou d'augmentation de la durée d'expérience. Enfin, des essais ont été effectués afin d’automatiser la détermination des constantes de relaxation directement dans les mélanges complexes. Ces différents outils ouvrent des perspectives d’application prometteuses pour l’analyse métabolomique à haut débit d’échantillons biologiquesMetabolomics is a recent area of research, which aims at analyzing the entirety of molecules involved in chemical reactions in an organism. Nuclear Magnetic Resonance (NMR) is widely used in metabolomics nowadays thanks to a methodology based on one-dimensional (1D) NMR. However, 1D spectra of complex mixtures, like biological extracts or fluids, are characterized by important overlap between peaks, which can be detrimental to the identification and quantification of molecules of interest. Two-dimensional (2D) NMR can be used to reduce the risk of overlap. However, the duration of 2D experiments is often prohibitive for metabolomics studies. Several approaches exist to reduce the duration of 2D experiments, but they have not been evaluated so far for metabolomics. In this thesis, we have shown the usefulness of fast 2D NMR for metabolomics and optimized its performances. Two fast 2D NMR approaches have been evaluated, ultrafast 2D NMR and non-uniform sampling. In a study with synthetic samples, we first demonstrated the usefulness of 2D NMR compared to 1D NMR, then we showed that the experimental time of 2D spectra could be reduced with fast 2D NMR approaches without loss of information. Then we optimized the use of fast 2D NMR for complex mixture analysis. First, we developed a new pulse sequence with ultrafast 2D NMR of proton, in order to suppress the diagonal peaks, which can overlap with correlation peaks and therefore reduce the information content of 2D spectra. Then non-uniform sampling was used to increase up to 32 times the resolution in the indirect dimension without increasing the experimental time and without loss of sensitivity or repeatability. Finally, we worked on automating the determination of relaxation constants in complex mixture. These tools open promising perspectives for high-throughput metabolomics of complex biological samples
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Davis, Adrian Lawrence. "Restriction of coherence transfer in NMR experiments". Thesis, University of Cambridge, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.239203.
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Bonet, i. Figueredo Roman. "Structural studies on FF domains by NMR spectroscopy". Doctoral thesis, Universitat Autònoma de Barcelona, 2009. http://hdl.handle.net/10803/3609.
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El present treball s'ha realitzat en el marc del Programa de Biologia Estructural i Computacional de l'IRB Barcelona, en el grup de RMN de proteïnes, sota la direcció de la Dra María J. Macías. L'interès del grup d'investigació se centra en la determinació estructural de dominis de proteïna, en l'estudi d'interaccions i en entendre els mecanismes per a la seva regulació. Concretament, aquest treball està enfocat en l'estudi estructural de dominis FF.En el nostre grup es va començar a estudiar els dominis FF a partir de l'observació que aquests dominis es troben sovint en proteïnes que també contenen WW, un petit domini d'interacció proteïna-proteïna que ha estat i continua sent la línia d'investigació principal del grup, i del qual s'han realitzat nombrosos i detallats estudis.
En canvi, el dominis FF han estat identificats fa poc temps i la informació estructural i funcional de la qual es disposa és, a dia d'avui, escassa. En part, el pocs estudis realitzats amb aquests dominis pot ser conseqüència de que només els trobem en un conjunt reduït de proteïnes. De fet, la seva presència es limita a tres famílies de proteïnes: els factors d'splicing FBP11, Prp40 i URN1, el factor de transcripció CA150 i una família de proteïnes reguladores de RhoGTPases, les p190 RhoGAPs.
Al meu grup, l'estudi amb dominis FF es va iniciar amb la resolució de l'estructura tridimensional del primer FF de la proteïna Prp40 de llevat, que va representar la segona estructura resolta per a un domini FF. En aquest treball l'objectiu ha estat aprofundir en el coneixement dels dominis FF, bàsicament des d'un punt de vista estructural utilitzant com a tècnica principal la resonànica magnètica nuclear (RMN).
Aquesta tesi doctoral s'ha dividit en tres parts i en cada una d'elles s'ha treballat amb els dominis FF de les tres famílies de proteïnes esmentades anteriorment. L'enfoc també ha estat lleugerament diferent a cada part. Així, en el primer capítol, centrat en els dominis FF presents als factors d'splicing URN1 i Prp40, el gruix de la feina va ser l'obtenció de noves estructures tridimensionals per RMN d'aquests dominis. En canvi, en el segon capítol ens vam centrar en l'estudi de la interacció dels dominis FF de CA150 amb el seu primer lligand descrit, un motiu doble fosforilat del domini C-terminal de la RNA-polimerasa II (fosfo-CTD). Finalment, en la tercera part l'interès es va dirigir a l'estudi de la regulació de l'associació dels dominis FF de p190-A RhoGAP amb el factor de transcripció TFII-I, per mitjà d'una fosforilació sobre el primer FF de p190-A RhoGAP.
The present work has been done in the protein NMR group from the Structural and Computational Biology at the IRB Barcelona, under the direction of Dr. Maria J. Macias.
The group's main interest is the structural determination of protein domains, in the study of their interactions and in the understanding of the mechanisms for their regulation. In particular, this work is focused in the structural study of FF domains.
In our group, the study of FF domains began from the observation that these domains are often found in proteins that also contain WW domains, a small protein-protein interaction domain that has been, and continues to be the central research line of the group and that has been object of numerous and detailed studies.
Conversely, FF domains have been recently identified and the structural and functional information available on them is, to date, limited. One of the reasons of the few studies reported for these domains could be consequence of their reduced presence in proteins. In fact, FF domains are only present in three protein families: the splicing factors FBP11, Prp40 and URN1, the transcription factor CA150 and a family of RhoGTPase regulators, the p190 RhoGAPs.
In our group, the work with FF domains started with the solution of the three-dimensional structure of the first FF domain from yeast Prp40, which just represented the second solved structure for an FF domain. In the present work the aim has been to gain insight into FF domain knowledge, basically from a structural point of view, using nuclear magnetic resonance (NMR) as the principal methodology for the structural studies.
This thesis has been divided in three parts, and in each of them we have work with FF domains from the different families mentioned above. The subject of study has been also slightly different in each part. In the first chapter, focused in FF domains present in Prp40 and URN1 splicing factors, the principal work consisted in the obtaining of novel three-dimensional structures for these domains by NMR. In contrast, in the second chapter the main interest was the study of the interaction of CA150 FF domains with their first described ligand, a doubly phosphorylated motif of the RNA polymerase II C-terminal domain (phospho-CTD). Finally, in the last part our efforts were focused in the study of the regulation of p190-A RhoGAP FF domains association with the general transcription factor TFII-I through phosphorylation on the first FF domain of p190-A RhoGAP.
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Frise, Anton. "Nano-segregated soft materials observed by NMR spectroscopy". Doctoral thesis, KTH, Fysikalisk kemi, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-30337.
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This thesis is about using nuclear magnetic resonance (NMR) spectroscopy for studying soft materials. Soft materials may be encountered everyday by most readers of this thesis, for example when taking a shower or watching TV. The usefulness of these materials originates from them being soft yet, at the same time, having some kind of a structure. The characteristic length scale of those structures is often on the order of nanometers (10-9 m) and the structure can respond to various external stimuli such as temperature, electric and magnetic fields, or the presence of interfaces. NMR spectroscopy excels when studying soft materials because it is a non-invasive technique with a large spectral resolution. Moreover, different NMR methods allow us to study local molecular dynamics or longer-range translational diffusion. Understanding those latter aspects is very important for the development of dynamic and responsive materials. Papers I-III present our work on assessing molecular adsorption on interfaces in colloidal dispersions. Here, carbon nanotubes (CNTs) or silica particles were the colloidal substrates to which proteins, polymers or surfactants adsorbed. Papers IV-VI concern ionic mobility in liquid crystals (LCs). The influence of material structure on, for example, the anisotropy of diffusion or on the association/dissociation of ions was studied in several LC phases.QC 20110225
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Koskela, H. (Harri). "Some aspects of polarisation transfer in NMR spectroscopy". Doctoral thesis, University of Oulu, 2005. http://urn.fi/urn:isbn:9514277988.
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Abstract
Modern NMR methods in liquids are based on the transfer of polarisation from nucleus to nucleus to generate multidimensional heteronuclear correlation spectra. The factors that influence the efficiency of heteronuclear polarisation transfer in multi-pulse experiments, and in that way the quality of spectra are the subject of this thesis. The flow of coherence through pulse sequences can be designed and analysed with the aid of product operator calculations. Results of the study include improvements to quantitative two-dimensional shift-correlated experiments, and demonstration of the benefits of closely spaced 180° pulse trains in polarisation transfer steps in long-range correlation experiments and isotope editing filters.
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Talagala, Sardha Lalith. "Aspects of NMR imaging and in vivo spectroscopy". Thesis, University of British Columbia, 1986. http://hdl.handle.net/2429/27550.
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The work described in this thesis deals mainly with aspects related to two- and three-dimensional NMR imaging.
A detailed discussion on frequency-selective excitation using amplitude modulated rf pulses in relation to slice selection in NMR imaging has been presented. This includes the analysis and implementation
of the method as well as illustrative experimental results.
Several radiofrequency probe designs suitable for high field NMR imaging have been experimentally evaluated and their modification and construction are also described. The comparative results obtained indicate the merits and demerits of different designs and provide necessary guidelines for selecting the most suitable design depending on the application.
Practical aspects of two- and three-dimensional imaging have been discussed and NMR images of several intact systems have been presented.
Experimental methods which enable slice selection in the presence of chemically shifted species and two-dimensional chemical shift resolved imaging have "been described and illustrated using phantoms. The use of three-dimensional chemical shift resolved imaging as a potential method to map the pH and temperature distribution within an object has also been demonstrated.
A preliminary investigation of the application of ³¹P NMR spectroscopy
to study the biochemical transformations of the rat kidney during periods of ischemia and reperfusion has been presented.Science, Faculty of
Chemistry, Department of
Graduate
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Khan, Amjad. "NMR spectroscopy studies of enzyme function and inhibition". Thesis, University of Oxford, 2016. https://ora.ox.ac.uk/objects/uuid:698d69c7-d4f1-4bc7-bf0b-3b9e7fb3a4fe.
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The work described in this Thesis focuses on the application of NMR spectroscopy methods in understanding the function and inhibition of two protein systems; these are ?-butyrobetaine hydroxylase (BBOX) and the bacterial potassium ion efflux (Kef) system. BBOX belongs to the super family of enzymes called the 2- oxoglutarate (2OG) and FeII dependent oxygenase and is involved in the biosynthesis of L-carnitine in humans and other prokaryotes. BBOX is a current drug target for the treatment of myocardial infarction. Kef is a ligandgated system that protects bacteria from toxic electrophilic species. Kef is inhibited by the binding of cytoplasmic glutathione (GSH) to KTN (K+ transport and nucleotide) binding domains and activated by glutathione-S-conjugates (GS-X). Since bacterial Kef activation during electrophilic exposure is a critical determinant of their survival, perturbation of Kef activity is potentially a novel target for the development of antibiotic drugs. 1H NMR direct ligand-observation was employed to study the binding interaction of the natural substrate ?- butyrobetaine (GBB) and co-substrate 2OG with BBOX. A 1H NMR-based dual-reporter ligand displacement method was developed to assess the nature of inhibitor binding to BBOX i.e to determine whether an inhibitor competes with GBB or 2OG or both. The method was exemplified with a set of isoquinoline-based inhibitors; the results reveal 'cystallographically unexpected' structure-activity relationship with some inhibitors competing 2OG only and some competing both 2OG and GBB. Using 1H NMR spectroscopy, a simple and efficient BBOX inhibition assay was developed for inhibitor IC50 measurement. Similarly, 1H NMR-based assays were applied to demonstrate that the cation-p interaction between the substrates and aromatic cage residues of BBOX play a critical role in BBOX substrate recognition. 1H NMR spectroscopy was applied to show that in the absence of a 2OG oxygenase, ascorbate in the assay mixture is slowly degraded by the dissolved oxygen to yield H2O2 which simultaneously leads to 2OG breakdown into succinate. It is proposed that in the assays of 2OG oxygenases, the apparent increase in the level of "uncoupled" 2OG turnover with ascorbate over time could possibly be due to the artifacts of the ascorbate induced-2OG breakdown instead of being due to enzyme catalysis. Other reducing agents were also found to oxidise identically by the dissolved oxygen as ascorbate in the mixture and result in 2OG breakdown. In the Kef system, 1H NMR direct ligand-observation was applied to investigate the influence of each functional group of the Kef activating ligand glutathione-S-N-tertiary butylsuccinimide on its binding interaction (KD 0.4 μM) with Kef-QCTD (Q-linker carboxy terminal domain; a KTN domain) from Shewanella denitrificans (sd) with the aim of developing novel non-peptidic ligands (antibacterial agents) of Kef. In addition, 19F NMR was employed to develop an efficient ligand-observed binding assay for Kef that was used for ligand screening as well as measuring their binding dissociation constant value from a single NMR spectrum. Finally, a 1H NMR technique was applied to confirm that the electron density found in the nucleotide binding pocket in the crystal structure of apo-sdKef-QCTD is unambiguously an AMP molecule that is naturally bound to the protein and has a role in stabilising the dimeric form of KTN domains (Kef proteins).
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Feng, Xiaolong. "Estimating molecular conformations by solid-state NMR spectroscopy /". Stockholm : Eigenverl, 1998. http://www.gbv.de/dms/goettingen/265942721.pdf.
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Glaubitz, Clemens. "Magic angle sample spinning NMR spectroscopy on biomembranes". Thesis, University of Oxford, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.267922.
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Dowell, Nicholas G. "Further developments in high-resolution quadrupolar NMR spectroscopy". Thesis, University of Exeter, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.407274.
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Lesperance, Leann M. (Leann Marie). "Compositional studies of cartilage matrix using NMR spectroscopy". Thesis, Massachusetts Institute of Technology, 1993. http://hdl.handle.net/1721.1/17331.
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Thesis (Ph. D.)--Massachusetts Institute of Technology, Whitaker College of Health Sciences and Technology, 1993.Includes bibliographical references (leaves 142-150).
by Leann Marie Lesperance.
Ph.D.
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Orr, Robin Macnab. "Measuring anisotropic interactions using solid-state NMR spectroscopy". Thesis, University of Cambridge, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.612898.
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Odedra, Smita. "Some novel developments in high-resolution NMR spectroscopy". Thesis, University of Glasgow, 2014. http://theses.gla.ac.uk/5772/.
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The radiofrequency (rf) pulses used in NMR are subject to a number of imperfections, such as those resulting from the inhomogeneity of the rf field or an offset of the transmitter frequency from exact resonance. In spin-echo experiments, these imperfections yield spectra with reduced signal intensity and distorted phase. Composite pulses, which have tailored bandwidth properties with respect to experimental frequency parameters such as the rf field strength or resonance offset, offer a route to improving the amplitude of the spin-echo signal. However, the symmetry of the pulse sequence must be carefully considered to prevent the introduction of phase errors into the spin-echo signal. Here, composite pulses will be studied as a means to improving one of the most common techniques for 1H background suppression in MAS NMR, the ”Depth” sequence. Novel composite 180° pulses will be presented for this application and verified experimentally. The composite pulse Depth experiment yields spectra with improved amplitude of the 1H signals of interest, while successfully maintaining good suppression of background signals. Novel families of dual-compensated 180° composite pulses for I = 1/2 will also be designed for use in NMR spin-echo experiments. These pulses are capable of simultaneously compensating for resonance offset and rf inhomogeneity problems. Crucially, unlike many composite pulses that have been presented before, these new pulses have the correct symmetry properties to form a spin echo without phase distortion. Composite pulses have found wide usage in solution-state NMR, and although in principle the same pulses can be applied in solid-state NMR experiments, complications can arise under magic angle spinning (MAS). The effects of MAS on composite pulse performance will be explored both through computer simulations and 31P experiments. Finally, on a different theme, we will investigate spin-locking of half-integer quadrupolar nuclei in solids. Spin-locking is an important feature of many NMR experiments, yet the complex behaviour observed for quadrupolar nuclei is not fully understood. Using the theoretical model introduced by Ashbrook and Wimperis, we will investigate the far off-resonance case of spinlocking for I = 3/2 and I = 5/2 nuclei.
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Zhu, Xu Carleton University Dissertation Chemistry. "129Xe NMR spectroscopy of xenon in coal micropores". Ottawa, 1994.
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Asami, Sam. "Method development for biomolecular solid-state NMR spectroscopy". Doctoral thesis, Humboldt-Universität zu Berlin, Mathematisch-Naturwissenschaftliche Fakultät I, 2014. http://dx.doi.org/10.18452/17044.
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Im Rahmen der vorliegenden Arbeit, wird ein neuartiges Markierungsschema für die Festkörper-NMR-Spektroskopie vorgestellt, das sogenannte Reduced Adjoining Protonation (RAP) Schema, welches die Protonendetektion sämtlicher Aliphaten erlaubt. Hochaufgelöste, 1H-detektierte 1H,13C Korrelationsspektren wurden erhalten. Des Weiteren wurde der Vorteil von hohen MAS-Frequenzen untersucht. 1H- und 13C-detektierte 3D Zuordnungsexperimente wurden implementiert, welche uns die Zuordnung von 90% aller aliphatischen Resonanzen von alpha-Spektrin SH3 erlaubten. Da die chemische Verschiebung abhängt vom Strukturmotiv, kann sie verwendet werden, um Sekundärstruktur-Informationen abzuleiten. Darüber hinaus wurde ein 1H-detektiertes H(H)CH 3D Experiment entwickelt, um weitreichende 1H,1H Kontakte zu ermitteln, welche für die Bestimmung der Tertiärstruktur genutzt werden können. Um artefaktfreie Relaxationsdaten zu erhalten, wurde das RAP-Markierungsschema modifiziert, um 1H- und 13C-verdünnte Proben zu erhalten, in denen Spindiffusion unterdrückt ist. Für die Untersuchung von Sub-Mikrosekunden-Dynamik werden Experimente vorgestellt zur Bestimmung von 13C T1 Relaxationszeiten und 1H,13C dipolaren Kopplungstensoren für Rückgrat- und Seitenketten-Resonanzen. Des weiteren zeigen wir, dass das RAP-Markierungsschema auf nicht-kristalline Systeme, wie Amyloidfibrillen des Abeta1-40 Peptids der Alzheimer-Krankheit, angewendet werden kann. Unter Verwendung von 1H-Detektion, erhielten wir hochaufgelöste 1H,13C Korrelationsspektren. Schließlich wurde der Perdeuterierungsansatz auf den L7Ae-box C/D Protein-RNA Komplex aus P. furiosus angewendet. Wir erhielten hochaufgelöste, 1H-detektierte 1H,15N, sowie 13C,13C Korrelationsspektren des Protein-RNA Komplexes. Weiterhin haben wir eine Methode zur Bestimmung genauer Abstands- und Winkelinformationen für die Protein-RNA Schnittstelle etabliert und schlagen Ansätze vor, für die Zuordnung der chemischen Verschiebungen von RNA-Resonanzen.In this thesis, a novel labeling scheme for solid-state NMR spectroscopy, the Reduced Adjoining Protonation (RAP) scheme, is introduced, which allows proton detection of all aliphatic sites, as shown for the microcrystalline SH3 domain of alpha-spectrin. These samples yield high-resolution, 1H-detected 1H,13C correlation spectra. In addition, the benefit of high MAS frequencies was investigated. 1H- and 13C-detected 3D assignment experiments are implemented, which allowed us to assign 90% of all aliphatic resonances of alpha-spectrin SH3. As the chemical shift is dependent on the structural motif, it can be employed to derive secondary structure information. Furthermore, a 1H-detected H(H)CH 3D experiment is introduced, to obtain long-range 1H,1H contacts, which can be used for the determination of the tertiary structure. To obtain artifact-free relaxation data, the RAP labeling scheme was modified to obtain sparsely proton labeled, 13C dilute samples, in which spin diffusion is suppressed. To probe sub-microsecond dynamics, we report experiments to determine 13C T1 relaxation times and 1H,13C dipolar coupling tensors for backbone and side chain resonances, respectively. Furthermore, we show, that the RAP labeling scheme can be applied to non-crystalline systems, such as amyloid fibrils of the Alzheimer’s disease peptide Abeta1-40. Using 1H-detection, we obtained high-resolution 1H,13C correlation spectra. Finally, we applied the perdeuteration approach to the L7Ae-box C/D protein-RNA complex from P. furiosus. We obtained high-resolution, 1H-detected 1H,15N, as well as 13C,13C correlation spectra of the protein-RNA complex. In addition, we established a methodology to determine accurate distance and angular restraints for the protein-RNA interface and propose approaches for the chemical shift assignment of RNA resonances.
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Wu, Xi-Li. "New techniques in nuclear magnetic resonance spectroscopy". Thesis, University of Cambridge, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.385872.
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Lucena, Alcalde Guillermo. "New developments in chromatographic NMR". Thesis, University of Sussex, 2018. http://sro.sussex.ac.uk/id/eprint/76636/.
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Analysis in chemistry has always been hindered by the presence of impurities in samples or mixtures that are difficult to separate. Nuclear magnetic resonance has proven to be one of the most powerful analysis techniques to enable the study of mixtures by pseudoseparation using molecular parameters such as the diffusion coefficient through the application of the DOSY technique. In order to extend the application of this technique, an improvement has been proposed know as matrix-assisted DOSY (MAD-DOSY) or chromatographic NMR. This technique is based on the addition of a sample modifier that will interact differently with the molecules, varying and separating their diffusion coefficients, or even changing slightly the chemical shifts. To extend the application of chromatographic NMR, size exclusion stationary phases have been combined with DOSY experiments. These studies have been applied to analyze mixtures modifying the diffusion coefficient in terms of size exclusion behavior and to increase the understanding of the interactions between the analytes and the stationary phase. These studies have been published in Magnetic Resonance in Chemistry. One of the main issues when using DOSY is spectral overlapping, which is the main cause of poor resolution. In addition to this problem, a consequence of using stationary phases is the appearance of increased broadening of the signals due to differences in magnetic susceptibility. Thus, to achieve the aim, the study of diffusion properties have been performed under HR-MAS conditions which can help to remove susceptibility effect, but has complicating effects on the DOSY experiment. A method to obtain reliable diffusion measurements under HR-MAS have been developed using a D2O sample. Different conditions have been investigated including different pulse sequences, variation of parameters of the pulse sequence (diffusion delay or gradient strength), spinning rate and synchronization of the pulse sequence with the sample spinning. Also improvements in sample preparation as the addition of spacers in different locations of the sample rotor, to both reduce radial field variations and the sample volume, in order to obtain the most accurate diffusion values. This method have been published in Magnetic Resonance in Chemistry. The method have been applied to a wide range of molecules to extend the understanding of diffusion under HR-MAS conditions. In order to extend the range of application of NMR chromatography, a complementary study of the analysis of a mixture of different enantiomers including ethylenediamine cobalt complexes, aminoacids and some other organic small molecules adding to the sample a chiral stationary phase as a sample modifier is included in the final chapter of this thesis.
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Dvoyashkina, Nina, Dieter Freude, Christopher F. Seidler, Michael Wark i Jürgen Haase. "Composite fuel cell materials studied by MAS PFG NMR diffusometry and MAS NMR spectroscopy". Universitätsbibliothek Leipzig, 2016. http://nbn-resolving.de/urn:nbn:de:bsz:15-qucosa-198097.
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Dvoyashkina, Nina, Dieter Freude, Christopher F. Seidler, Michael Wark i Jürgen Haase. "Composite fuel cell materials studied by MAS PFG NMR diffusometry and MAS NMR spectroscopy". Diffusion fundamentals 24 (2015) 12, S. 1, 2015. https://ul.qucosa.de/id/qucosa%3A14526.
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Brough, Adrian R. "Solid state NMR studies of inorganic materials". Thesis, University of Oxford, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.239312.
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