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Characterisation of recombinant cathepsins B of the bird schistosome Trichobilharzia regenti
Dvořáková, Hana ; Mikeš, Libor (advisor) ; Dvořák, Jan (referee)
This study focuses on the recombinant cysteine peptidases - cathepsin B originating in the bird schistosome Trichobilharzia regenti that is unique across the whole family for its ability to migrate through the nerve tissue to the final localization. For invasion, migration, degradation of nutritional proteins and/or evasion of host immune responses, schistosome employs peptidases. This study follows the research done by researchers of Department of parasitology, Faculty of Natural Sciences, Charles University. The main goal of this study was to deepen the characteristics of recombinant cathepsins B originating in T. regenti. In T. regenti, two cysteine peptidases - cathepsins B1 (TrCB1) and B2 (TrCB2) - have been previously characterized. TrCB1 is located in the gut of schistosomula and involved in digestion. TrCB2 occurs in post-acetabular penetration glands of cercariae and probably facilitates penetration. The recombinant pro-cathepsin B (isoforms TrCB1.1, TrCB1.4 and also TrCB2) were expressed in Pichia pastoris yeast system. An attempt was made to produce in P. pastoris the recombinant isoform TrCB1.6, in which the active site cysteine is substituted by glycine. While TrCB2 underwent self-processing in the expression medium, TrCB1.1 and TrC1.4 zymogens were effectively activated only after the...
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Purification of recombinant proteins by affinity chromatography
Zemek, Ondřej ; Mácha, Jaroslav (advisor) ; Hrdý, Ivan (referee)
The isolation and purification of recombinant proteins is essential for further study of their structural and functional properties. The affinity chromatography is usually the method of choice for this task. In this paper the most used affinity tags are reviewed for their properties and experience with their application. The tags covered here include CBP, MBP, GST, polyhistidine and polyarginine tags, FLAG-tag, Strep-tag II and SpA. The origin and properties of the tags, their influence on form and localization of fusion protein as well as binding, elution and removal are discussed. Keywords: affinity chromatography, recombinant protein, purification, affinity tag
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Application of tissue culture test plates for production of recombinant protein in HEK293 cells; determination of optimal conditions
Krzyžanková, Marcela ; Španová, Alena (referee) ; Ševčík, Mojmír (advisor)
Efficient production of the recombinant proteins (r-proteins) must be based on previous testing of an expression of a small amount of the r-proteins. This work focuses on optimizing the expression of the r-proteins in 12-well plates. It includes testing of an appropriate speed of shaking, production and transfection volume. It compares all the current testing vessels (it compares a 50-ml centrifugation tube to new tested plates that can substitute the unsuitable tubes). It also compares these new tested plates to production square bottles in order to compare the r-protein expression in the plates to the r-protein expression in the bottles. It monitors effects of carbon dioxide on a number of vital cells, their viability, a relative frequency of positive cells on GFP in various cultivation vessels (plates, tubes, bottles), and pH of HEK 293 cellular cultivation during the 4-day cultivation process as well. On the basis of the results and statistical processing of the results, we have set the optimal agitation speed of 230 rpm for the 12-well plates. We have also set the appropriate production and transfection volume of 2 and 0.5 ml for the 12-well plates. In order to evaluate variables and compare cultivations in all the vessels, the tubes could be substituted by the plates. There is a statistically significant impact of carbon dioxide on the number of cells, their variability, relative frequency of cells (positive on GFP) and pH of the cellular HEK 293 cultivation in the cultivation vessels. There is the strongest r-protein expression in carbon dioxide conditions. The results of this work allow to employ the 12-well plates when we aim to test the expression of the r-proteins in a small amount and in carbon dioxide conditions. On the basis of the findings, the expression of the r-proteins in the 12-well plates and carbon dioxide conditions can substitute the expression of the r-proteins in the production bottle and in carbon dioxide free conditions.
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Transient transfection of a serum free cell culture using polyethyleneimines
Čutová, Michaela ; Španová, Alena (referee) ; Ševčík, Mojmír (advisor)
Master’s thesis deals with the transient transfection of the serum free animal cell culture using polyethyleneimines. In the theoretical part formation of recombinant DNA molecules, used expresion vectores, used DNA transfer and detection of recombinant proteins are discussed. The experimental part deals with efficiency of the polyethylenimine mediated transient transfection under various experimental conditions. 293HEK/EBNA cell line was chosen as an experimental model. First the most effective plasmide - pCEP4/SEAP was selected. Then three transfection methodes were tested: Muller (2005), Durocher et al. (2007) and Backliwal et al. (2008). The highest recombinant protein expresion was reached using the method of Backliwal et al. (2008).
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Impact of cell density on transient transfection of HEK293 cells culture.
Krzyžanková, Marcela ; Španová, Alena (referee) ; Ševčík, Mojmír (advisor)
Recombinant proteins (r-proteins) are becoming increasingly popular both on the biotechnology market and in the pharmaceutical industry. An r-protein may be produced effectively through the transient transfection method, used also in this thesis. Cell culture 293HEK EBNA 1 was temporarily genetically modified (i.e. transiently transfected) by the gene of interest (AIM) using polyethyleneimine (PEI) as a transfection agent in two different transfection densities (i.e. “current” density and “test” density). The current transfection density was 20x106 cells/ml and the higher test density was 30x106 cells/ml. The aim of this Bachelor’s thesis was to determine whether the higher test transfection density of cells in transient transfection (as compared to the lower commonly used “current” transfection density) leads to higher yields of r-protein. A gene for the AIM protein (apoptotic inhibitor secreted by tissue macrophages) was temporarily inserted in cell culture 293 HEK EBNA. The successfully transfected cell cultures were purified on the Ni-NTA matrix and the amount of the r-protein obtained was quantified. It was ascertained that the r-AIM protein was always found in higher concentrations in the suspensions of the current transfection density of 20x106 cells/ml. Partial results showed that cultivation of cell culture 293HEK EBNA 1 in rectangular vessels leads to a higher cell density and viability in the course of the r-protein production as compared to the cultivation of the production culture in tubes.
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Preparation of recombinant inhibitor of serine proteases from the tick \kur{Ixodes ricinus}
VLNOVÁ, Ivana
Tick serine protease inhibitors could be important anti-tick vaccines targets because of their properties and functions. The aim of this work was to prepare recombinant inhibitor of serine proteases from the tick Ixodes ricinus in baculovirus expression system. Two tick saliva proteins of the serpine superfamily were selected for this purpose and transformed into plasmids. One recombinant protein was expressed in baculovirus expression system, purified and its biochemical analyses were done.
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Cloning and expression of a portion of \kur{Bombyx Mori Ser/2} gene
KONÍKOVÁ, Tereza
A 897 bp section of Bombyx mori Ser-2 gene was amplified, cloned into a bacterial expression vector, and used to prepare a recombinant sericin-like protein. The protein is expected to contain domain supporting growth of mammalian cells. It will be used in assays verifying this assumption; if confirmed, recombinant protein will be considered for preparations of scaffold guiding tissue reconstruction.
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Expression of osmotin, an antifungal protein from Nicotiana tabacum in Escherichia coli
Viktorová, J. ; Macková, M. ; Macek, Tomáš
Plants have evolved a huge variety of proteins involved in the defense against pathogens and adaptation to stressful environments. Plant proteins whose expression is strongly induced in response to infection by pathogens belong to the group of pathogenesis-related (PR) proteins. The family of PR-5 proteins constitutes a group of cysteine-rich proteins including thaumatin, zeamatin and also osmotin. Osmotin is a cationic protein of 205 residues and molecular weight of 24 kDa. It was discovered and characterized in cells of Nicotiana tabacum var. Wisconsin 38. The plasmid harbouring cDNA of osmotin from Nicotiana tabacum was constructed for transformation of Escherichia coli. The osmotin gene was prepared in fusion with histidine tail to facilitate the isolation and purification from bacterial cells. Selection of transgenic colonies was based on antibiotic resistance. The hexahistidine-tagged osmotin was overexpressed in heterologous system by using pET expression vector and purified using immobilized metal affinity chromatography. The expression of osmotin was detected and antifungal activity was tested.
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Characterization of a defensin of the tick \kur{Dermacentor marginatus}
LEŠTINOVÁ, Kateřina
Antimicrobial peptides (AMPs), as a part of innate immune system of ticks and other living organisms, are able to eliminate pathogens. In ticks the most important group of AMPs is defensin family. In this work, defensin from the tick D. marginatus was studied. The defensin gene was isolated from D. marginatus fed females. Using RT-PCR the gene expression was detected in salivary glands and mitgut. Recombinant protein was expressed in the procaryotic expression system, purified and tested for its antimicrobial activity. Specific polyclonal rabbit antibodies (anti DR IgG) were prepared and tested for their specifity and sensitivity.
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