Dissertations / Theses on the topic 'Biotin transporter'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 16 dissertations / theses for your research on the topic 'Biotin transporter.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse dissertations / theses on a wide variety of disciplines and organise your bibliography correctly.
Kirsch, Franziska. "Analyse der Substratbindestelle, der Stöchiometrie und der Transportfunktion von S-Einheiten bakterieller ECF-Transporter." Doctoral thesis, Humboldt-Universität zu Berlin, Lebenswissenschaftliche Fakultät, 2015. http://dx.doi.org/10.18452/17404.
Full textEnergy-coupling factor (ECF) transporters are uptake systems for vitamins and transition metal cations in prokaryotes. They consist of the two unrelated membrane proteins S and T, and a pair of ABC ATPases (A). The S unit mediates substrate specificity. The combination of the T and the A units is called ECF. In this thesis the controversially discussed stoichiometry of the subunits of ECF transporters and the postulated substrate transport function of solitary S units without ECF were analysed. For this purpose, the biotin-specific ECF transporter BioMNY, several biotin-specific S units (BioY) encoded in organisms lacking any recognizable ECF and two metal-specific ECF transporters were used. The S unit BioY of the tripartite biotin importer existed in vitro as monomer and dimer. Furthermore, oligomeric BioY was observed in living bacterial cells. Oligomerisation of a part of the T unit BioN in the BioMNY complex was shown by “pull-down”- experiments. Growth analyses confirmed the transport function of eight solitary BioY proteins. The dimerisation, also proved for these solitary BioY proteins in vitro, could be an explanation for the transport function of BioY without ECF. The metal-specific S units CbiM/NikM interact with additional and for the transport function essential transmembrane proteins (N). The S units consist of seven transmembrane helices and an extremely conserved N-terminus, which extends deeply into the protein. The metal-binding site consists of four nitrogen atoms from Met1, His2 and His67 and is stabilised by a series of hydrogen bonds. The transport function of CbiMN and Nik(MN) without ECF was verified respectively in vivo using the nickel-depending enzyme urease as an indicator for intracellular nickel concentration, respectively. However, the role of the N component, which is essential for transport activity, is currently under investigation.
Zuo, Shusheng. "Quantitation, Purification and Reconstitution of the Red Blood Cell Glucose Transporter GLUT1." Doctoral thesis, Uppsala : Acta Universitatis Upsaliensis : Univ-bibl. [distributör], 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-5727.
Full textLagerquist, Hägglund Christine. "Affinity-, Partition- and Permeability Properties of the Human Red Blood Cell Membrane and Biomembrane Models, with Emphasis on the GLUT1 Glucose Transporter." Doctoral thesis, Uppsala University, Department of Biochemistry, 2003. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-3525.
Full textThe human glucose transporter GLUT1 is abundant in red blood cells, the blood-brain barrier and epithelial cells, where it mediates the transport of the energy metabolite, glucose. In the present work some properties of GLUT1, including affinity binding of both substrates and inhibitors, transport rates as well as permeabilities of aromatic amino acids and drug-membrane interactions were analyzed by chromatographic methods.
Reconstitution by size-exclusion chromatography on Superdex 75 from a detergent with a low CMC that provides monomeric GLUT1 was examined regarding D-glucose- and CB binding as well as D-glucose transport. Upon steric immobilization in Superdex 200 gel beads, residual detergent could be washed away and dissociation constants in the same range as reported for binding to GLUT1 reconstituted from other detergents were obtained. The transport rate into the GLUT1 proteoliposomes was low, probably due to residual detergent. Binding to GLUT1 at different pH was analyzed and the affinity of glucose and GLUT1 inhibitors was found to decrease with increasing pH (5–8.7). The average number of cytochalasin B-binding sites per GLUT1 monomers was, in most cases, approximately 0.4. GLUT1 may work as a functional monomer, dimer or oligomer. To determine whether GLUT1 was responsible for the transport of the aromatic amino acids tyrosine and tryptophan, uptake values and permeabilities of these amino acids into liposomes and GLUT1 proteoliposomes were compared to the permeabilities of D- and L- glucose in the same systems. Dihydrocytochalasin B was identified to be a new inhibitor of tyrosine and tryptophan transport into red blood cells. Ethanol turned out to inhibit the specific binding between CB and GLUT1 and also to decrease the partitioning of CB and drugs into lipid bilayers. A capacity factor for drug partitioning into membranes that allows comparison between columns with different amount of immobilized lipids was validated, and turned out to be independent of flow rate, amount of lipids and drug concentration in the ranges tested.
Rasamoelisolo, Michèle. "Caracterisation biochimique des anticorps monoclonaux antiglycophorine a : utilisation de la glycophorine a en tant que transporteurs de substances biologiquement actives (doctorat : immunologie)." Nantes, 1997. http://www.theses.fr/1997NANT01VS.
Full textStephan, Milena. "Development of a Biomembrane Sensor Based on Reflectometry." Doctoral thesis, Niedersächsische Staats- und Universitätsbibliothek Göttingen, 2013. http://hdl.handle.net/11858/00-1735-0000-0001-BB7E-B.
Full textChiteri, Kevin Oyale. "Functional & Phylogenetic Analysis of Arabidopsis thaliana Organic Cation Transporters (OCT5 & OCT1) Genes in Polyamine Transport in Plants." Bowling Green State University / OhioLINK, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=bgsu1563038129138996.
Full textWaltz, Fanny. "Etude du transport de l'iode par chémogénomique." Thesis, Paris 11, 2011. http://www.theses.fr/2011PA112214/document.
Full textAn important breakthrough in the understanding of the mechanisms governing the process of iodide transport inside thyroid cells has been the cloning in 1996 of the protein responsible for this transport : the Na/I symporter (NIS). Different studies have been conducted ever since in order characterize this protein as well as the mechanisms which regulate its expression and its activity. Nevertheless, the cellular mechanisms of transport regulation and the proteins implied in the posttranslational regulation of the symporter remain largely unknown. The full understanding of these mechanisms would allow the treatment improvement of a lot of patients. Iodide transport is indeed involved not only in different thyroid pathologies, but also in radioactive iodide contaminations following nuclear accidents and in promising anticancer strategies by gene transfer. Chemogenomics, also called chemical genetics, is a multidisciplinary approach which goal is to explore the living systems thanks to small organic molecules. To better understand the mechanisms which govern iodide transport, our laboratory has set up a direct chemical genetic strategy which allowed us first to discover 10 molecules able to inhibit iodide transport. The objective of this thesis was to identify the protein targets of two molecules : ITB5 and ITB2. Electrophysiological and isotopic flux studies showed that these two molecules have a different mechanism of action. Their study should then allow the identification of at least two proteins involved in iodide transport.To identify the protein targets of ITB5 and ITB2, different probes were synthesized. These probes are made from the compound of interest, a photoactivable group allowing the creation, under light irradiation, of a covalent bound with the protein target(s) and a Biotin or Desthiobiotine molecule to extract the labeled proteins from cellular lysates. Once labeled and captured on agarose-Streptavidin beads, the proteins of interest were separated on SDS-PAGE gels stained either with silver nitrate or Coomassie blue. The corresponding bands were excised, digested by trypsin and the obtained peptides analyzed by mass spectrometry. A query made in the data bank Swissprot with the data obtained after the experiments conducted with the probe ITB5-P2 allowed us to identify 3 proteins apparently interacting with the compound ITB5. The experiments based on ITB2 had to be suspended because of a lack of time but encouraging results have been obtained. A band which may correspond to a protein specifically labeled by the probe ITB2-P1 has indeed been observed on a Western-blot after a first on-bead capture experiment. However, we couldn’t visualize it on a gel because of the important presence of proteins captured non specifically by the beads. The capture experimental conditions were optimized with the compound ITB5. These conditions will now be applied to the compound ITB2 and this should allow us to obtain cleaner gels on which the band of interest will be excised for an analyze by mass spectrometry
Piffeteau-Lecoeur, Annie. "Transport et métabolisation de la biotine et de quelques analogues structuraux dans les cellules de E. Coli." Paris 7, 1986. http://www.theses.fr/1986PA077093.
Full textGarcía, Gamuz José Antonio. "Caracterización hidrodinámica y fenomenológica de membranas selectivas." Doctoral thesis, Universidad de Murcia, 2009. http://hdl.handle.net/10803/10842.
Full textFrom the experimental study of the ionic transport through selective membranes in biionic systems, a simple model which allows the characterising hydrodynamic of the membrane systems through the determination of diffusion coefficients and the thickness of the limit layer has been developed. With this purpose, a rotating diffusion cell that allows the setting of hydrodynamic conditions clearly for the membrane system has been used, studying the variation of the conductivity and the pH in the external phase (receiving) at different temperatures from 20ºC to 50ºC and at different rotating velocities ω. The measurement of the fluxes, once set its dependence with ω, allows obtained the diffusion coefficients cationics in the membrane system in accordance with the temperature and ω. The measurements of the conductivity allow the testing of this model, through its correlation with the values of the pH measured, obtaining additional data about the diffusion coefficient of the cations in the receiving phase.
Sun, Xiangfei. "Modeling the Biota Population Impact on Polychlorinated Biphenyls Transport and Simulating PCBs Anaerobic Biodegradation in the Lake System." Research Showcase @ CMU, 2018. http://repository.cmu.edu/dissertations/1148.
Full textTang, Weiwei. "Expression, purification and characterization of the Biotin transporter from Staphylococcus aureus." Thesis, 2014. http://hdl.handle.net/2440/96159.
Full textThesis (M.Phil.) -- University of Adelaide, School of Molecular and Biomedical Science, 2014
Azhar, Al. "Structure-function relationships of the biotin transporters from Staphylococcus aureus." Thesis, 2015. http://hdl.handle.net/2440/102580.
Full textThesis (Ph.D.) -- University of Adelaide, School of Biological Sciences, 2015.
Ringlstetter, Stefan Ludwig [Verfasser]. "Identification of the biotin transporter in Escherichia coli, biotinylation of histones in Saccharomyces cerevisiae and analysis of biotin sensing in Saccharomyces cerevisiae / vorgelegt von Stefan Ludwig Ringlstetter." 2010. http://d-nb.info/101186178X/34.
Full textBreia, Richard Maykel Gonçalves. "Biotic stress in grapevine – elucidation of the role of the newly identified SWEET transporters on plant-pathogen interaction." Doctoral thesis, 2020. http://hdl.handle.net/1822/76114.
Full textOs açúcares desempenham funções vitais nos seres vivos, principalmente como fontes de carbono e de energia, mas também como reguladores osmóticos e como moléculas sinalizadoras. Em particular, na videira (Vitis vinífera L.), a qualidade do vinho depende dos níveis de açúcar nos bagos de uva porque determinam a concentração em etanol e influenciam a síntese de compostos secundários (incluindo pigmentos). Diferentes famílias de transportadores membranares presentes no genoma das plantas desempenham um papel essencial na translocação de açúcares entre os tecidos fotossintéticos e os tecidos de armazenamento. Entre eles, os transportadores denominados SWEET (Sugars Will Eventually be Exported Transporter), recentemente identificados, têm revelado diferentes papéis em mecanismos fisiológicos onde o efluxo de açúcar é fundamental, como nos nectários. Na videira, a família SWEET compreende 17 membros. No presente estudo pretendeu-se elucidar o papel dos VvSWEETs na resposta da videira à infeção por fungos (Botrytis cinerea e Erysiphe necator) e ao stresse abiótico, incluindo a secura. Além disso, para estudar os papéis fisiológicos do VvSWEET7 e VvSWEET15, foram aplicadas diferentes técnicas de engenharia genética de plantas, tal como CRISPR-Cas9. Em particular, na variedade Trincadeira, susceptível ao fungo B. cinerea, e na variedade Carignan, susceptível a E. necator, foram analisadas em detalhe as modificações no perfil de expressão dos SWEETs em bagos de uva infetados. Os resultados mostraram que a infeção por E. necator causa modificações mais pronunciadas na expressão dos VvSWEETs do que a infecção por Botrytis. Por outro lado, a maioria dos SWEETs da videira foram regulados negativamente em bagos de uva em resposta à secura, no entanto, o VvSWEET10 e VvSWEET11 foram regulados positivamente. Foi também observado que a expressão do VvSWEET1, VvSWEET4 e VvSWEET11 é regulada positivamente em folhas tratadas com caulino (filme inerte usado para proteger as videiras em situações de deficit hídrico, de radiação solar extrema e de ondas de calor), sugerindo que este mineral estimula a capacidade de transporte de sacarose entre os tecidos fotossintéticos e os tecidos de armazenamento. Estudos subsequentes mostraram que os genes VvSWEET11 e VvSWEET15 são positivamente regulados em bagos de uva submetidos a temperaturas de 50ºC durante 7 dias, tratamento normalmente usado para a produção de uvas passas. Uma vez que os níveis de transcritos dos genes VvSWEET7 e VvSWEET15 foram elevados nos bagos de uva e aumentaram em resposta à infeção por Botrytis, as proteínas VvSWEET7 e VvSWEET15 foram alvo de estudos adicionais para se avaliar a sua localização sub-celular e função. As proteínas de fusão VvSWEET7-GFP e VvSWEET15- GFP foram transitoriamente expressas em células da epiderme de Nicotiana benthamiana e os resultados de microscopia confocal mostraram que ambas as proteínas se localizam claramente na membrana plasmática. Após expressão heteróloga numa estirpe mutante de Saccharomyces cerevisiae (hxt-null), a proteína VvSWEET7 foi caracterizada funcionalmente como um transportador de glucose e de sacarose (Km =15,4 mM glucose e Km = 40,1 mM sacarose). Ensaios de inibição competitiva mostraram que o manitol e o sorbitol inibem o transporte de D-[14C(U)]- glucose, sugerindo que, além de mono- e de dissacarídeos, o VvSWEET7 medeia o transporte de polióis. No presente trabalho foram ainda identificados no genoma da videira 18 membros da família de transportadores de açúcares denominada ERD6like e a proteína VvERD6l13 foi alvo de um estudo mais aprofundado. A proteína de fusão VvERD6l13-GFP foi transitoriamente expressa em folhas de N. benthamiana após transformação mediada por Agrobacterium e os resultados de microscopia de fluorescência mostraram que se localiza na membrana plasmática. Estudos de transporte de açúcares marcados radioativamente, após expressão heteróloga em leveduras mutantes (hxt-null), mostraram que a proteína VvERD6l13 é um transportador de sacarose com protões (Km = 33 mM). O gene VvERD6l13 é fortemente regulado em bagos de uva infetados com Botrytis ou E. necator, sugerindo que a proteína VvERD6l13 tem um papel importante durante a interação planta-patógeno. Além disso, o VvERD6l13 é expresso em diferentes tecidos da videira, em particular na raiz. Genericamente, os resultados mostraram que os transportadores VvSWEET e o VvERD6l desempenham um papel importante na mobilização de açúcares durante o desenvolvimento dos bagos de uva e que a sua expressão é regulada ao nível da transcrição em resposta ao stresse biótico e abiótico. No seu conjunto, estes resultados ajudam a compor o puzzle complexo dos mecanismos de resposta da videira aos stresses biótico e abiótico, abrindo ainda caminhos novos e desafiadores no tópico do transporte transmembranar em plantas.
Sugars perform vital functions in the living world, primarily as sources of carbon and energy, but also as osmotic regulators and signaling molecules, among others. This is particularly relevant in the grapevine (Vitis vinifera L.) as the quality of the wine depends on the sugar concentration in the grape berry as it determines the final concentration in ethanol, but is also tightly related to the amount of secondary compounds (including pigments) synthesized during ripening. Different sugar transporter families are present in the genome of plants to fulfill the task of transmembrane sugar transport, which is pivotal for long distance transport between sources and sinks. Among these, the newly identified SWEETs transporters (from Sugars Will Eventually be Exported Transporter) have important roles in numerous physiological mechanisms where sugar efflux is critical. In grapevine, the SWEET family comprises 17 members. In this study, the main objective was to elucidate the role of VvSWEETs in grapevine response to fungal attack (Botrytis cinerea or Erysiphe necator infection) and abiotic stress, including drought. Also, to further study the physiological roles of VvSWEET7 and VvSWEET15, different plant genetic engineering techniques, such as CRISPRCas9, were used. In the B. cinerea-susceptible cv. Trincadeira and in the E. necator-susceptible cv. Carignan, modifications in the gene expression profile of SWEETs in infected grape berries were thoroughly analyzed. Overall, results showed that E. necator infection caused more pronounced modifications in VvSWEET gene expression than Botrytis infection. Moreover, the majority of grapevine SWEET genes were down-regulated in berries from droughtstressed vines of cv. Tempranillo, while VvSWEET10 and VvSWEET11 were up-regulated. In kaolin-treated leaves the expression of VvSWEET1, VvSWEET4 and VvSWEET11 was up-regulated, suggesting that this chemically inert mineral used to protect vines from radiation, drought and heat stimulates sucrose transport capacity improving source-to-sink transport of sucrose. Results also showed that VvSWEET11 and VvSWEET15 were strongly up-regulated in berries subjected to 50ºC during 7 days, a protocol normally used to produce raisins. Following the observation that VvSWEET7 and VvSWEET15 were strongly expressed in berries and clearly up-regulated in response to Botrytis infection in cv. Trincadeira, they were subjected to additional studies to evaluate the subcellular localization and function of the encoded proteins. VvSWEET7-GFP and VvSWEET15-GFP fusion proteins were transiently expressed in Nicotiana benthamiana epidermal cells after Agrobacterium-mediated transformation and both proteins clearly localized to the plasma membrane, as assessed by confocal microscopy. VvSWEET7 was functionally characterized after overexpression in an hxt-null Saccharomyces cerevisiae strain as a low-affinity, high-capacity glucose and sucrose transporter, with a Km of 15.4 mM for glucose and 40.1 mM for sucrose. Competitive inhibition experiments showed that mannitol and sorbitol also inhibited D-[14C(U)]-glucose transport, suggesting that, besides mono- and disaccharides, VvSWEET7 mediates the transport of polyols. In the grapevine genome 18 members of the sugar transporter family ERD6l were identified and VvERD6l13 was selected for further characterization. The fusion protein VvERD6l13-GFP was transiently expressed in N. benthamiana leaves after Agrobacterium-mediated transformation. VvERD6l13 is localized in the plasma membrane. When VvERD6l13 was heterologously expressed in an hxt-null S. cerevisiae strain, it was observed that the protein mediates H+-dependent sucrose transport with a Km = 33 mM. VvERD6l13 is strongly up-regulated in infected grape berries with Botrytis or E. necator, suggesting that it plays an important role during pathogen-host plant interaction. Moreover, VvERD6l13 is expressed in different grapevine tissues, but its steady-state transcript levels were particularly high in roots. In sum, VvSWEET and VvERD6l transporters are important players in sugar mobilization during grape berry development and their expression is transcriptionally reprogrammed in response to biotic and abiotic stress. Together, these results constitute a new piece of the complex puzzle that is grapevine interaction with its surrounding environment and existing biological threats, while also opening new and exciting pathways in the plant sugar transporter research topic.
Fundação para a Ciência e Tecnologia (FCT) - Bolsa de Doutoramento (PD/BD/113616/2015), integrada no Programa Doutoral “Agricultural Production Chains-From Fork to Farm (AgriChains) (PD/00122/2012). Fundação para a Ciência e Tecnologia (FCT) e Fundos Europeus (FEDER/POCI /COMPETE2020) – Projecto “MitiVineDrought - Combining "omics" with molecular, biochemical and physiological analyses as an integrated effort to validate novel and easy-to-implement drought mitigation strategies in grapevine while reducing water use” (PTDC/BIA-FBT/30341/2017 and POCI-01-0145-FEDER-030341). Fundação para a Ciência e Tecnologia (FCT) e Fundos Europeus (FEDER/POCI /COMPETE2020) – Projecto “BerryPlastid - Biosynthesis of secondary compounds in the grape berry: unlocking the role of the plastid” (POCI-01-0145-FEDER-028165 and PTDC/BIA-FBT/28165/2017). Fundação para a Ciência e Tecnologia (FCT) – Projecto “GrapInfectomics - Transcriptome and metabolome reprogramming in Vitis vinifera cv. Aragonês and Vitis rupestris berries upon infection with Erysiphe necator” (PTDC/ASP-HOR/28485/2017). Fundação para a Ciência e Tecnologia (FCT) – Projecto “CherryCrackLess” - Cherry cracking & mitigation strategies: towards their understanding using a functional metabolomic approach” (PTDC/AGRPRO/ 7028/2014).
Boruchowicz, Hugo. "Identification des partenaires de gM du virus VHS-1 par BioID couplée à la spectrométrie de masse." Thèse, 2019. http://hdl.handle.net/1866/22813.
Full textDesrochers, Valérie. "Utilisation de microboutures de saule pour prévenir le développement d'espèces indésirables." Thèse, 2019. http://hdl.handle.net/1866/22741.
Full text