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Significance of the S1 subsite of rhomboid intramembrane proteases for catalysis and inhibitor design
Kučerová, Jolana ; Stříšovský, Kvido (advisor) ; Hodek, Petr (referee)
This thesis focuses on the development of specific inhibitors of rhomboid intramembrane proteases. These inhibitors are needed for the cell-biological investigation of rhomboid proteases and their potential pharmacological targeting, as rhomboid proteases have been associated with various diseases, such as malaria, Parkinson's disease, cancer or toxoplasmosis. The thesis advisor's laboratory has recently discovered the first such group of compounds, the peptidyl ketoamides. To exploit them fully, it is necessary to examine their properties and the possibilities of their modifications. In this work, synthetic fluorogenic substrates and enzyme kinetics were used to examine the possibilities of exploiting the S1 subsite in the rhomboid active site for rhomboid inhibitor design. Furthermore, using variants of these substrates modified by unnatural amino acids in the P1 position, the mechanism of water transfer to the rhomboid active site was investigated. Comparison of cleavage rates of ten fluorogenic substrates modified in the P1 position revealed that the E. coli rhomboid protease GlpG strongly prefers side chains -CH2-CH3 and -CH3 in the P1 position (i.e. binding into the S1 subsite). This trend was apparent also with peptidyl ketoamide inhibitors. The present substrate and inhibitor study suggests...
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Study of interactions between low-molecular mass compounds and the DNA-binding domain of forkhead transcription factor FOXO3
Kohoutová, Klára ; Obšil, Tomáš (advisor) ; Žáková, Lenka (referee)
This bachelor thesis is part of a project focused on studying low-molecular mass compounds able to inhibit the interaction between DNA-binding domain of human forkhead transcription factor FOXO3 and the target DNA. FOXO3 is one of four members of FOXO class transcription factors which belong to forkhead family of transcription factors. Forkhead transcription factors are evolutionary conserved proteins playing important roles in numerous cellular processes. These include cell-cycle regulation, oxidative stress response, control of cellular metabolism and apoptosis. FOXO3 plays an important role in cancer cells where it acts not only as a tumor suppressor but also can enhance their resistance to chemotherapy. Considering its biological functions, the study of small-molecule inhibitors of FOXO3 transcription factor is of particular importance. This bachelor thesis was focused on compound S9 oxalate as a potential inhibitor of FOXO3-DNA interaction. Main goals of this thesis were: (I) preparation of both unlabeled and 15 N labeled DNA- binding domain of FOXO3 transcription factor, (II) characterization of interactions between FOXO3 DBD and compound S9 oxalate using NMR and electrophoretic mobility shift analysis (EMSA), and (III) prediction of binding conformation and interactions between FOXO3 DBD and...
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Leachability of Ba and Cr from alkali-activated matrices
Cába, Vladislav ; Hajzler, Jan (referee) ; Koplík, Jan (advisor)
The aim of this work is to determine the usability of alkaline activated matrices made from ashes to inhibition of barium and chrome. Ashes – fly ashes and ashes from fluidized bed combustion – were compared with cement used for inhibition. By using inductively coupled plasma atomic emmission spectrometer were determined concentrations of barium and chrome in leachates based on norm ČSN EN – 12457-4. In addition, images were taken on the scanning electron microscope and crystallographic spectra from X-ray crystalography were obtained to determine structure. The results show that ashes from fluidized bed combustion are suitable for inhibition of both barium and chrome, whereas fly ashes can not sustain these elements with such success.
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Effect of selected food supplements on metabolism of food-born carcinogens
Fousová, Petra
The consumption of dietary supplements such as flavonoids may reduce risk of many civilization diseases. Flavonoids are able to modulate the activity of cytochromes P450 (CYPs), xenobiotic-metabolising phase I enzymes of biotransformation that are involved in the activation and detoxification of food-derived carcinogens. Inhibition of CYP activities by flavonoids has been extensively studied because of their potential use as agents blocking the initiation stage of carcinogenesis. On the other hand, flavonoids have been shown to enhance the activation of carcinogens and/or influence their metabolism via induction of specific CYPs. In the first part of this study, flavonoids dihydromyricetin and α-napthoflavone were explored for their possible effects on CYP1A1 expression and activity when administered in combination with carcinogen benzo[a]pyrene (BaP). For this purpose, liver, small intestine and colon microsomal fractions were isolated from treated rats and induction of CYP1A1 was evaluated by immunodetection and EROD activity measurements. In liver and small intestine, all combinations of BaP and flavonoids led to strong induction of CYP1A1 expression. Moreover, the CYP1A1 protein levels were almost identical to levels observed when the rats were treated with BaP alone. However, in comparison...
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Study of selected flavonoids as modulators of cytochrome P450 3A4
Skotnicová, Aneta ; Hodek, Petr (advisor) ; Koblihová, Jitka (referee)
Flavonoids are secondary metabolites of plants exhibiting a wide range of biological activities. Special attention is paid to them mainly because of their antioxidant properties. Consumption of these natural substances is currently increasing especially in the form of dietary supplements. In addition, these compounds exhibit antiviral, anti-inflammatory or hepatoprotective effects and some of them also exhibit mutagenic and/or pro-oxidative properties. The study of flavonoid interactions with biotransformation enzymes such as cytochromes P450 are important because of their possible interference with the metabolism of drugs or carcinogenesis processes. In this bachelor thesis the influence of selected flavonoid compounds, dihydromyricetin and myricetin, on the expression and activity of cytochrome P450 3A4 was studied. The flavonoid premedication of rats did not resulted in induction of CYP3A4. However, dihydromyricetin and myricetin inhibit CYP3A4. IC50 were determined as 25 M for dihydromyricetin and 24 M for myricetin. Key words: Immunodetection, HPLC, inhibition, induction (In Czech)
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Použití nasycených vyšších mastných kyselin v technologii vína
Budínová, Dagmar
This thesis was focused on finding a methods which are able to reduce the doses of sulfur dioxide in the wine industry. The first part of the work was focused on sulfur dioxide, it is unique properties and also the negative impacts on the wine. Sulfur dioxide and all its forms were described in the work. In work we can find a real methods of sulfur dioxide which can be used in wine practice. In the second part the chemical additives are described. Chemical additives can serve as a complement or fully replacement SO2 in wine technology. Higher saturated fatty acids can serve as a complement to the sulfur dioxide. Higher saturated fatty acids are studied in detail in this work. The main essence of the work was processing experiment, which studied different doses of higher fatty acids to wine. It was monitoring the next evolution of sulfur dioxide in wine. All the doses of sulfur dioxide and higher saturated fatty are evaluated. Based on evaluation you can find a recommendations of using higher saturated fatty acids for practice and follow-up research.
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Analýza toxicity průsakových vod ze skládky odpadů Kuchyňky
Staňková, Jiřina
The thesis is focused on analysis of the toxicity of the water seepage from landfill Kuchyňka. It is composed of theoretical part, which is engaged in waste management and its disposal. Then it is engaged in the process of landfill directed at water monitoring. The next part introduce into basic methods of ecotoxicology. The practical part of thesis is engaged in analysis of the water seepage and rainwater from landfill Kuchyňka. Those were tested and on semichronacal toxicity with seeds of white mustard (Sinapis alba, L.). Thesis contains a description of this method, used materials and operating procedure. Then the results of the tests are summarized and evaluated. In results there are values of root growth inhibition and seed germination capacity in individual phases of test that are graphically presented. Thesis is supplemented with photographs of landfill and interpretation of test of toxicity.
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Preparation of mutated forms of fosfatidylinositol kinase IIα
Gregor, Jiří ; Šulc, Miroslav (advisor) ; Košek, Dalibor (referee)
Phosphatidylinositol 4-kinases (PI4K) are enzymes that form phosphatidylinositol-4- phosphate, which is an important regulatory molecule and precursor for the synthesis of other regulatory molecules. PI4K are interesting from medical aspect, because of connection between their function and viral, malignant, metabolic and neurodegenerative diseases. PI4K type II are inhibited by calcium cations, whereas PI4K type III aren't. The goal of this thesis was to elucidate the relationship between structure and regulation of function of PI4K IIα, specifically regulation by calcium cations. We failed in preparation of mutated forms of PI4K IIα that wouldn't be inhibited by calcium cations. However, the results obtained suggest, how aminoacids N313, D346 and E193 affect the kinase activity of PI4K IIα. (In Czech)
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Self-control: disentanling inhibition and initiation
Kucharský, Šimon ; Vranka, Marek (advisor) ; Lukavský, Jiří (referee)
Self-control is usually defined as a unit in a regulatory cycle process. As such, it can be used for inhibition of urgent need or overriding impulsive responses, but it can also mean that person can engage in a behavior which is aversive at the moment. Contemporary the most influential is strength model of self-control that envisages one general and limited source of energy for every act of self-control. According to this model, after depleting this energy, one's ability to control his or her behavior or thought is impaired, even in domains that does not relate to the cause of the depletion. However, there has been substantial criticism of this model recently - regarding theoretical implausibility, possible bias in literature (or even manipulated results) and also growing body of evidence that is not in line with the model. Because of that, there are attempts to alter or dismiss the model. One of the possible updates is distinguishing between two domains of self-control (inhibition and initiation). This thesis overviews body of recent findings about self-control and proposes experimental design which could serve to verify hypothesis of existence of two independent domain of self- control. Limits of this approach and suggestions for future research are also discussed. Keywords: Self-control, ego...
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Succession of insect communities inhabiting carcasses of small vertebrates, with emphasis on the beetles
Kadlec, Jakub ; Šípek, Petr (advisor) ; Růžička, Jan (referee)
This master thesis deals with succession and succession mechanisms of beetles (Coleoptera) on carrions of small vertebrates. As a model sample of small carrion a small mouse of weight 20 grams was chosen. In 2014 two experiments occurred. The first one studied the succession of a beetle community in dependence on seasonality and time of death of the sample. The second experiment was aimed to survey the blocking effect of an early insect succession on the final beetle community composition on carrions. It turned out, that during decomposition of the carrion the overall amount of beetles raised equally to the guild of necrophagous beetles. Change of the species spectrum during succession was not statistically confirmed. On the other hand, the effect of seasonality was clear as during the season the abundance and the amount of species increased. The proportion of trophic guilds changed significantly, necrophagous beetles were the most dominant part of the community towards the end of the season. Equally, the taxonomic composition of the community also changed during the season. The seasonal dynamics of carrion beetles was clear; Nicrophorus vespillo (Linnaeus, 1758) and N. investigator Zetterstedt, 1824 showed their peaks in spring and summer while N. humator (Gleditsch, 1767) and N. vespilloides...
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