Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 22 for “"tetrapyrrole"”.
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Lineare Tetrapyrrole in marinen Sedimenten
… 80iger Jahre wurde zum ersten Mal über lineare Tetrapyrrole als Abbauprodukte des Chlorophylls in seneszenten Pflanzen berichtet. Da jährlich mehr als 10 9 t Chlorophyll katabolisiert werden, davon etwa 3/4 im wäßrigen Milieu, stellt sich die Frage, ob lineare Tetrapyrrole ebenfalls in marinen …
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Synthesis and functionalizations of tetrapyrrole derivatives
… presents a brief overview of the history of tetrapyrrole derivatives and of their fundamental properties. Overviews of porphyrins, benzoporphyrins, chlorins and porphycenes are presented. Work presented in Chapter 2 through Chapter 4 mainly focuses on the syntheses and functionalization of …
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Tolyporphins, Unusual Tetrapyrrole Pigments from a Cyanobacterial-Microbial Holobiont.
North Carolina State University Theses Chemistry.
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Destruction of biological tetrapyrrole macrocycles by hypochlorous acid and its scavenging by lycopene
… play any role in the pattern of cleavage of the tetrapyrrole ring. Subsequent studies showed that treatment of cyanocobalamin with HOCl, also led to generation of proinflammatory reaction products such as cyanogens chloride. Given the role of HOCl in generating free iron and cyanogen chloride it …
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The F(430) cofactor of methyl coenzyme M reductase: Ligand binding to the nickel and chemical modification of the tetrapyrrole substituents
Chemical and spectroscopic studies on the nickel enzyme methyl-CoM reductase from M. thermoautotrophicum (strain $\Delta$H) were undertaken to better characterize the nickel site. The major goals of this work are two-fold: (1) To further characterize the molecular and electronic structure of the …
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Biochemical and chemical studies of the components involved in the final step of methane formation in Methanobacterium
… native coenzyme F430, a unique nickel-containing tetrapyrrole.
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The structure and reactivity of metallohydroporphyrins
… the highly reduced nickel-containing macrocyclic tetrapyrrole F$\sb{430}$, found in the latter enzyme of methanogenic bacteria. This cofactor possesses the most highly reduced porphyrin macrocycle yet encountered in nature.
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Apoptosis and porphyrin biosynthesis by a photodynamic chemotherapeutic
… by ALA is enhanced by addition of the tetrapyrrole modulator 1,10-phenanthroline (Oph), by enhancing Proto accumulation. We determined the efficacy and intracellular localization and biosynthesis of Proto, and the role of apoptosis in ALA- and Oph-mediated cell death of transformed …
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Photodynamic Herbicide Modulators
… of the damage-causing anabolic photodynamic tetrapyrroles that accumulated as a result of treatments that consisted of ALA and one chlorophyll biosynthesis modulator. Furthermore, DDV/LDV plant species were more susceptible to ALA-based dark treatments that lead to MV Pchlide accumulation, …
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Extracts from the prairie plant Symphoricarpos occidentalis or the natural product, Pheophorbide a, induce light-dependent vacuolation of human cells
… and phenotypic screening showed that the cyclic tetrapyrrole compound, Pheophorbide a, had a similar effect on human cells. Insight into cytoplasmic vacuolation might be beneficial as a tool to study nuclear envelope organization and contribute to the understanding of lamin-related diseases, such …
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Molecular Design and Photophysical Characterization of Synthetic Bacteriochlorins for Solar Energy Conversion and Photodynamic Therapy
… e.g., bacteriochlorophylls) are tetrapyrrole macrocycles with two reduced pyrrole rings, whereas chlorins: e.g., chlorophylls) and porphyrins: e.g., hemes) have one and zero reduced pyrrole rings. Molecular design characteristics are revealed by understanding the effects of …
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Investigating the Distribution and Biosynthesis of Modified F<sub>430</sub> Cofactors in Methanogenic and Methanotrophic Archaea
… F<sub>430</sub>, a unique nickel-containing tetrapyrrole, serves as the prosthetic group and catalytic component of Mcr. Recently, multiple F<sub>430</sub> variants have been discovered in several methanogenic species, including Methanococcus maripaludis, Methanosarcina acetivorans, and …
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Recombinant Expression and Assembly of Methyl Coenzyme-M reductase
… requires two molecules of its nickel-containing tetrapyrrole prosthetic group, coenzyme F430. Additionally, the α subunits of MCR house a variety of different post-translational modifications across both methanogens and ANME. In methanogens, MCR is encoded in a conserved mcrBDCGA gene cluster, …
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Bilirubin Nanoparticle As An Anti-Inflammatory Therapy For Graft Versus Host Disease
… in finding a therapy for GvHD. Bilirubin is a tetrapyrrole pigment, found in the blood, with natural anti-oxidative and anti-inflammatory properties. Using mouse models of various inflammatory diseases, studies by our collaborating investigators have shown that, water-soluble PEGylated …
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Investigation of the Structure and Kinetics of Heme-Containing Proteins Using Magnetic Circular Dichroism and Rapid-Scan, Stopped-Flow Spectroscopy
… all heme proteins, the iron metal center and the tetrapyrrole macrocycle, UV-visible (UV-Vis) electronic absorption and rapid-scan, stopped-flow spectroscopies were utilized to determine reaction mechanisms and kinetics data. Due to the chromophore properties of heme-containing proteins, magnetic …
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Understanding the Effects of Higher-Order Assembly on the Structure of Sulfite Reductase
… that contains a siroheme (iron- containing tetrapyrrole) cofactor at the active site covalently coupled with Fe4S4 cluster through cysteine conjugations. Chapter 1 provides an introduction of multi domain oxidoreductases with a main focus on SiR and its homologs. Chapter 2 provides …
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Dynamics of soybean leaf hydraulic conductance and diurnal soybean transcriptome analysis
… the most diurnally responsive genes included tetrapyrrole synthesis, C1 (methyl and formate) metabolism, and major CHO metabolism (starch and sucrose). These changes were linked to typical diurnal cycles in soybean photosynthesis and metabolism, and diurnal expression patterns for individual …
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Investigating the provision of vitamin B₁₂ in the Micro-Ecological Life Support System Alternative (MELiSSA) loop for long-distance space exploration using algal-bacterial cocultures.
… is a corrinoid molecule, composed of a modified tetrapyrrole ring- with a cobalt ion at the centre and various possible upper and lower axial ligands. Vitamin B₁₂ is synthesised only by certain prokaryotes and the process requires over 20 enzymatic reactions. On Earth, most humans fulfil their …
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