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 20 for “"epimerase"”.
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Mechanistic studies on mannuronan C5-Epimerase
… aeruginosa algG gene product is a mannuronan C5-epimerase, which converts mannuronate to guluronate residues within the polysaccharide, alginate. The aim of this work was to purii' the epimerase and determine optimum reaction conditions for its enzymic activity. The epimerase was produced as an …
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Structural and Functional Characterization of B. Anthracis Udp-Glcnac 2-Epimerase and Salmonella Secreted Effector I
… Bacillus anthracis cell-wall enzyme UDP-GlcNAc 2-Epimerase and the Salmonella secreted virulence effector SseI. UDP-GlcNAc 2-Epimerase is an essential B. anthracis enzyme required for formation of the peptidoglycan cell wall precursor UDP-ManAc. We have solved the epimerase's crystal structure to …
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FROM GENE TO STRUCTURE: Formation of Iduronic Acid in Dermatan Sulfate by Two DS-epimerases
… identified that catalyzes this reaction, i.e. DS-epimerase 1 and 2. By using fold-recognition modeling a structural model was obtained for DS-epimerase 1, which enabled characterization of the active site of the enzyme with mutational analysis. A feature of a dermatan sulfate chain is the presence …
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Characterization of an ethanologenic yeast inhibiting atypical galactose metabolism
… suggesting involvement of UDP-galactose 4-epimerase in the responsible reaction mechanism(s).Sub-cellular fractionation was employed in an attempt to ascertain enzyme localization in Y-1528. Fermentations of lignocellulosic substrate mixtures by Y-1528 illustrated better performance than …
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Mini-Isoelektrofokussierung von Serum-Transferrin bei Patienten mit CDG-Syndrom
… gefunden: Einige Neugeborene mit Epimerase- Mangel zeigten überraschenderweise CDG Banden mit 0-3 SR. Diese Banden korrelierten nicht mit der Höhe der Galaktose-Metaboliten und verschwanden auch nicht nach einer diätetischen Behandlung. Diese Befunde unterscheiden sich von den …
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Biological Functions of Iduronic Acid in Chondroitin/Dermatan Sulfate in Tumor and Brain Development
… Epimerization is catalyzed by two enzymes, DS-epimerase 1 (DS-epi1) and 2 (DS-epi2), resulting in the formation of iduronic acid (IdoA). The aim of this thesis was to investigate the role of iduronic acid in cancer and brain development. The first part of this thesis gives a general review of …
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Chemical and Enzymatic Synthesis of Dehydropeptides and Their Fluoro Analogs
… D,L-difluoroalanine were treated with the epimerase YcjG to produce L-Ala-Dha and L-Ala-Dha(F), respectively, as determined by 1H NMR, 19F NMR and MS (ESI).
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Design of a Saccharomyces cerevisiae strain capable of simultaneously utilizing cellobiose and xylose
… the role of mutarotase, also called aldose 1-epimerase, which is capable of converting glucose between two anomers was investigated. Three endogenous mutarotase genesYHR210c, YNR071c and GAL10 were identified in S. cerevisiae s288c wild type strain. The natural cellobiose assimilating strain …
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Identifizierung und Analyse der an der pflanzlichen Zellwandbiosynthese beteiligten Gene in Arabidopsis thaliana
… die T-DNA Insertion im UGE3-Gen (UDP-Glukose Epimerase), einem Gen des Nukleotidzucker-Synthesewegs, erfolgt war. Die Mutante zeigt eine starke Verkürzung der Wurzellänge. Die Zellwandmonosaccharide dieser Mutante unterschieden sich nicht vom Wildtyp. Hingegen konnten Unterschiede in der …
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Discovery of Function in the Enolase Superfamily
… A novel D-Ala-D/L-Ala and a unique L-Ala-D/L-Glu epimerase (AEE) were identified and kinetically characterized from Cytophaga hutchinsonii (k cat/KM of 5.5 x 104 M -1s-1) and Bacteroides thetaiotaomicron (kcat/KM of 5.8 x 104 M-1s-1), respectively. Computational predictions, provided by Prof. …
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In Vitro Synthetic Biology Platform and Protein Engineering for Biorefinery
… isomerase, L-arabinose isomerase and xylulose 4-epimerase (Xu4E). Promiscuous activity of Xu4E, a monosaccharide C4-epimerase, was discovered for the first time. Directed evolution of Xu4E enabled to increase the catalytic function of C4-epimerization on D-xylulose as a substrate by more than …
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Discovery of function in the enolase superfamily
… A novel D-Ala-D/L-Ala and a unique L-Ala-D/L-Glu epimerase (AEE) were identified and kinetically characterized from Cytophaga hutchinsonii (kcat/KM of 5.5 x 104 M-1s-1) and Bacteroides thetaiotaomicron (kcat/KM of 5.8 x 104 M-1s-1), respectively. Computational predictions, provided by Prof. …
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Methanocaldococcus jannaschii and the Recycling of S-adenosyl-L-methionine
… phosphate pathway, ribulose 5-phosphate 3-epimerase and transketolase, were able to convert 5-deoxyribulose 1-phosphate to lactaldehyde. Lactaldehyde was then reduced to methylglyoxal by an essential enzyme in methanogenesis, N5, N10-methylenetetahydromethanopterin reductase with NADPH. …
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Expanding the Role of Oxidoreductases in Benzylisoquinoline Alkaloid Metabolism in Opium Poppy
… The fusion protein, renamed reticuline epimerase (REPI), was detected in opium poppy and in Papaver bracteatum, which accumulates the morphinan alkaloid thebaine. In contrast, orthologs encoding independent CYP and AKR enzymes catalyzing the respective synthesis and reduction of …
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Divergent Evolution of Enzymatic Activity: Functional Assignment and in Vitro Evolution in the MLE Subgroup of the Enolase Superfamily
… assign unknown proteins as L-Ala-D/L-Glu epimerases in several bacterial organisms, and studied those proteins from Escherichia coli and Bacillus subtilis in detail. The discovery of the L-Ala-D/L-Glu epimerases expands the repertoire of reactions catalyzed by the enolase superfamily, and …
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Untersuchungen zur Biosynthese der pflanzlichen Zellwand = [Identification and characterization of genes involved in plant cell wall synthesis]
… UDP-rhamnose synthase (RHM), UDP-glucuronic acid epimerase (GAE) and the myo-inositol oxygenase (MIOX) families. For the three-membered RHM family relative ubiquitous expression was shown using variuos methods. For one of these genes, RHM2, T-DNA lines could be obtained. Moreover, the …
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Identification and characterization of a novel class of hydrogen peroxide targets in escherichia coli
… the pathway, one protein, ribulose 5-phosphate 3-epimerase (Rpe), which requires a solvent-exposed divalent metal for activity, was found to be sensitive to H2O2 both in vivo and in vitro. Although Zn, Mn, Fe, and Co were found to activate Rpe to varying degrees, only Rpe loaded with Fe was …
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Superoxide stress in Escherichia coli
… dehydrogenase (Tdh), ribulose-5-phosphate 3-epimerase (Rpe), peptide deformylase (PDF), and DAHP synthase -- were shown to be inactivated in the Escherichia coli strain which lacks the ability to scavenge O2- (denoted as SOD- mutant). Moreover, the inactivation of DAHP synthase, the first …
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Strain engineering and biosensor development for efficient biofuel production by Saccharomyces cerevisiae
… important enzyme in glucose conversion, aldose 1-epimerase (AEP), was investigated. AEP is supposed to maintain the intracellular equilibrium of α-glucose and β-glucose when the spontaneous conversion between the two glucose anomers is not sufficient. However, the heterologous cellobiose …