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Influence of natural polyphenolic substances on p53 protein expression
Bušanski, Patrik ; Němcová, Andrea (referee) ; Brázda, Václav (advisor)
The tumor suppressor protein p53 is one of the major regulators of the cell cycle after DNA damage. In addition to stopping the cycle and repairing DNA, it can, in extreme cases, induce programmed cell death - apoptosis. Mutations in the gene encoding p53 are present in more than 50% of cancer cases. This thesis examines alternative natural polyphenolic substances that could increase the level and expression of p53 protein in tumor cells. These substances could be an alternative to non-specific cytostatics, which bring many undesirable additional effects during treatment. In the theoretical part of the thesis the structure and properties of the p53 protein and describes alternative therapeutic approaches with a focus on polyphenolic substances is explained. The aim of the experimental part was to determine the effect of curcumin and resveratrol in comparison with often used cytostatic drug, doxorubicin, on cell viability of tumor cells and on p53 protein levels. The effect of these substances on the binding of p53 to DNA in yeast systems was also examined. It was found that doxorubin efficiency is many times higher than the examined polyphenolic agents, but resveratrol was showing some potential as a suitable alternative in the treatment of tumors, thanks to the ability to activate apotosis. It was clearly demonstrated that there is an association between induced programmed death and increased p53 protein expression after resveratrol treatment.
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Use of some molecular techniques to metabolic characterization of industrially significant yeasts
Kostovová, Iveta ; Brázda, Václav (referee) ; Kráčmar, Stanislav (referee) ; Márová, Ivana (advisor)
Karotenoidy, ergosterol a mastné kyseliny jsou velmi žádané látky využívané v krmivářském, potravinářském a kosmetickém průmyslu. Konvenční zdroje mastných kyselin a karotenoidů jsou závislé na sezónních podmínkách, geografické poloze a na dostupnosti zemědělské půdy, což znesnadňuje pokrýt jejich neustále se zvyšující spotřebu. Velmi slibným řešením je mikrobiální produkce výše uvedených látek pomocí karotenogenních kvasinek, které jsou schopny simultánně produkovat karotenoidy, mastné kyseliny i ergosterol. Předložená disertační práce je zaměřená na molekulární a metabolickou charakterizaci karotenogenních kvasinek a na jejich potenciál pro průmyslové aplikace. Proto první experimentální části práce jsou zaměřeny na kvasinky druhu R. mucilaginosa a R. toruloides, jejich produkční vlastnosti, vliv nutričního stresu a různých zdrojů uhlíku, jakými byly xylóza a glycerol. Kromě podrobné charakterizace jejich produkčních vlastností, byly tyto kmeny také charakterizovány molekulárními metodami, zahrnující sekvenční analýzu ITS1, ITS2 a D1/2 ribozomálního operonu a analýzu mini a mikrosatelitních sekvencí M13 a GTG5. Druh R. toruloides je známý jako vynikající producent mastných kyselin, a proto se v poslední době stal cílovou karotenogenní kvasinkou pro vývoj nástrojů pro jeho genetickou manipulaci. V této práci byly úspěšně připraveny geneticky modifikované klony kmene R. toruloides, nesoucí nadměrně exprimované geny pro diacylglycerol acyltransferázu (DGA1) a glycerol-3-fosfát dehydrogenázu (GPD1). Produkce mastných kyselin u modifikovaných klonů nebyla ve srovnání s původním kmenem vyšší. Proto byla další část práce zaměřená na přípravu nadprodukčních mutantních kmenů připravených náhodnou mutagenezí. Kombinace limitace dusíkem a inhibice produkce karotenoidů vedla k úspěšné selekci robustních mutantních kmenů s nadprodukcí karotenoidů vykazující rezistenci vůči difenylaminu. Poslední část práce se zabývá produkčními vlastnostmi méně známých druhů karotenogenních kvasinek náležící do řádů Sporidiobolales a Cystofilobasidales, ve srovnání s relativně dobře prostudovanými karotenogenními druhy R. toruloides a P.rhodozyma. V této studii byly nejlešími producenty mastných kyselin kmeny S.metaroseus CCY 19-6-20 a C. macerans CCY 10-01-02. Nejlepší producent karotenoidů, kmen R. mucilaginosa CCY 19-04-06, navíc produkoval lykopen, který představoval více než 80 % celkového množství karotenoidů produkovaných tímto kmenem.
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Analyses of inverted repeats in human patogen genomes
Hanzlíková, Anna ; Nováčková, Ivana (referee) ; Brázda, Václav (advisor)
Pathogens are organisms that cause various host diseases. These include prions, viruses, bacteria, fungi, protozoa and animals. This bachelor thesis is focused specifically on viruses causing human diseases such as severe respiratory syndromes, liver diseases or cervical cancer. The aim of this bachelor thesis was to characterize the presence and location of inverted repeats in the genomes of organism using the web application Palindrome analyzer. Four viruses were selected, two of them are from the group of DNA viruses and two from the group of RNA viruses. In view of the outbreak of a pandemic in early 2020 caused by virus SARSCoV-2, is included in this bachelor thesis. Thus, SARS-CoV and SARS-CoV-2 were selected from RNA viruses and hepatitis B virus and human papillomavirus were selected from the DNA viruses. The sequences of the viral genomes were obtained from the NCBI (National Center for Biotechnology) database. Then, all four viruses were analyzed for the presence of inverse repeats, their location and size using the Palindrome analyzer, which is available online. The largest genome was SARS-CoV-2 of 29 903 bp, which also had the most inverse repeats.
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Analysis of C. necator genome changes after evolutionary adaptation
Kroupa, Štěpán ; Obruča, Stanislav (referee) ; Brázda, Václav (advisor)
This bachelor’s thesis deals with analysis of mutations in bacterial populations of Cupriavidus necator H16 evolved in distinct stress conditions. This analysis was performed by processing data from the genome sequencing method „Next Generation Sequencing“, outsourced through the company DNALink. A list of mutations for each adapted population was constructed through bioinformatic methods. These mutations were then associated with specific areas of the reference Cupriavidus necator H16 genome from NCBI and analysed according to available information. Finally, the effect of these mutations on production of storage polymers polyhydroxyalkanoates was discussed.
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Aflatoxins in food and their influence on DNA and cell lines
Šislerová, Lucie ; Pernicová, Iva (referee) ; Brázda, Václav (advisor)
Aflatoxins present a great danger due to their high toxicity and carcinogenicity, which is not easily avoided in everyday life. Intoxication with aflatoxins causes a wide range of diseases ranging from mild diseases to organs necrosis or death. Aflatoxins mostly affect the liver, where it degrades and the formation of subsequent metabolites, which are the most toxic to the body. For this reason, their precise determination and understanding of the principle of their effect is very important. In this work, methods for monitoring and closer determination of aflatoxin effects on human cells were calibrated. The methods that were used are: MTT viability assays, fluorescence microscopy and flow cytometry. Next, the amount of aflatoxins present in different foods with different storage conditions was measured. For this analysis were used ELISA assays RIDASCREEN Aflatoxin Total and RIDA Aflatoxin column. Calibrated methods were compared with the methods already used to determine the effect of aflatoxins and the results of the ELISA tests were compared with the limits of aflatoxin levels permitted by the Czech legislation. None of the controlled foods contained above-the-limit concentration of aflatoxins, which in the Czech Republic is set at 4-10 µg/l (varies for different types of food). Foods that were poorly stored but not visibly affected by fungi showed the highest levels of aflatoxins. The LD50 value for aflatoxin B1 was determined to 12,25 µM. The type of cell death caused by aflatoxins was determined by flow cytometry and these data were further confirmed by fluorescence microscopy images.
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Analysis of C. necator genome changes after evolutionary adaptation
Vojsovič, Matúš ; Šedrlová, Zuzana (referee) ; Brázda, Václav (advisor)
The p53 protein is a transcription factor that belongs to the group of the tumour suppressor proteins. p53 functions include cell cycle regulation, interaction with DNA, and responses to damaged DNA that may lead to apoptosis or even senescence may occur. The theoretical part summarizes the latest information about the chemical structure and functions of the protein p53 and allosteric modifications that the p53 protein may possess in cells. It also describes selected methods of isolation and characterizes proteins. The aim of the experimental part was to isolate and characterize -isoforms of the p53 protein, which were isolated from the microorganism E.coli. Protein production was preceded by preparation and transformation of plasmids into production cells. From the production cells, 4 -isoforms of p53 were isolated by affinity chromatography, due to the polyhistidine anchor that the proteins contain. The isolated proteins were subsequently characterized by SDS-PAGE and western blotting. Moreover, the transactivation potential in the yeast system was monitored by luciferase assay under conditions involving the use of various culture media, as well as expressed or coexpressed under the inducible GAL1 promoter and the constitutive GPD promoter.
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Molecular characterization of selected PHA producers
Kubáčková, Eliška ; Brázda, Václav (referee) ; Obruča, Stanislav (advisor)
This diploma thesis focuses on the molecular characterization of selected PHA producers. Within this work, the PHA producing thermophilic isolates originating from the samples of activated sludge and compost were identified and characterized using molecular biological methods. By sequencing the 16S rRNA gene, the thermophilic isolates were identified and taxonomically classified into the Firmicutes bacterial phylum. In these bacterial isolates, the ability to produce PHA at the genotype level was determined by conventional PCR detection of the phaC gene encoding PHA synthase, which is a key enzyme in PHA biosynthesis. Class I, II and IV PHA synthases were detected in most of the isolated bacteria, wherein class I and II PHA synthases are not characteristic for these bacterial genera. The largest proportion of isolates was identified for the species of thermophilic bacterium Aneurinibacillus thermoaerophilus, in which class IV PHA synthase was detected. In the second part of the diploma thesis, the RT-qPCR method was implemented to study the expression of selected genes of the bacterium Cupriavidus necator H16 involved in PHA metabolism. As part of the implementation of this method, PCR-based detection of selected genes was optimized and quantification of genes using real-time PCR was performed. The tested method included steps of RNA isolation, cDNA synthesis and quantification of gene segments for which the critical points of the method were determined based on the obtained data.
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Optimization of p53 mutant protein isolation and its DNA binding properties
Osadchuk, Olha ; Zemanová, Jana (referee) ; Brázda, Václav (advisor)
Protein p53 je jednou z nejdůležitějších molekul v lidském těle. P53 reguluje celou řadu procesů v buňce, jako je například oprava DNA, buněčný cyklus nebo indukce apoptózy. Protein p53 je známý i jako „strážce genomu“. DNA vazebné schopnosti proteinu p53 jsou důležité pro normální vývoj a růst buňky. Mutace genu pro p53 mohou vést ke ztrátě jeho DNA vazebných vlastností a funkce nádorového supresoru, což muže způsobit rozvoj rakoviny. Teoretická část této diplomové práce je zaměřena na popis vlastností, funkce a mechanismus aktivace proteinu p53 a popis lokálních sekundárních struktur DNA. Hlavním cílem experimentální části byla produkce čtyř mutantních forem proteinů p53 a wild-type p53 proteinu a studium jejich vazebných vlastnosti s různými lokálními sekundárními strukturami DNA. Pomoci Gateway klonovacího systému byly připraveny čtyři expresní vektory, které byly použity pro produkci proteinů v bakteriálním expresním systému. Celkem byly úspěšně připraveny čtyři mutantní formy a wild-type p53 protein. Jejich vazebné vlastnosti byly studovány gelovou retardační analýzu. Výsledky naznačují různé DNA-vazebné vlastnosti wild-type p53 a studovaných mutantních forem tohoto proteinu. Všechny mutantní proteiny ztratily schopnost sekvenčně specificky vázat DNA, zatímco nespecifická interakce s DNA byla pozorována u tří ze čtyř mutantních forem. Jeden ze studovaných mutantních proteinů se vázal jenom na superhelikální formu DNA.
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DNA Isolation and Analysis Focused on Microorganisms Important in Food Production
Čutová, Michaela ; Obruča, Stanislav (referee) ; Fojtová,, Miloslava (referee) ; Brázda, Václav (advisor)
Identification of bacterial DNA consists from several steps: cell lysis, isolation and purification of DNA, precipitation by ethanol, identification of bacterial strain by PCR or other molecular biology methods. Each step must be optimised. Nucleic acids can be isolated from cells using magnetic particles. The molecules of DNA are bound to the surface of magnetic carriers by electrostatic interaction, and then they are eluted into buffer. The aim of the work will be to optimize individual steps of identification of bacterial DNA: cell lysis, DNA isolation, characterization of solid magnetic carriers functionalized by amino groups for nucleic acids isolation. The presence of DNA will be verified using agarose gel electrophoresis and the amount of eluted DNA will be determined spectrophotometrically. The quality of isolated DNA will be proved by their amplification using polymerase chain reaction (PCR). Furthermore, the thesis focuses on the study of secondary structures of nucleic acids – cruciforms structures and quadruplexes. These structures are involved in the regulation of cellular processes and their appearance is associated with cancer development and neurodegenerative diseases. In silico genome analysis was performed on important food industry microorganisms. The microorganisms genomic sequences were obtained from the NCBI (National Center for Biotechnology) database. The Palindrome Analyzer and G4 Hunter software were used for the analysis.
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Comparison of biotechnological procedures for pure proteins preparation
Bušanski, Patrik ; Langová, Denisa (referee) ; Brázda, Václav (advisor)
The production of recombinant proteins is a biotechnological process during which proteins are produced in foreign organisms by gen manipulation. To form a recombinant plasmid the gene encoding the desired protein is isolated and inserted into an expression vector. The plasmid is then transformed using physical or chemical method into a suitable host, where the recombinant gene is translated into amino acid sequence in the newly synthetized protein. The theoretical part of this bachelor thesis includes characteristics of proteins, methods of recombinant protein preparation and compares individual expression systems. Three isoforms of the p53 protein, which were synthesized in the E. coli microorganism, were selected for processing the experimental part. The transformed recombinant plasmid contained two tags for purification, HIS-tag and GST-tag, making it possible to compare the efficacy of the two purification methods. HIS-tag purification was found to work for all three isoforms better, with concentrations of recombinant proteins were several times higher than those of the GST-tag. The p53 proteins are about 50 kDa long, what was confirmed by sodium dodecyl sulfate polyacrylamide gel electrophoresis.
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