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 14 of 14 for “"Outer Membrane Porin"”.
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Outer Membrane Porin Regulation among Different Sequence Types of Escherichia coli Clinical Isolates
… E. coli can decrease the permeability of its outer membrane through porin downregulation, contributing to β-lactam resistance. Aberrations in permeability correlate with decreased carbapenem susceptibility when the organism produces an extended-spectrum β-lactamase or plasmid-encoded AmpC. …
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Engineered Vesicles for Perchlorate Degradation
… copolymer vesicle functionalized with the outer membrane porin OmpF. The porin allows for perchlorate transport into the vesicles, inside which the encapsulated enzymes transform perchlorate to chloride. Perchlorate reduction was quantified using a methyl viologen colorimetric technique. …
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Characterization of β-lactamases and Porins in Uropathogenic E. coli
… extended spectrum β-lactamases, AmpC cephalosporinases, and serine-carbapanemases. Decreased drug influx due to outer membrane porin defects can confer resistance to the carbapenems when paired with the production of the ESBLs and AmpCs. In this study, the mRNA and protein expression of the …
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Protein glycosylation in the gram-negative gamma proteobacterium photorhabdus luminescens
… conclusively using mass spectrometry to be an outer membrane porin, OmpN. No glycoproteins have previously been identified in P. luminescens. The ompN gene was cloned and expressed in both Escherichia coli and P. luminescens. It was found that OmpN purified from P. luminescens was capable of …
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Early interaction between pseudomonas aeruginosa and polarized human bronchial epithelial cells
… On the other hand, 395 genes, including oprG outer membrane porin and pscP involved in type III secretion system were down regulated. To understand the roles of these differentially expressed genes, a cytotoxicity (LDH release) assay was performed and demonstrated that oprG and ion mutants …
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Structural Insights into Modification and Export of the Pseudomonas aeruginosa Alginate Exopolysaccharide
… precursors are polymerized by Alg8 in the inner membrane upon cyclic diguanylate binding to Alg44. Following polymerization and translocation into the periplasm, the polymer can be modified by epimerization by AlgG, or acetylation by the concerted action of AlgI, AlgJ, AlgF, and AlgX. We proposed …
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Modification and Translocation of the Biofilm Exopolysaccharide Poly-β(1,6)-N-acetyl-D-glucosamine
… respectively. E. coli PgaB is a two-domain outer membrane lipoprotein that continually associates with PNAG throughout periplasmic translocation. Studies described herein suggest that PgaB binds and deacetylates PNAG along the cleft between the N- and C-terminal domains in a processive-like …
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Characterization of the MexT Regulator of the mexEF-oprN Multidrug Efflux Operon of Pseudomonas aeruginosa
… promoter region and the oprD gene, encoding an outer membrane porin that provides a portal of entry for basic amino acids and carbapenem, whose expression was reduced only by GSNO.
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Mechanism of tocopherol transfer by human α-tocopherol transfer protein (α-hTTP)
… simply diffused from 6-His-a-hTTP to acceptor membranes since the kinetics of transfer were not responsive to a variety of conditions tested. After a series of trouble shooting experiments, we identified a minor contaminant, E coli. outer membrane porin F (OmpF) that co-purified with …
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Interactions of Fe(II) with the iron oxidizing bacterium Rhodopseudomonas palustris TIE-1
… Fe(Il): PioA, a decaheme cytochrome, PioB, an outer membrane porin, and PioC, a high potential iron protein (HiPIP). These proteins suggested a model of Fe(II) oxidation that ends with transfer of electrons to the photosynthetic reaction center. The goal of this thesis was to test and extend …
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Pseudomonas aeruginosa OprD-Family Porins Facilitate Imipenem Translocation Resulting in AmpC β-Lactamase Induction Contributing to the Effectiveness of Imipenem/Relebactam
… resistance has been tied to the depletion of the outer membrane porin, OprD and overproduction of AmpC chromosomal β-lactamase. It is not known how relebactam potentiates imipenem when AmpC levels are low, nor how imipenem traffics into the cell in the absence of OprD. The purpose of this …
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Surface Localization Determinants of Borrelia burgdorferi Lipoproteins
… burgdorferi, emphasized the importance of outer surface lipo-proteins (Osps) during the infectious cycle. Although the functions of these lipoproteins and the complex mechanism of differential regulation is known in increasing detail, it remains to be understood how these virulence factors …
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Beyond MICS: Determining the Role of Porin Production and β-Lactamase Expression in Resistance and Cellular Physiology of Klebsiella pneumoniae
… expression of β-lactamases and downregulation of outer membrane porins. However, the extent to which these mechanisms interplay in a resistant phenotype is not well understood. β-lactamase expression has long been presumed to have a previously unidentified fitness cost. In fact, little is known …
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Molecular Mechanisms of Antibacterial Resistance Among Pseudomonas aeruginosa: Multi-Drug Efflux Pumps and Their Interactions with Other Resistance Mechanisms
… previously suggested in the literature, nor the outer membrane porin OprD. Therefore, hypersusceptibility to imipenem may be linked to downregulation of a yet unidentified pump, changes in target, or increased permeability of the drug through a mechanism unrelated to OprD. Our studies …