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Influence of cultivation conditions on the production of recombinant proteins
Gardošová, Zuzana ; Nováčková, Ivana (referee) ; Brázda, Václav (advisor)
Recombinant proteins are produced by using genetic modifications. In this process is insert contained gene encoding a certain protein in a cloning vector cloned into the host organism. Recombinant proteins are expressed after the transformation of the cloning vector into a host, the host organism. The expression of recombinant proteins in bacterial cells is one of the most efficient ways to manufacture these proteins. The p53 protein is a tumor suppressor protein, the main role in cells is to react on DNA damage. Due to the reaction to various intracellular and extracellular stimuli, including DNA damage, the p53 protein shows different biological functions, including regulation of senescence, cell cycle, or apoptosis. The theoretical part of the thesis part presents the basic properties of proteins, methods of recombinant protein expression, methods of protein isolation, and characterization of p53 protein. The aim of the experimental part was to determine the effect of incubation temperature on recombinant p53 protein production. The work involves the isolation of plasmid DNA and its transformation into E. coli production cells. The produced proteins were successfully isolated and subsequently characterized by SDS-PAGE and Western Blotting.
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Heterologous expression and isolation of human cytochrome P450 1B1
Sojka, Pavel ; Martínek, Václav (advisor) ; Moserová, Michaela (referee)
Cytochromes P450 are heme enzymes with very broad substrate specificity, they can oxidize tens to hundreds of different substrates including both eobiotics and xenobiotics, but with varying efficiencies and kinetics. They are responsible for the metabolic activation of many carcinogens resulting in formation of reactive intermediates, these reactive species participate in the formation of DNA adducts and also increase of oxidative stress. Eukaryotic cytochromes P450 are membrane bound enzymes found mostly in the endoplasmic reticulum. In vertebrates, they are expressed in a variety of tissues mostly in the liver, but also in kidney, lung, skin and others. The cytochrome P450 1B1 is an inducible enzyme which occurs mainly in the lung and skin. Its expression is induced predominantly by the presence of polycyclic aromatic hydrocarbons, dioxins and heterocyclic amines. The human cytochromes P450 are typically obtained using heterologous expression and isolated as a C-terminally modified hexa-histaq constructs using immobilized metal affinity chromatography. This thesis focuses on effect of C-terminal modifications on activity of human cytochrome P450 1B1. First, the two expression vectors encoding the human form of cytochrome P450 1B1 were prepared, one contained a classical C-terminal hexa-histaq...
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Heterologous expression of human NADPH:cytochrome P450 reductase
Mazurová, Martina ; Martínek, Václav (advisor) ; Ingr, Marek (referee)
Study of carcinogenesis is associated with study of xenobiotics metabolism, which is topic studied in our laboratory. Mixed-function oxygenase system (MFO system) is significantly contributing to the metabolism of xenobiotics. Pure recombinant proteins participating in MFO system are frequently utilized in in vitro metabolic experiments. The heterologous expression method is often used to obtain the pure recombinant enzymes. Heterologous expression was employed to prepare human NADPH:cytochrome P450 oxidoreductase. This membrane enzyme reduces cytochrome P450 and enables its catalytic activity. Vectors with synthetic gene for human NADPH:cytochrome P450 oxidoreductase based on pUC19 and pET22b plasmids were prepared and verified. Recombinant protein was produced in E. coli BL21-Gold and E. coli BL21-CodonPlus-RIL cells. Both cell strains produced high levels of the protein; however the major part of the protein was present predominantly in inclusion bodies. Expression conditions were therefore optimized to obtain higher yields of native protein bound in bacterial membrane fraction. [In Czech]
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Influence of cultivation conditions on the production of recombinant proteins
Gardošová, Zuzana ; Nováčková, Ivana (referee) ; Brázda, Václav (advisor)
Recombinant proteins are produced by using genetic modifications. In this process is insert contained gene encoding a certain protein in a cloning vector cloned into the host organism. Recombinant proteins are expressed after the transformation of the cloning vector into a host, the host organism. The expression of recombinant proteins in bacterial cells is one of the most efficient ways to manufacture these proteins. The p53 protein is a tumor suppressor protein, the main role in cells is to react on DNA damage. Due to the reaction to various intracellular and extracellular stimuli, including DNA damage, the p53 protein shows different biological functions, including regulation of senescence, cell cycle, or apoptosis. The theoretical part of the thesis part presents the basic properties of proteins, methods of recombinant protein expression, methods of protein isolation, and characterization of p53 protein. The aim of the experimental part was to determine the effect of incubation temperature on recombinant p53 protein production. The work involves the isolation of plasmid DNA and its transformation into E. coli production cells. The produced proteins were successfully isolated and subsequently characterized by SDS-PAGE and Western Blotting.
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Preparation of a plasmid, its expression and preliminary isolation of MafK protein - the interacting partner of heme sensor Bach1
Mihalčin, Peter ; Martínková, Markéta (advisor) ; Stráňava, Martin (referee)
Bakalárska práca Abstract Heme-sensing proteins are heme proteins to which heme serves as a signalling molecule. Association or dissociation of heme moiety and heme-sensing proteins influences various physiological functions, such as enzyme activity or gene expression regulated by these heme-sensing proteins. The main object of this thesis is heme-sensing protein Bach1 and its interaction partner, transcription factor MafK. Bach1 refers to the group of transcription factors involved in repression of gene expression. The target genes of Bach1 regulation are hemeoxygenase genes. Hemeoxygenase controls the excess free heme degradation. Due to the excess of free heme in the cell, Bach1-heme interaction inactivates Bach1 controlled repression of hemeoxygenase resulting in the free heme degradation. In the state of physiological free heme concentration, Bach1-heme interaction does not occur and activated Bach1 represses the hemeoxygenase expression via binding to the target gene enhancers. Bach1 is incapable of making efficient Bach1-DNA bonding by itself, therefore the transcription factor MafK is essential. Protein MafK modulates the Bach1-DNA binding by making the heterodimer formation Bach1-MafK, which binds to DNA. The first aim of this thesis is to summarize the recent knowledge about transcriptional...
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Characteristics of expression vectors for Corynebacterium glutamicum and their use for studies of sigma factors of RNA polymerase
Dvořáková, Pavla ; Pátek, Miroslav (advisor) ; Konopásek, Ivo (referee)
The aim of the thesis was to characterize chosen expression vectors used in biotechnologically important bacterial species, Corynebacterium glutamicum, and to test their use in studies of promoter activity control by sigma factors of RNA polymerase. Different properties of these vectors (level of expression of the cloned gene, leaky expression without inducer, dependence of expression level on inducer concentration and cell population homogeneity) were found by determination of expression level of the model gfpuv gene by fluorescence intensity assay of the produced protein and by gfpuv-expressing C. glutamicum cell population analysis using flow cytometry. The vector pEC-XT99A was chosen for testing the bi-plasmid system for assignment of a sigma factor to the chosen promoter. Although the level of expression provided by pEC-XT99A was not high, the vector showed no leaky expression, expression from the vector was comparable for a wide range of IPTG concentrations and the cell population was homogenous concerning the gene expression. Using pEC-XT99A from which individual stress sig genes were expressed, the σD factor was clearly assigned to the up-to-now unknown Pcg0420 promoter. Another vector for isolation and purification of C. glutamicum proteins was used to express the C. glutamicum sigM gene and to...
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Study of secretory granules from insulin-producing tissues and cell lines.
Halušková, Petra ; Žáková, Lenka (advisor) ; Koblas, Tomáš (referee)
Pancreas is known to be an organ producing a variety of exocrine and endocrine substances, where also insulin belongs. This hormone is produced in the body almost solely by specialized β-cells of the Langerhans islets and is stored here in secretory granules. As the β-cells contain large number of these vesicles, an organism can quickly respond to the glucose stimulation. Completely processed insulin is formed in the secretory granules probably as a hexamer, where six insulin molecules are coordinated along two zinc bivalent cations. Appropriate β-cell response to higher glucose level and following insulin secretion is one of the key processes that regulate metabolism in the body. In order to study insulin production, its effects or secretion, permanent pancreatic cell lines are often used as biological models, out of primary cells from islets of Langerhans. This diploma thesis is focused on two permanent cell lines INS-1E and BRIN-BD11. We searched for the ability of the cells to produce insulin, if the hormone is fully processed, as well as zinc content, which could have a great influence on insulin's processing. Using different methods we compared these two cell lines with cells from the Langerhans islets. We succeeded in isolation of secretory granules from all three cell types and we plan to...
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Heterologous expression and isolation of human cytochrome P450 1B1
Sojka, Pavel ; Martínek, Václav (advisor) ; Moserová, Michaela (referee)
Cytochromes P450 are heme enzymes with very broad substrate specificity, they can oxidize tens to hundreds of different substrates including both eobiotics and xenobiotics, but with varying efficiencies and kinetics. They are responsible for the metabolic activation of many carcinogens resulting in formation of reactive intermediates, these reactive species participate in the formation of DNA adducts and also increase of oxidative stress. Eukaryotic cytochromes P450 are membrane bound enzymes found mostly in the endoplasmic reticulum. In vertebrates, they are expressed in a variety of tissues mostly in the liver, but also in kidney, lung, skin and others. The cytochrome P450 1B1 is an inducible enzyme which occurs mainly in the lung and skin. Its expression is induced predominantly by the presence of polycyclic aromatic hydrocarbons, dioxins and heterocyclic amines. The human cytochromes P450 are typically obtained using heterologous expression and isolated as a C-terminally modified hexa-histaq constructs using immobilized metal affinity chromatography. This thesis focuses on effect of C-terminal modifications on activity of human cytochrome P450 1B1. First, the two expression vectors encoding the human form of cytochrome P450 1B1 were prepared, one contained a classical C-terminal hexa-histaq...
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Heterologous expression of human NADPH:cytochrome P450 reductase
Mazurová, Martina ; Martínek, Václav (advisor) ; Ingr, Marek (referee)
Study of carcinogenesis is associated with study of xenobiotics metabolism, which is topic studied in our laboratory. Mixed-function oxygenase system (MFO system) is significantly contributing to the metabolism of xenobiotics. Pure recombinant proteins participating in MFO system are frequently utilized in in vitro metabolic experiments. The heterologous expression method is often used to obtain the pure recombinant enzymes. Heterologous expression was employed to prepare human NADPH:cytochrome P450 oxidoreductase. This membrane enzyme reduces cytochrome P450 and enables its catalytic activity. Vectors with synthetic gene for human NADPH:cytochrome P450 oxidoreductase based on pUC19 and pET22b plasmids were prepared and verified. Recombinant protein was produced in E. coli BL21-Gold and E. coli BL21-CodonPlus-RIL cells. Both cell strains produced high levels of the protein; however the major part of the protein was present predominantly in inclusion bodies. Expression conditions were therefore optimized to obtain higher yields of native protein bound in bacterial membrane fraction. [In Czech]
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