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One of the key components of the innate immune system are natural killer (NK) cells. The task of these cells is to induce apoptosis in target cells (e.g., cancer or virally infected cells). The target cells are identified by their interaction with surface receptors of the NK cells. On the surface of the NK cells, there are activating and inhibiting receptors. One of the activating receptors is the natural cytotoxicity receptor NKp46. Several ligands of this receptor have been identified, one of them being the epithelial adhesin Epa1 of yeast Candida glabrata. The invasive candidiasis caused by this yeast is a feared complication for patients with haematological diseases. The use of the NK cells in immunotherapy includes bispecific fusion proteins which can bind to the NK receptor with one part and to tumour antigen with the other part. This work focuses on recombinant preparation of the NKp46 protein. To facilitate a study of the effects of O-glycosylation on the binding of the ligands, a mutation of the glycosylation site NKp46 T225A was prepared. A stably transfected HEK293S GnTI- and HEK293T cells had been prepared and these proteins were then extracellularly secreted. The Epa1 protein had been produced in E. coli bacterial expression system and purified. The binding ability of the Epa1 protein...

Liver flukes of the family Fasciolidae are parasites of mammals including human. Fascioloides magna and Fasciola hepatica are considered as a veterinary and medically important species occurring also in the Czech Republic. Fascioloides magna and F. hepatica infect wide spectrum of wild and domestic ruminants and in case of F. hepatica human can be also infected. Both flukes are responsible for damage of liver tissue and/or bile-ducts of their definitive hosts causing weight lose, anemia, reduced productivity and in specific cases the death of the host. Effective diagnosis plays the key role in control of F. hepatica and F. magna infections. Current diagnostics is predominantly based on serodiagnostic methods using specific antigens e.g. from excretory-secretory products (ESPs). Due to heterogenity of ESPs, such diagnostic markers can lack the specificity and also the reproducibility of the method is poor. Particular proteins of ESPs are often used in diagnostics of fasciolid flukes. Such approach requires biological material and laboratory procedures associated with identification, purification and antigenicity testing of selected proteins. Recent development of parallel sequencing technologies results in huge amount of genomic, transcriptomic and proteomic data, which are publicly available. Such...

The Type I restriction-modification enzyme EcoR124 is a pentameric complex consisting of one specificity subunit, two methylation subunits and two motor subunits (HsdR) that can recognize specific DNA sequences and perform double-stranded DNA cleavage and modification. The HsdR subunit is responsible for ATP-dependent DNA translocation and DNA cleavage. Even though the first crystal structure of HsdR was obtained ten years ago, a large part of the C-terminus has not been resolved in any HsdR structures to date. This dissertation aims to elucidate its role within the HsdR subunit and the whole pentameric complex by solving the structure of the C-terminus by means of X-ray diffraction crystallography and explore its function using biochemical, microbiological, bioinformatical and computational methods.

Aim of the thesis was optimization of production of monoclonal antibody against interleu-kin 2 (IL 2) as fusion construct with IL 2 by preparation of new expression vectors based on pTW5 plasmid and by replacing the native signal sequence with new one, originally from secreted alkaline phosphatase. This fusion antibody has interesting biological activity with therapeutic potential - prolonging the half-life of IL 2 in blood circulation. (The thesis is written in Czech.) Powered by TCPDF (www.tcpdf.org)

Drosophila melanogaster is a widely used model organism in genetic research and in a number of other disciplines associated with medical and biotechnological issues. The first part of this thesis presents a review of some basic genetic tools and gene expression reporters used in D. melanogaster research with emphasis on the use of GFP reporter. The second part presents a description and results of my experimental work aimed at the reporter construct consisting of adenosine deaminase gene (ADGF-A) and GFP marker. When using gene expression reporters such as GFP, it is important to know whether the presence of reporter does not affect the studied process. The experiment described in this study tested whether the fusion protein consisting of GFP and adenosine deaminase is fully functional enzyme or whether the enzyme activity is influenced by the presence of fluorescent tag. Results of this work support the usefulness of using the fusion construct as a gene expression reporter.

Ferrochelatase (FeCH) is an ubiquitous enzyme producing heme, an essential pigment for all forms of organisms. In photosynthetic organism, heme is synthesized together with the chlorophyll in one branched pathway and the FeCH enzyme appears to be important for regulation of both the chlorophyll and the heme biosynthesis. To understand regulatory role of this protein, an active recombinant FeCH from photosynthetic organism would be invaluable. The aim of this project is to express FeCH from cyanobacterium Synechocystis 6803 in Escherichia coli and to prepare a protocol for the purification of this protein as a highly active enzyme.