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Counter-current distribution of interacting molecules : simulation of distribution behaviour and application to protein-protein interactionsBackman, Lars January 1981 (has links)
Associations of biological macromolecules with other macromolecules, with larger assemblies of macromolecules and with themselves are widely encountered phenomena. In principle, these interactions can be studied with any method able to differentiate between free molecules and complexes formed. The most extensively used techniques are sedimentation equilibrium and velocity, elastic light scattering and molecular sieve chromatography. This thesis describes an alternative technique; counter-current distribution in aqueous two-phase systems. The counter-current distribution behaviour of a solute depends on its size and surface properties including charge and hydrophobicity. Since the surface properties of a complex formed most probably differ from those of the solutes participating in the association, complex formation should lead to changes in the average distribution behaviour of each solute. Consequently, the presence of one solute should affect the counter-current distribution of another solute if they interact with each other. In order to establish the boundary conditions and the potential as well as limitations of the counter-current distribution technique, the distribution behaviour of homogeneous and heterogeneous association equilibria have been simulated. The model developed for describing the distribution behaviour of heterogeneous associations has been tested using the well characterized interaction between bovine serum albumin and L-tryptophan. It was demonstrated that the theoretical model could predict the experimental distribution behaviour of these two molecules. However, the primary aim of the counter-current distribution experiments has been to gain insight into protein-protein interactions. The metabolically linked enzymes, malate dehydrogenase and aspartate aminotransferase, have been studied in order to determine if there is also a physical link between these two enzymes. The results showed that the cytosolic enzymes as well as the mitochondrial forms associate while the cytoplasmic enzymes did not display any association with the mitochondrial forms. Thus, an organelle specific interaction between malate dehydrogenase and aspartate aminotransferase was demonstrated. Hemoglobin and carbonic anhydrase are functionally linked through the Bohr effect. Thus, the binding of oxygen by hemoglobin in the lung capillaries is associated with the binding of protons which are formed by the catalytic action of carbonic anhydrase. From the counter- current distribution experiments it was possible to conclude that humain carbonic anhydrase II, the high activity form, associates with human hemoglobin whereas carbonic anhydrase I, the low activity form, did not show any affinity for hemoglobin. / digitalisering@umu.se
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Experimental studies of kinetic solvent deuterium isotope effects on proton abstraction in alcohol solutionLevin, Jan-Olof January 1974 (has links)
The present dissertation is an account based on investigations published in the following papers: I. JAN-OLGF LEVIN and CHRISTOFFER RAPPE, Solvent Deuterium Isotope Effects in Alcohols. I. Racemization of Phenyl2,2-Diphenylcyclopropyl Ketone, 3-Nethyl-4-phenyl-2-butanone and 2-Nethyl-1-indanone. Chem. Scr., 1, 233-235 (1971 ). II. JAN-0L0F LEVIN, Solvent Deuterium Isotope Effects in Alcohols. II. Effect of Solvent-Base System on Kinetic Solvent Isotope Effects in Fiydrogen Abstraction Reactions. Chem. Scr., 4, 85-88 (1973). III. JAN-0L0F LEVIN, Solvent Deuterium Isotope Effects in Alcohols. III. Alkoxide Catalyzed Racemizations of Indenes. Chem. Scr., J5, 89-91 (1974). IV. JAN-OL0F LEVIN, Solvent Deuterium Isotope Effects in Alcohols. IV. Hydrogen Abstraction Reactions in Alcohols Containing Amines. Chem. Scr., in press. These papers will be referred to by the Roman numerals I-IV. / digitalisering@umu.se
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Synthesis of ring-fused 2-pyridones with potential antibiotic propertiesWiderberg, Staffan January 2017 (has links)
No description available.
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Uptake and translocation ofcommon antibiotics in plants : Laboratory experiment and real-case study ofKwazulu-Natal, South Africa’s wastewater systemOesterle, Pierre January 2017 (has links)
No description available.
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Evaluation of sorption materials for the removal of organic micropollutants in domestic wastewater and their potential infiltration in groundwaterRostvall, Ande January 2017 (has links)
No description available.
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Characterization of dangerous pollutants in bio and waste ashes : Analysing content and leaching behaviour of several ashes for persistent organic pollutants and toxic heavy metalsMüller, Nils January 2017 (has links)
No description available.
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Rening av ett cytokrom c'-liknande protein från Ideonella dechloratans och studier av dess ligandbindningsegenskaperJohansson, Jens January 2013 (has links)
No description available.
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Interaction of PEG-ylated Lipid Nanoparticles with Silica SubstratesZhang, Xinchen January 2016 (has links)
In this project, the interaction between polyethylene glycol modified (PEG-ylated) lipid nanoparticles and silica substrates was studied to find out how this interaction was affected by bulk concentration, temperature and the composition of particles. One kind of lipodisk and four kinds of PEG-ylated liposome were prepared from lipid films and characterized by quartz crystal microbalance with dissipation monitoring (QCM-D) instrument mounted with silica sensor. The detailed information of particle-silica interaction could be obtained from the raw data, frequency and dissipation values, and the adsorbed mass surface density calculated from the raw data. Lipodisks could be immobilized on the silica surface. Whether they would be rinsed away by PBS buffer was influenced by both the bulk concentration and temperature. The way of their binding could change and the changing process was affected by temperature. PEG-ylated liposomes could also be immobilized on the silica surface, and they could break and spread to form supported lipid bilayer in certain conditions, for example, the changing of temperature or the using of certain lipids. Supported lipid bilayers were created with high reproducibility in this project, which could be very useful to the future study of transmembrane proteins functions and lipodisk properties.
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Conversion of Styrene Oxide to 2-Hydroxyacetophenone by Metabolic EngineeringTjärnhage, Elias January 2017 (has links)
No description available.
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Probing the effects of mutations on a proton transfer pathway in photosystem II on the oxygen evolution cycleJohan, Pettersson January 2017 (has links)
No description available.
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