|
|
Antioxidant and antiinflammatory effects of bilirubin.
Valášková, Petra ; Muchová, Lucie (advisor) ; Martínková, Markéta (referee) ; Dvořák, Karel (referee)
For a long time, bilirubin (BR) has been considered a waste molecule with potential toxic effects especially on the central nervous system. Later, it was found that BR exhibited cytoprotective effects and mildly elevated BR levels showed antioxidant, anti-inflammatory and immunomodulatory properties, however, exact mechanisms of the anti-inflammatory actions of BR have not been fully understood yet. The main aim of this study was to assess the protective effects of BR using experimental in vivo and in vitro models in relation to inflammation and oxidative stress. Partial goal was to establish validated analytical method for determination of BR and lumirubin. Gunn and heterozygous rats were treated with lipopolysaccharide (LPS, 6 mg/kg, IP) or vehicle (saline). After 12 hours, blood and organs were collected for analyses of inflammatory and hepatic injury markers. Primary rat hepatocytes were treated with BR and TNF-α, HepG2 and SH-SY5Y cell lines were treated with BR and chenodeoxycholic acid. LPS-treated Gunn rats had a significantly decreased inflammatory response and hepatic injury compared to LPS- treated normobilirubinemic controls. We found different profile of leukocytes subsets and decreased systemic mRNA expressions and concentrations of IL-6, TNF-α, IL-1β and IL-10 in Gunn rats. Hepatic mRNA...
|
|
| |
|
|
Study of mechanism of signal transduction in case of two model heme-containing sensor proteins
Mihalčin, Peter ; Martínková, Markéta (advisor) ; Kavan, Daniel (referee)
Heme-based gas sensing proteins belong to a group of proteins that are present in signalling pathways of bacteria. A precise regulation of physiological functions, such as intercellular communication or biofilm production, is essential for the survival of these bacteria and their adaptation to the changing surrounding conditions. Heme-based gas sensors are able to detect the concentration of gas molecules in the local environment via their sensory domain (which contains a heme molecule as the intrinsic detection site) and transmit the signal to the functional domain helping to regulate the adaptation of many processes. These, often pathogenic, processes contribute to extended resistance of bacteria against antibiotics. Heme-based sensors are thus potentially a new therapeutic object of interest in antimicrobial treatment. In order to provide this type of treatment, it is crucial to understand the exact mechanism of intramolecular signal transduction facilitated by heme-based sensors. One of the approaches to unravel these mechanisms is further study of model sensory proteins. This thesis focuses on the analysis of a signal transduction performed by two model globin-coupled heme-based oxygen sensors.
|
|
|
Comparison of apo- and holoforms of the transcription factor "Bach1"
Vávra, Jakub ; Martínková, Markéta (advisor) ; Brynychová, Veronika (referee)
Hemoproteins represent very important components of many living organisms. Participation in the processes of oxygen transport and storage, electron transport or enzymatic catalysis of reactions involving oxygen or hydrogen peroxide are commonly known functions of hemoproteins. Recently, there has been discovered a new group of hemoproteins. The main feature of this new group of proteins is their ability to detect changes in heme concentration (heme-responsive proteins) or changes in diatomic gas concentration (gas-responsive heme-containing sensor proteins) in their vicinity. Detection of these concentration changes generates signals that induce structural changes of the respective sensor proteins. Finally, the structural changes of the respective sensor proteins affect their functions or activities. The subject of this diploma thesis is the preparation and characterization of the eukaryotic heme sensor Bach1. We especially focused on the ability of Bach1 to bind heme molecules and on the comparison of various Bach1 properties in its apoform and holoform. Determination of the exact amount of heme molecules that specifically interact with heme sensor Bach1 represents very important part of this thesis. We also studied the effect of different redox states of heme iron and the presence of interaction...
|
|
|
Study of regulation and function of DNA repair enzymes UBE2T and FANCL
Hušková, Andrea ; Šilhán, Jan (advisor) ; Martínková, Markéta (referee)
Due to the action of endogenous and exogenous agents, DNA is subject up to 70,000 lesions per day, thus the existence of repair mechanisms and enzymes is more than necessary. We know basic mechanisms of several specific DNA repair pathways, of which the Fanconi anaemia (FA) repair pathway is one of the least explored. FA is a rare, autosomal recessive disorder characterized by early onset bone marrow failure, developmental defects, genomic instability and predisposition to acute myeloid leukaemia and solid tumours. The primary diagnosis of FA is a hypersensitivity to cross-linking agents of DNA due to inactivation of one of the 21 genes from the FA repair pathway, the so-called FANC genes (FA complementation group). The molecular defect in FA is an impaired repair of DNA interstrand cross-links (ICLs). The ICLs are cytotoxic lesions that inhibit the process of DNA replication and transcription. A crucial step in the FA pathway that initiates ICL repair is a monoubiquitination of FANCD2. FANCD2 monoubiquitination is a base for the recruitment of additional proteins that coordinate DNA repair. Ubiquitin is recruited via activating enzyme E1 (UBA1), ubiquitin-conjugating enzyme E2T (UBE2T) and transferred onto FANCD2 by multisubunit E3 ligase (FA core complex). There are up to 11 different proteins...
|
|
|
Characterization of selected properties of model heme-containing sensor proteins
Fojtík, Lukáš ; Martínková, Markéta (advisor) ; Svášková, Dagmar (referee)
Heme sensor proteins are the fourth group of hemoproteins. In this group of hemoproteins heme plays an important role in signalization. Dissociation and/or association of heme detecting proteins serves as an important physiological function in regulation of enzyme activity or gene expression. In this bachelor thesis all the actual knowledge about selected forms of eukaryotic heme sensor proteins previously published in scientific articles are summarized. The experimental part of this bachelor thesis is focused on preparation of recombinant protein heme regulated inhibitor (HRI) and its substrate eukaryotic translation initiation factor 2 alpha (eIF2α). Firstly the preparation of the plasmids with genes HRI and eIF2α was conducted. In the next step these proteins were prepared in prokaryotic system formed by E. coli BL-21(DE3). The final sample of HRI (7,7 μM in total volume 400 µl and 60 % of homogenity) and the final sample of eIF2α (51,3 μM in total volume 400 µl and 80 % of homogenity) were obtained by the purification process. The study of thermal stability of these samples provided important informations on appropiate storage and manipulation with them in further experiments. Key words: heme-base sensors, heme, kinase, tranduction of signal, isolation of plasmids, prokaryotic expresion,...
|
|
|
Enzyme activity analysis of function domains belonging to model heme-containing sensor proteins
Prošková, Veronika ; Martínková, Markéta (advisor) ; Macek, Tomáš (referee) ; Vítek, Libor (referee)
EN This Ph.D. thesis focuses on the heme containing gas sensor proteins. These proteins are predominantly present in bacteria, in which play an important role in processes like, sporulation, antibiotic resistance and so on. Heme containing sensor proteins composed of two domains. First one is a globin domain, which contains the heme molecule. Interaction of heme with gas molecule acts as a signal for the activation/inactivation of the second functional domain. Part of this thesis is formed by a review, which summarized the current knowledge about heme containing sensor proteins. In the next part of this thesis we focused on three representatives from the group of oxygen sensor proteins - histidine kinase AfGcHK, diguanylate cyclase YddV and phosphodiesterase EcDOS. The main aim of this thesis was to solve the mechanism of interdomain/intraprotein signal transduction in two oxygen sensor proteins with globin fold of their sensor domain (AfGcHK, YddV). For this purpose, we used the kinetic analysis of their functional domain activity and the methods of structural biology. We also studied the mechanism of interprotein signal transduction in AfGcHK and its cognate partner RR protein. It was also tested, how the presence of sodium disulfide affects the functional properties of oxygen sensor proteins...
|
|
| |
|
|
Examples of good practice in teaching English grammar through the inductive metod
MARTÍNKOVÁ, Markéta
The master thesis describes in its introduction the deductive and inductive approach to teaching English grammar, compares them, and also lists the pros and cons of each approach. The main content of the theoretical part is the presentation of key concepts and principles of inductive teaching of English grammar. The practical part converts theoretical knowledge to real grammar teaching. Pupils learned how to express past events within four lessons. These sample lessons are examples of good practice of teaching grammar inductively. The reflection of these lessons is provided at the end of this part.
|
|
| |
guest ::
RSS feed.