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Natural and Synthetic Components of Nucleic Acids as Reactive Sites for DNA Modification by Osmium Tetroxide Complexes
Havran, Luděk ; Špaček, Jan ; Rozkosna, Jana ; Fojta, Miroslav
Natural DNA electroactivity find wide use in electrochemical analysis of its interactions and damage. For some applications is useful applied redox active tag to improve specificity of the analysis. One from utilized labels in this field are complexes of osmium tetroxide with nitrogen ligands (Os, L), which produce with DNA electroactive covalent adducts. Prime reaction site for Os, L is C=C double bond in pyrimidine nucleobases. If is 2,2'-bipyridine used as ligand, reaction is specific for single strand DNA. In this contribution will be presented results of electrochemical analysis of Os, bipy adducts with different ODN containing chemically modified purine bases.
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Electrochemical Reduction and Oxidation of Nucleic Acids Bases and their Analogues: a Brief Overview
Fojta, Miroslav ; Špaček, Jan ; Dudová, Zdenka ; Pivoňková, Hana ; Daňhel, Aleš ; Fojt, Lukáš ; Havran, Luděk
Nucleic acids are known as electroactive biomacromolecules containing electrochemically reducible or oxidizable constituents. Nucleobases cytosine, 5-methylcytosine, adenine and guanine can be reduced in aqueous media on mercury or silver amalgam electrodes. Oxidation of all natural nucleic acids bases (in addition to the above mentioned ones, also uracil and thymine) was demonstrated using various types of carbon electrodes. Some of synthetic nucleobases or nucleotide analogues (e g., 7-deazapurines, cytidine analogues used as epigenetic modulators, etc.) exhibit specific electrochemical properties that differ from those of the parent bases and can be utilized to determine the given substance in the presence of natural nucleic acids or their components.
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Synthetic Biology Introduces New Base Pairs to Analyze
Špaček, Jan
An unnatural base pair is composed of two nucleobase analogues which specifically Pair only with each other similarly as natural DNA pairs do. Goal of the search for new base pair is expansion of genetic alphabet with new codons containing unnatural bases. Expanded genetic alphabet am, other things allows simultaneous site specific incorporation of non-standard amino acids into proteins Recently unnatural bases forming pairs vie hydrophobic interactions, which can be replicated by prokaryotic cells with efficiency and mutation rate similar to natural base pairs, have been shown. Synthetic biology provides new opportunities for application of electrochemical analysis.
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Analysis of Denatured PCR Products Modified with 7-deazapurine Bases at Hanging Mercury Drop Electrode
Dudová, Zdenka ; Špaček, Jan ; Havran, Luděk ; Pivoňková, Hana ; Fojta, Miroslav
7-deazapunines are synthetic analogues of natural purine nucleobases which can pair with pyrimidines, retaining pairing complementarity of their parent purines. There is replaced N7 atom by CH group in 7-deazapurines so that DNA modified with them don't participate in Hoogsteen basepairing and don't form alternative structures. Here is a study of 7-deazapurines incorpotated into DNA measured at HMDE by CV and ACV. While 7-deazaadenine was reduced at the HMDE, giving rise to a similar irreversible cathodic peak as the natural adenine, 7-deazaguanine didn't yield any peak analogous to the peak G due to Guanine, in Agreement with a loss of corresponding redox in 7-deazaguanine.
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Novel Reactive Groups for Modification DNA by Oxoosmium Complexes
Havran, Luděk ; Vidláková, Pavlína ; Špaček, Jan ; Hermanová, Monika ; Fojta, Miroslav
DNA is naturally electroactive moleclue producing several intrinsie voltammetric signals. Some of them found appliction in electrochemical analysis of DNA interactions and damage. In particular types of applictaions is a suitable use DNA labelling by redox active tags to increase selectivity and sensitivity of analysis.One type of long-term used tags are complexes of osmium tetroxide with nittrogen ligunds (Os,L). These complexes preferentially react with pyrimidines in single stand DNA producing electractive adducts. primary reaction site for Os,L is C-C double bond in pyrimidine nucleobases. In this contribution will be presented results acquired with DNA containing chemically modified nuclebase.
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Electrochemical Study of Osmium Tetroxide Comptests Reactivity to DNA Bearing Butylacrylate
Havran, Luděk ; Havranová-Vidláková, Pavlína ; Špaček, Jan ; Vítová, Lada ; Hermanová, Monika ; Fojta, Miroslav
Coniplexes of osmium tetroside with nitrogen ligands (Os,L e.g.. with 2,2'-bipyridine (bpy) find application in redox labelling of DNA.. probing of DNA structure, and in studies of DNA interaction with other molecules Os,L preferentially react with pyrimidines in single strand DNA producing electroactive adducts Primary reaction site for Os,L is C=C double bond in pyrimidine nucleobases. In this contribution we introduce a new two-step technique of DNA modification with Os,bpy, consisting in enzymatic construdion or DNA beating butyl acrylate (BA) moieties attached to uracil or T-deaza adenine, followed by chemical modification of a reactive C=C double bond in BA residue.
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Safety inspections in region Vysocina
Špaček, Jan ; Radimský, Michal (referee) ; Matuszková, Radka (advisor)
This thesis presents a safety inspection in selected places in the Vysocina region of the Czech Republic. Six intersections in rural and municipal areas, plus three rural road sections were selected for the inspection and an accident rate analysis. The places selected were compared in terms of the accident rate and one case of each group was then selected for a detailed safety inspection encompassing visual inspection and identification of possible hazards. By eliminating such safety hazards, it is possible to ensure a traffic fluency and to preclude traffic accidents or at least minimize the harm caused by it.
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Bass string instruments used in church and folk music in Prague and central Bohemia
Špaček, Jan ; ŽALUD, Radomír (advisor) ; HUDEC, Jiří (referee)
This thesis is aiming to summarize and compare instruments used in church and folk music in Prague and central Bohemia. At first it names various types
of instruments and describes their characteristics. Then pick few makers
who influenced development and expansion of double bass in the land, and following
with pick of particular instruments and their description.
Last part of this thesis speaks of Ondrej Hornik and his collection, which
is valuable source of information and tangible documentation of musical development in Czechia.
Included is an insert located at the end of this work.
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