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Mining novel terpene synthases from large-scale repositories
Čalounová, Tereza ; Pluskal, Tomáš (advisor) ; Štáfková, Jitka (referee)
Terpenes and terpenoids represent the largest and most structurally diverse group of natural products, with applications across many fields, including the pharmaceutical industry. These molecules are synthesized in nature by enzymes known as terpene synthases. This thesis conducted a bioinformatic analysis of a curated database containing all 1125 experimentally characterized terpene synthases, focusing on identifying patterns in sequence lengths and domain architectures of these enzymes across different kingdoms of life. Based on this analysis's knowledge, sequence-guided mining was conducted to identify possible new terpene synthases. Using nearly 5.5 billion protein sequences from various large-scale sequence repositories, the mining resulted in the identification of more than 600 thousand putative terpene synthases. These putative terpene synthases mainly originate from Bacteria and metagenomes, sources that had historically been less explored. The resulting dataset, accompanied by a phylogenetic tree, sequence similarity network, and two prioritization scores, offers a valuable resource for the discovery of novel terpenes. Keywords: terpene synthase, TPS, mining, Pfam, SUPERFAMILY, domain, terpene
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Odors attractive to sand flies and mosquitoes
Strejc, Vojtěch ; Volf, Petr (advisor) ; Štáfková, Jitka (referee)
This thesis focuses on the odour signals used by blood-sucking insects to locate their hosts. It focuses mainly on phlebotominae sand flies, but also deal with the most important findings published for mosquitoes, which are close relatives of sand flies. In addition to sex pheromones, odor signals important to sand flies include carbon dioxide, higher alcohols, aldehydes, alkanes, ketones, and lactic acid. Sand flies and mosquitoes are also attracted to plant kairomones, such as terpenes, because they obtain their sugar meal from plants. In humans, it is known that various individuals are differently attractive to mosquitoes, this individual variability is mainly due to the skin microbiome. In sand flies, significantly different attractivity to Lutzomyia longipalpis was described among six volunteers. Part of this thesis focuses on the increased attractiveness of infected hosts for vectors (mosquitoes and sand flies). Mosquitoes of the genus Anopheles were in some studies more attracted to humans infected with Plasmodium falciparum, specifically those individuals who had gametocytes in their blood. Plasmodium falciparum apparently affect the vector in host selection by altering the odor of the host's sweat or breath to make it more attractive to mosquitoes. Similarly, sand flies are more attracted...
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Copper metabolism in Trypanosoma brucei
Sandner, Bruno ; Mach, Jan (advisor) ; Štáfková, Jitka (referee)
Copper serves as a cofactor for many important enzymes due to its redox properties. However, the presence of free copper ions in the cell can lead to undesired effects such as protein aggregation and loss of iron-sulfur clusters, ultimately resulting in cell death. Therefore, the intracellular concentration of copper in parasitic organisms is strictly controlled. Copper metabolism in parasitic organisms is not well understood, hence this work focuses on Trypanosoma brucei, the causative agent of sleeping sickness and the disease in cattle called nagana. The aim of this thesis was to investigate how copper is transported in the cell and to test its toxicity in T. brucei. Understanding copper transport in the cell could lead to the development of drugs disrupting copper homeostasis and exploit of its toxic properties. In this diploma thesis, the function of the P1B-type ATPase of T. brucei in copper transport was described based on functional complementation. Successfully, the expression of the P1B-type ATPase was reduced using RNAinterference in T. brucei. The decreased expression of this transporter led to increased sensitivity to copper, indicating its role in copper detoxification. Furthermore, we demonstrated the higher resistance to copper and its increased requirement in the metabolism of the...
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Characterization of polar tube proteins of microsporidia.
Satrapová, Alexandra ; Doležal, Pavel (advisor) ; Štáfková, Jitka (referee)
Microsporidia is a group of intracellular parasites belonging to Fungi. Even though this group seems to be diverse with great variety of hosts and infected tissues they share completely unique invasion apparatus. A key organelle of this apparatus called the polar tube serves as a conduit for sporoplasm passage into the host cell. It consists of PTP proteins which are the main interest of this diploma thesis. Major effort was devoted to the study of the two main PTP proteins. In contrast to already published data, we were unable to verify the interaction of PTP proteins using a yeast two-hybrid system. On the contrary, experiments with in vitro prepared proteins have shown the possible formation of homopolymeric complexes of PTP2 and PTP3 proteins from Nosema bombycis (NbPTP2, NbPTP3). Several constructs were prepared for the expression of recombinant NbPTP2 and NbPTP3 proteins in Escherichia coli. Expression of NbPTP2 was successful but under native conditions the protein wasn't obtained in soluble fraction allowing its subsequent purification. The preparation of recombinant NbPTP3 was complicated by the rapid formation of presumably degradation products. Therefore, a final construct was made to allow purification of intact NbPTP3 using two purification tags at the N- and C-termini of the protein....
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The invasion apparatus of protozoan parasites
Novotná, Veronika ; Petrů, Markéta (advisor) ; Štáfková, Jitka (referee)
Protozoa parasitism has evolved many times independently in the history of eukaryotes. Some organelles were reduced, and specific invasion apparatuses were developed by adapting to the host. These apparatuses help to penetrate host cells and escape the immune system. The thesis summarizes the findings of the invasion apparatus and invasion of four selected unicellular protozoan parasites of genus Plasmodium, Microsporidia, Ichthyobodo and Rozella. Each chapter includes general knowledge of the parasite, its structure and life cycle. Keywords: Apicomplexa, Plasmodium, Microsporidia, Ichthyobodo, Rozella, merozoite, glideosom, moving junction, polar tube, germination, cytostome, zoospore, germ tube;
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Exosomes in parasitic protists
Horáčková, Jana ; Tachezy, Jan (advisor) ; Štáfková, Jitka (referee)
Most cells release extracellular vesicles. These vesicles are exosomes, ectosomes and apoptotic bodies. The main function of ectosomes and exosomes is the intracellular communication and transport of molecules between cells. The goal of this bachelor thesis is to review the current knowledge about exosomes and ectosomes and how these vesicles contribute to the pathogenicity of parasitic protists. The parasitic protists release exosomes and ectosomes that contribute to their development in the host and play a key role in their pathogenicity. Exosomes and ectosomes can also affect the immune system of the host and facilitate the invasion of parasitic protists into the host cells.
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Parasite's life within the host cell.
Krupičková, Alžběta ; Doležal, Pavel (advisor) ; Štáfková, Jitka (referee)
Plasmodium falciparum is one of the most dangerous human intracellular single-celled pathogen. This thesis describes the invasion, the survival and the egress of the pathogen from the host cell (erythrocyte). The main topic of the thesis is the parasite's life within the host cell in a newly created compartment, parasitophorous vacuole. By exploding hundreds of proteins Plasmodium falciparum establishes number of unique modifications inside as well as on the surface of the host cell. The thesis finishes with the chapter on the therapy and possible development of new drugs and the chapter on the parasite evolution. Powered by TCPDF (www.tcpdf.org)
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Host immune response in neuroinfections caused by parasitic helminths.
Macháček, Tomáš ; Panská, Lucie (advisor) ; Štáfková, Jitka (referee)
Among helmiths, there are some parasites which may dwell in the central nervous system of humans during their ontogenic development. Contrary to the former concept of so called immune privilege of this site, hosts develop the immune response against them. Both immune cells and resident immunocompetent cells (astrocytes, microglia) participate in these immune reactions. The host immune response consists of cellular as well as humoral immunity. This bachelor's thesis gives the general features of the immune response in the central nervous system and describes the immune response during particular helminthic neuroinfections: neuroschistosomiasis, neurocysticercosis and neurotoxocarosis.
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Phlebotomine saliva: the perspecives of application of some of their recombinantly produced proteins
Rožníčková, Lucie ; Zídková, Lenka (advisor) ; Štáfková, Jitka (referee)
Sandflies (Diptera: Phlebotominae) are the vectors of one of the most significant tropical diseases, leishmaniosis. Their saliva contains substances with antihemostatic, vasodilatory and immunomodulatory effect. These substances are of great significance in transmission of leishmaniosis, because of their ability to influence the host immune response. Naive host saliva modulate the immune system to such an extent, that it reduces an infective dose and increases the pathogenicity of leishmaniosis. On the other hand, a repeatedly exposed host generates a cellular and antibody immune response, which is able to make the initial development of infection impossible. Repeated exposure of individual sandflies lead to formation of antibodies against components of saliva, which may play a role as a rate exposure indicator and thus the risk of leashmaniosis infection. These proteins and glycoproteins can be produced by recombinant DNA technology. Recombinant vaccine could help in the fight against leishmaniasis. Keywords: saliva, sand fly, leishmania, recombinant proteins.
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