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1	Carbohydrate directed photoaffinity labelling Fowle, Chris January 2018 (has links) Glycoproteins have diverse and essential roles within biological systems. They are formed by enzymatic addition of saccharides to proteins during, or shortly after, translation. However, saccharides can also react with proteins non-enzymatically, a process termed glycation, which can cause impaired function and improper folding. Glycated proteins further react to form advanced glycation end-products, which have been implicated in the pathogenesis and progress of many diseases. Due to this pathological effect, glycation has been studied as a potential biomarker of these diseases. Photoaffinity labelling is a technique that is used to investigate the structure, and presence, of biological molecules; a precedent exists for its use in the study of carbohydrates in biological systems. Chapter 1 outlines the background of this thesis exploring previous studies of glycation, its effects, and methods used in recognition and photoaffinity labelling. Chapter 2 details the design and synthesis of a novel photoaffinity probe, and the optimisation of this synthesis. The target molecule was successfully produced and simpler alternatives to the initial synthetic route with similar yields are discussed. In Chapter 3 the use of the photoaffinity probe is studied. Labelling trials were performed on three proteins: human serum albumin (HSA), macrophage migration inhibitory factor (MIF), and casein. Mass spectrometry showed that the experiments with both HSA and MIF were successful, while the procedure appeared to lead to degradation of casein. Additionally, our work into developing techniques for identifying labelled samples is detailed. A diol-doped electrophoresis gel was not successful created, however, staining protein samples in polyacrylamide gel electrophoresis with curcumin showed promise. Chapter 4 explores the electrochemistry of the photoaffinity probe and details the use of the probe in functionalising a fluorine doped tin oxide (FTO) glass electrode. Cyclic voltammograms of Alizarin Red S (ARS), obtained using a treated electrode, suggest that surface functionalisation was successful. 540
2	Mapování protein-proteinových interakcí systému cytochromu P-450 metodami chemické modifikace a hmotnostní spektrometrie / Protein-protein interaction mapping of cytochrome P-450 by methods using chemical modification and mass spectrometry Ječmen, Tomáš January 2010 (has links) Cytochromes P-450 (P450s) belong to haemoprotein superfamily and they are responsible for metabolism of a wide variety of compounds, among others many drugs and carcinogens. P450s serve as the terminal oxidases in the mixed function oxidase system in cooperation with a redox partner NADPH: cytochrome P450 reductase (CPR) providing input of two electrons to the reaction cycle of P450. The CPR can be substituted by other redox partner of P450, cytochrome b5 (cyt b5), to deliver the second electron. Three dimensional structure of P450 is required in order to fully understand its reaction mechanism. At the present time, a homology model of cytochrome P-450 2B4 (CYP 2B4) is available in our laboratory. In this study, the mapping of interaction domain between CYP 2B4 and cyt b5 employing a crosslinking agent EDC to form amide bonds between close complementary charged amino acid side chains was the first goal. We have identified five interacting amino acid pairs in total using mass spectrometry (MS). The second research interest was to verify and refine the CYP 2B4 model using a photoaffinity labelling with N-(p-azidobenzyl)-N-methyl-p-aminophenylamine probe. This photoreactive probe is known as CYP 2B4 ligand binding to the central iron atom of haem. After photoactivation the arginine 197 was found by MS...
3	Structural and Functional Regulation of the Human Chloride/Proton ClC-5 by ATP and Scaffold NHERF2 Interactions Wellhauser, Leigh Anne 18 January 2012 (has links) The chloride/proton antiporter ClC-5 is primarily expressed in the kidney where it aids in re-absorption of proteins from the glomerular filtrate. Functional disruption of ClC-5 causes Dent’s Disease – a renal condition characterized by proteinuria and kidney failure in a third of all cases. The majority of disease-causing mutations translate into premature truncations of the carboxy-terminal (Ct) region of ClC-5 and are predicted to disrupt the protein-protein interactions mediated by this domain. In this thesis, direct ATP binding to the two cystathionine β-synthase (CBS) domains of ClC-5 was demonstrated. ATP binding enhanced the global compactness of the ClC-5 Ct region likely through a clamping motion of the CBS domains around the nucleotide. Along with ATP, the sodium proton exchange regulatory factor 2 (NHERF2) also binds ClC-5; however, the molecular mechanism behind this interaction was unknown as ClC-5 lacked the PDZ binding motif traditionally localized at the Ct end of bait proteins. Here, we also identified a class I PDZ binding motif (657-660; TSII) within the internal sequence of ClC-5. Despite the buried position of this motif in the Ct peptide’s X-ray crystal structure (PDB: 2J9L), the high propensity of this region for dynamic flexibility prompted us to test whether it could mediate NHERF2 interactions. In support of this hypothesis, we demonstrated that the motif is transiently available to interact directly with NHERF2 in vivo and to enable an enhancement in receptor-mediated endocytosis in mammalian cells. Collectively, these results gave further evidence that the intracellular Ct region of ClC-5 serves as a hub to mediate interactions essential for its maturation, stability, and trafficking in renal epithelium, as well as providing further insights into the molecular basis of Dent’s Disease. ClC-5 CBS Domains ATP Binding Site NHERF2 SAXS Thermal Stability Photoaffinity Labelling Endocytosis Internal PDZ Binding Motifs 0487
4	Structural and Functional Regulation of the Human Chloride/Proton ClC-5 by ATP and Scaffold NHERF2 Interactions Wellhauser, Leigh Anne 18 January 2012 (has links) The chloride/proton antiporter ClC-5 is primarily expressed in the kidney where it aids in re-absorption of proteins from the glomerular filtrate. Functional disruption of ClC-5 causes Dent’s Disease – a renal condition characterized by proteinuria and kidney failure in a third of all cases. The majority of disease-causing mutations translate into premature truncations of the carboxy-terminal (Ct) region of ClC-5 and are predicted to disrupt the protein-protein interactions mediated by this domain. In this thesis, direct ATP binding to the two cystathionine β-synthase (CBS) domains of ClC-5 was demonstrated. ATP binding enhanced the global compactness of the ClC-5 Ct region likely through a clamping motion of the CBS domains around the nucleotide. Along with ATP, the sodium proton exchange regulatory factor 2 (NHERF2) also binds ClC-5; however, the molecular mechanism behind this interaction was unknown as ClC-5 lacked the PDZ binding motif traditionally localized at the Ct end of bait proteins. Here, we also identified a class I PDZ binding motif (657-660; TSII) within the internal sequence of ClC-5. Despite the buried position of this motif in the Ct peptide’s X-ray crystal structure (PDB: 2J9L), the high propensity of this region for dynamic flexibility prompted us to test whether it could mediate NHERF2 interactions. In support of this hypothesis, we demonstrated that the motif is transiently available to interact directly with NHERF2 in vivo and to enable an enhancement in receptor-mediated endocytosis in mammalian cells. Collectively, these results gave further evidence that the intracellular Ct region of ClC-5 serves as a hub to mediate interactions essential for its maturation, stability, and trafficking in renal epithelium, as well as providing further insights into the molecular basis of Dent’s Disease. ClC-5 CBS Domains ATP Binding Site NHERF2 SAXS Thermal Stability Photoaffinity Labelling Endocytosis Internal PDZ Binding Motifs 0487
5	Untersuchungen zur Biosynthese und Aktivität ausgewählter Plecomakrolide sowie chemisches Screening von Actinomyceten / Studies on the Biosynthesis and Activity of Selected Plecomacrolides and Chemical Screening of Actinomycetes Schuhmann, Tim 25 January 2005 (has links) No description available. 540 Chemie Mathematics and Computer Science Naturstoffe Neue Sekundärmetabolite Streptomyceten Bafilomycin Concanamycin Makrolide V-ATPase-Hemmstoffe Diazirinylgruppe NMR Methoxymalonyl-Einheit Concanamycin-Biosynthesegencluster Isolierung Strukturaufklärung Photoaffinitätsmarkierung Natural Products Novel Secondary Metabolites Streptomycetes Bafilomycin Concanamycin Macrolides V-ATPase Inhibitor Diazirinyl Group NMR Methoxymalonyl Unit Isolation Structure Elucidation Photoaffinity Labelling 35.50 35.25

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