Дисертації з теми "Salmonella typhimurium LT 2"
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Simmons, James Walter. "O-Acetylserine Sulhydralase-A from Salmonella typhimurium LT-2: Thermodynamic Properties and SPectral Identification of Intermediates." Thesis, University of North Texas, 1993. https://digital.library.unt.edu/ark:/67531/metadc278042/.
Повний текст джерелаŽindul, Adam. "Salmonella enterica Serovar Typhimurium inaktyvacijos fotosensibilizacija vertinimas ir poveikio modeliavimas." Master's thesis, Lithuanian Academic Libraries Network (LABT), 2014. http://vddb.library.lt/obj/LT-eLABa-0001:E.02~2011~D_20140701_164247-99768.
Повний текст джерелаEvaluation of Salmonella enterica Serovar Typhimurium inactivation by photosensitization and impact modeling The aim goal of this research is to evaluate the influence of irradiation of UV light and incubation period on Salmonella enterica Serovar Typhimurium bacteria. Shortly discussed most commonly used mathematical models of bacterial inactivation, expressed lag phase and its function. Next step is evaluation of line part and tail of inactivation (mortality) curve. At the end of the research the inactivation formula is deduced and the results are discussed.
Figueira, Ana Rita. "Analysis of effectors of the Salmonella Typhimurium SPI-2 type three secretion system." Thesis, Imperial College London, 2011. http://hdl.handle.net/10044/1/9287.
Повний текст джерелаKrogan, Nevan John. "Utilization of dihydroorotate by S. typhimurium LT-2, characterization of the dhpA gene." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape7/PQDD_0007/MQ45331.pdf.
Повний текст джерелаCea, Medina Pablo Antonio. "Caracterización bioquímica de la 4-amino-5-hidroximetil-2-metilpirimidina quinasa de Salmonella typhimurium y Thermus thermophilus." Tesis, Universidad de Chile, 2019. http://repositorio.uchile.cl/handle/2250/168116.
Повний текст джерелаLa 4-amino-5-hidroximetil-2-metilpirimidina quinasa (HMPK, EC 2.7.1.49) es una enzima perteneciente a la superfamilia riboquinasa y participa en la biosíntesis de tiamina (vitamina B1) en bacterias. Se ha descrito que esta enzima es capaz de catalizar dos fosforilaciones consecutivas dependientes de ATP altamente específicas sobre el sustrato hidroximetil pirimidina (HMP), generando como producto hidroximetil pirimidina pirofosfato. Esto contrasta notablemente con lo que se ha observado en las piridoxal quinasas de bacterias Gram positivas (HMPK/PLK, EC 2.7.1.35), un grupo de enzimas homólogas cercanas capaces de fosforilar hidroximetil pirimidina, piridoxal, piridoxina y piridoxamina, pero incapaces de catalizar dos fosforilaciones consecutivas, por lo que sólo producen hidroximetil pirimidina fosfato. Las HMPKs no han sido estudiadas tan exhaustivamente como las HMPK/PLKs y sólo hay dos caracterizaciones breves disponibles en la literatura; la de la HMPK de Escherichia coli y la de Bacillus subtilis. Por lo tanto, aún no se conoce si las propiedades observadas en las enzimas descritas son ubicuas para linajes bacterianos distintos, especialmente aquellos filogenéticamente distantes y que han sido sometido a presiones selectivas fuertes, como los extremófilos. Por esta razón, en este trabajo se realizó la caracterización bioquímica de la HMPK de la enterobacteria Salmonella typhimurium (StHMPK) y de la bacteria termófila Thermus thermophilus (TtHMPK). A través de experimentos de estequiometría de reacción y análisis de generación de productos, se demostró que ambas enzimas son capaces de catalizar dos fosforilaciones consecutivas. Experimentos de especificidad de sustrato revelaron que ambas enzimas son altamente específicas por hidroximetil pirimidina. Análisis filogenéticos mostraron que estas enzimas están estrechamente relacionadas con las HMPKs/PLK de organismos gram positivos, y estas últimas parecen ser descendientes directos de las HMPKs. Por lo tanto, para estudiar cómo estos grupos de enzimas han divergido en términos de sus actividades catalíticas, se realizaron simulaciones de dinámica molecular del complejo ternario (Mg·ATP - HMP) de StHMPK, para analizar el sitio de unión a sustrato y compararlo con el de la HMPK/PLK de Staphylococcus aureus (SaPLK). Los resultados mostraron que existe un alto grado de conservación entre ambos sitios, existiendo sólo unas pocas diferencias que podrían explicar la divergencia funcional observada, principalmente la presencia de una treonina adyacente a la base catalítica en StHMPK, que es reemplazada por una alanina en SaPLK, y la presencia de una glutamina en StHMPK que forma puentes de hidrógeno con el HMP. La caracterización cinética de StHMPK y TtHMPK mostró que ambas enzimas poseen una KM similar para HMP (cercana a 30μM) y que la Vmax para TtHMPK es un orden de magnitud menor que para StHMPK a 37 °C. Sin embargo, estos parámetros fueron obtenidos para las curvas de saturación de HMP, las cuales mostraban un comportamiento del tipo Michaelis-Menten, mientras que las curvas de saturación para ATP mostraron una clara desviación de este modelo y por lo tanto, no se pudieron determinar parámetros cinéticos. Finalmente, se realizó una caracterización estructural y biofísica para evaluar diferencias de estabilidad. Ambas enzimas parecen ser monómeros en las condiciones estudiadas, a diferencia de lo reportado para la enzima de E. coli que forma un tetrámero. Experimentos de desplegamiento por temperatura y agentes químicos mostraron que TtHMPK es significativamente más estable que StHMPK. Las bases estructurales de estas diferencias fueron analizadas mediante simulaciones de dinámica molecular, las que revelaron que la proteína termoestable es más rígida, tiene un menor contenido de residuos polares en el núcleo y tiene mayor cantidad de interacciones electrostáticas que su homólogo mesoestable.
4-amino-5-hydroxymethyl-2-methylpyrimidine kinase (HMPK, EC 2.7.1.49) is a bacterial enzyme that belongs to the ribokinase superfamily and participates in the thiamine (vitamine B1) biosynthetic pathway. It has been described that this enzyme is capable to catalyze two consecutive highly specific ATP dependent phosphorylations on the substrate hydroxymethyl pyrimidine, yielding hydroxymethyl pyrimidine pyrophosphate. This contrast notoriously with what has been observed for the closely related homologous enzymes pyridoxal kinases from Gram positive bacteria (HMPK/PLK, EC 2.7.1.35), which can phosphorylate hydroxymethyl pyrimidine, pyridoxal, pyridoxine and pyridoxamine, but are unable to catalyze two consecutive phosphorylations, thus only produce hydroxymethyl pyrimidine phosphate. HMPKs have not been as extensively studied as HMPKs/PLK, and only two brief biochemical characterizations are available on the literature; the characterization of the HMPK from Escherichia coli and from Bacillus subtilis. Therefore, it is still unknown whether the properties observed in the described enzymes are ubiquitous among different bacterial lineages, especially those that come from a very distinct phylogenetic background and have been subject to strong selective pressures, as the enzymes from extremophilic organisms. For this reason, in this work we address the biochemical characterization of the HMPK from the enterobacteria Salmonella typhimurium (StHMPK) and the thermophilic bacteria Thermus thermophilus (TtHMPK). Through stoichiometric experiments and product generation analysis, it was established that both enzymes are able to perform two consecutive phosphorylations. Substrate specificity experiments revealed that both enzymes are highly specific for hydroxymethyl pyrimidine. Phylogenetic analysis of these enzymes showed that are closely related to HMPKs/PLK from Gram positive organisms, being the later a direct descendant from HMPKs. Therefore, to study how these two groups of enzymes have diverged so much in terms of their catalytic activities, we analysed the substrate binding site of StHMPK by molecular dynamics simulations of the ternary complex (Mg·ATP - HMP) and compared it to the binding site of the PLK from Staphylococcus aureus (SaPLK). The results showed that there is an overall great conservation among the active sites, with just a few differences that could be responsible for the functional divergences observed, mainly the presence of a threonine residue adjacent to the catalytic base in StHMPK which is replaced by an alanine in SaPLK, and the presence of a glutamine that forms hydrogen bonds with the HMP in StHMPK. Kinetic characterization of StHMPK and TtHMPK showed that both enzymes have a similar KM for HMP (around 30 μM) while the Vmax for TtHMPK is one order of magnitude lower than the Vmax for StHMPK. However, these parameters were obtained only for HMP saturation curves, which showed a Michaelis-Menten behaviour, whereas ATP saturation curves displayed a clear deviation from a Michaelis-Menten model and therefore, no kinetic parameters could be deduced from these experiments. Finally, a biophysical and structural characterization to assess stability differences was performed. Both enzymes seem to be in monomeric state under the conditions assayed, in contrast with what was reported for the enzyme from E. coli, which forms a tetramer. Thermal and chemical unfolding experiments showed that TtHMPK is significantly more stable than StHMPK. The structural basis for these differences were investigated through molecular dynamics simulations, which revealed that the thermostable protein is more rigid, has a reduced content of polar amino acids in its core, and has more electrostatic interactions than its mesostable homologous.
Julio del 2019
Barreto, Arce Liz Judith. "Efecto de la lactoferrina bovina en la invasión de Salmonella typhimurium cepa SL 1344 a células HEp-2." Master's thesis, Universidad Nacional Mayor de San Marcos, 2017. https://hdl.handle.net/20.500.12672/6131.
Повний текст джерелаTesis
Havemann, Gregory Dale. "Polyhedral Organelles involved in the B12-dependent metabolism of 1, 2-propanediol in Salmonella enterica serovar typhimurium LT2." [Gainesville, Fla.] : University of Florida, 2003. http://purl.fcla.edu/fcla/etd/UFE0000697.
Повний текст джерелаMarjoshi, Delphine. "Investigating the effects of three herbicides - Kamba, 2,4-D and Roundup on Salmonella enteric serovar Typhimurium growth and antibiotic tolerance phenotypes." Thesis, University of Canterbury. School of Biological Sciences, 2014. http://hdl.handle.net/10092/10284.
Повний текст джерелаRaux, Evelyne Christine. "Biosynthesis of cobalamin (vitamin Bâ†1â†2) in Salmonella typhimurium and Bacillus megaterium de Bary : characterisation of the anaerobic pathway." Thesis, University College London (University of London), 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.313359.
Повний текст джерелаDeschenes, Marianne. "Régulation de la réponse immunitaire in vivo et in vitro au cours de l'infection chronique par Salmonella typhimurium." Paris 11, 1989. http://www.theses.fr/1989PA114803.
Повний текст джерелаROCHA, Tatiane Martins. "Controle de Salmonella Typhimurium em frangos de corte uti- lizando composto com ácido benzóico, fumárico e 2-hidróxi-me- tiltio-butanóico." Universidade Federal de Goiás, 2008. http://repositorio.bc.ufg.br/tede/handle/tde/936.
Повний текст джерелаFoi conduzido um experimento utilizando-se 630 pintos com um dia de idade com o objetivo de avaliar os efeitos de ácidos orgânicos, frente à inoculação experimental de Salmonella Typhimurium sobre a saúde intestinal, desempenho, bacteriologia de órgãos e função hepática. As aves foram distribuídas em delineamento inteiramente ao acaso com seis tratamentos e sete repetições com 15 pintos cada. O desafio experimental com a bactéria ocorreu por duas vias de administração: via inglúvio, ao primeiro dia após eclosão, e via ração durante o período de sete a 14 dias de idade. Estes grupos foram tratados ou não com ácidos orgânicos, definindo-se desta forma, um esquema fatorial de 3x2 (agente versus ácidos orgânicos). Os pintos dos tratamentos preconizados para inoculação no primeiro dia de vida receberam via inglúvio, a dose de 5,0 x 102 /0,5mL unidades formadoras de colônias (UFC) de Salmonella Typhimurium. Os tratamentos com contaminação via ração, receberam o desafio na dosagem de 5,0 x 102 UFC de Salmonella Typhimurium/ kg de ração. O teste de Tukey (5%) foi utilizado para análises das variáveis. Os grupos tratados com ácidos orgânicos apresentaram melhores de ganho de peso, peso médio e conversão alimentar (p<0,05) aos 14, 21 e de ganho de peso e peso médio (p<0,05) aos 28 dias de idade. Os grupos inoculados com Salmonella Typhimurium apresentaram piores índices de desempenho (p<0,05) aos sete, 14 e 28 dias. O peso do intestino delgado foi maior (p<0,05) para os grupos inoculados quando comparado ao grupo controle, entretanto com comprimento menor para o mesmo fragmento intestinal. O tratamento inoculado via inglúvio e tratado com ácidos orgânicos apresentou menores valores (p<0,05) de unidades formadoras de colônia/g de Escherichia coli em excretas do que os grupos que foi comparado. O pH do conteúdo do conteúdo cecal e do intestino delgado não foi afetado (p>0,05) pela adição de ácido, enquanto o pH do intestino delgado dos grupos inoculados foi menor (p<0,05) quando comparado ao grupo controle negativo durante todo o período experimental. Também foi verificado menor peso (p<0,05) de fígado para os grupos controle negativo aos 21 e 28 dias. Os grupos tratados com ácido, independente da via de administração com Salmonella Typhimurium, obtiveram menores freqüências de isolamento em todos os órgãos analisados. Foram também observadas alterações (p<0,05) na bioquímica sérica hepática e na análise histopatológica do fígado pela atuação da Salmonella. Pode-se concluir que o ácido utilizado na dosagem de 0,4% potencializou o desempenho, foi eficaz no controle de Salmonella Typhimurium e não promoveu lesões hepáticas, quando da inoculação experimental de Salmonella Typhimurium ácido nalidíxico resistente.
Okamoto, Andre Kimura. "Estudo teorico das relações estrutura - atividade biologica sobre a inibição por cumarinas da mutagenese induzida pela 2-amino-3-metilimizado [4,5 - f] quinolina em Salmonella typhimurium TA98." [s.n.], 2002. http://repositorio.unicamp.br/jspui/handle/REPOSIP/249728.
Повний текст джерелаDissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Quimica
Made available in DSpace on 2018-08-03T05:32:54Z (GMT). No. of bitstreams: 1 Okamoto_AndreKimura_M.pdf: 9235596 bytes, checksum: c2080072a6edb12399c9deb5463ffb17 (MD5) Previous issue date: 2002
Mestrado
Widmer, Kenneth Walter. "Influence of autoinducer 2 (AI-2) and AI-2 inhibitors generated from processed poultry on virulence and growth of Salmonella enterica serovar Typhimurium." 2007. http://hdl.handle.net/1969.1/ETD-TAMU-1313.
Повний текст джерелаLin, Wei-Ting, and 林煒庭. "Attenuated Salmonella enterica serovar Typhimurium expressing DEN-2 NS1 antigen effectively immunizes mice against dengue virus challenge." Thesis, 2004. http://ndltd.ncl.edu.tw/handle/36633676190162953355.
Повний текст джерела國防醫學院
微生物及免疫學研究所
92
The objects of this study contains three fold; firstly, to investigate the expression of NS1 protein of Dengue virus via a Caf1 cherapone/usher secretion pathway; secondly, to study the immune response to NS1:Caf1 fusion protein delivered by attenuated Salmonella typhimurium SL1344 strain in a murine infection model; and thirdly, to determine whether protein priming-oral Salmonella boosting immunization against the Dengue NS1 antigen could induce a protective immune response against Dengue virus challenge. Our results demonstrated that NS1 antigen of Dengue virus could be successfully expressed as a NS1:Caf1 fusion protein and secreted on the surface of the cells in both E.coli and Salmonella via Caf1 secretion system. In particular overexpression of Caf1A resulted in higher level of soluble NS1:Caf1 protein present in the extracellular compartment as compared to that of the non-induced one. This results indicated that Caf1A may also play a critical role in promotion of the assembly and folding of sCaf1 (signal sequence) targeting polypeptide, such as NS1:Caf1 fusion protein. However, mice administrated with single oral dose of S.typhimurium SL1344/pLT105 was not appeared to be eliciting high level of specific anti-NS1 serum titer. But it was significantly increased by 2-3 fold in the anti-NS1 serum titer when co-dosed with amphotericin B suggesting that amphotericin B was likely to be as a potential adjuvant for Salmonella oral vaccine. Furthermore, co-dosing with AmB and S. typhimurium SL1344/pLT105 mice obtained 70% protection against the Dengue virus challenge in comparison with that of 30 % for S.typhimurium SL1344/pLT105 alone. In addition mice immunized with a parenteral NS1 protein vaccine followed by an oral boosting with S. typhimurium SL1344/pLT105 could obtain better protection than by single immunized regime. Taken together the results clearly demonstrated that Dengue NS1 protein antigen could be expressed as a soluble NS1:Caf1 fusion protein and highly displayed on the cell surface in E. coli and Salmonella. Single oral dose with S. typhimurium SL1344/pLT105 could confer partial protection for mice against lethal dose of Dengue virus challenge. Protein priming-oral Salmonella boosting regime could provide an effective way to increasely elicit protective immune response to against Dengue virus challenge. As an adjuvant amphotericin B is able to augment the immune response for Salmonella oral vaccine.
TSAI, CHUNG CHIN, and 蔡忠勤. "Secretion of recombinant dengue-2 NS1 protein via the Caf1 protein secretion system in Salmonella enterica serovar Typhimurium aroA." Thesis, 2002. http://ndltd.ncl.edu.tw/handle/87923434429457742761.
Повний текст джерела國防醫學院
微生物及免疫學研究所
90
The Caf1 capsule protein is encoded by the Caf1 gene cluster of Yersinia pestis. It is secreted via the Caf1 M chaperone/Caf1 A usher pathway. We investigated the ability of this secretion system to facilitate secretion of dengue virus type 2 NS1 full-length protein fused to the Caf1 subunit in Escherichia coli and Salmonella enterica serovar Typhimurium aroA. The processed product consisting of mature NS1 and Caf1 remained insoluble in spite of correct processing of this chimeric protein. However, co-expression of this chimera with a functional Caf1 M chaperone led to the accumulation of soluble NS1:Caf1 in the periplasm, which can be released by osmotic shock. Souble NS1:Caf1 reacted with monoclonal antibody directed against structural epitopes of NS1 protein. The result suggest that Caf1 M-induced release of NS1:Caf1 from the plasma membrane promotes folding of the NS1 domain. In this system, gene encoding chimeric protein was created in which the NS1 was sandwiched between the Caf1 signal peptide and the mature Caf1 subunit, leaving the C terminus of the nature of the N-terminal heterologous protein, the Caf1 domain of the chimera remained free to interact with Caf1 M and that this interaction enhanced the solubility of the periplasmic NS1 protein. Following co-expressing of NS1:Caf1 with both Caf1 M chaperone and Caf1 A outer membrane protein. NS1:Caf1 fusion protein could be detected on the cell surface and in the culture broth of E. coli and Salmonella enterica serovar Typhimurium aroA . These results indicate the potential application of the Caf1 protein secretion system in the transport of NS1:Caf1 fusion protein.
Simanshu, Dhirendra Kumar. "Structural Studies On Enzymes From Salmonella Typhimurium Involved In Propionate Metabolism: Biodegradative Threonine Deaminase, Propionate Kinase And 2-Methylisocitrate Lyase." Thesis, 2006. http://hdl.handle.net/2005/329.
Повний текст джерелаChittori, Sagar. "Metabolic Adaptation For Utilization Of Short-Chain Fatty Acids In Salmonella Typhimurium : Structural And Functional Studies On 2-methylcitrate Synthase, Acetate And Propionate Kinases." Thesis, 2011. http://etd.iisc.ernet.in/handle/2005/2209.
Повний текст джерелаHui, Patrick J. H. "Small Proline Rich Protein-2 Expression and Regulation in the Caco-2 model of Intestinal Epithelial Differentiation along the Crypt-Villus Axis." Thesis, 2008. http://hdl.handle.net/1974/1183.
Повний текст джерелаThesis (Master, Anatomy & Cell Biology) -- Queen's University, 2008-04-25 12:39:06.427
This work was funded by the CIHR GIDRU Training Grant and Aid in Research from Crohn's and Colitis Foundation of Canada