Národní úložiště šedé literatury Nalezeno 17 záznamů.  1 - 10další  přejít na záznam: Hledání trvalo 0.01 vteřin. 
Tail labelled oligonucleotide probes for the detection of DNA-protein interactions
Pivoňková, Hana ; Němcová, Kateřina ; Horáková Brázdilová, Petra ; Havran, Luděk ; Macíčková-Cahová, Hana ; Hocek, Michal ; Fojta, Miroslav
DNA-protein interactions can be monitored via different ways. We introduce novel, fast and simple approaches in DNA-protein interaction detection based on electrochemical measurements of DNA alone (structure-sensitive DNA sensing), or DNA modified with osmium tetroxide bearing nitrogenous ligands, or measurements of redox-active moieties enzymatically attached to the end of a DNA substrate thus forming a labeled tail (by terminal transferase).
Redox labelling of nucleic acids for analyzing nucleotide sequences and monitoring DNA-protein interactions
Fojta, Miroslav ; Havran, Luděk ; Horáková Brázdilová, Petra ; Pivoňková, Hana ; Kostečka, Pavel ; Macíčková-Cahová, Hana ; Raindlová, Veronika ; Vrábel, Milan ; Hocek, Michal
Nucleobase labelling of DNA for electrochemical sensing was attained through chemical modification of thymine bases with osmium tetroxide in the presence of nitrogenous ligands, or via enzymatic incorporation of nucleotide conjugates with redox-active moieties using labelled deoxynucleoside triphosphates. DNA hybridization, primer extension and PCR techniques were used for sequence-specific DNA assays. Tail-labelled DNA substrates were applied to monitor DNA binding by tumour suppressor p53 protein.
Direct enzymatic synthesis of aldehyde-functionalized DNA and its conjugation with hydrazines and amines
Raindlová, Veronika ; Hocek, Michal
A new simple methodology for DNA conjugation or staining was developed. 2′-Deoxyribonucleoside triphosphates (dNTPs) bearing reactive aldehyde group were prepared by one-step Suzuki cross-coupling reaction of halogenated dNTPs with boronic acid. These modified dNTPs were enzymatically incorporated into DNA by primer extension (PEX) or amplified by polymerase chain reaction (PCR) using different DNA polymerases. The followup reaction between aldehyde-modified PCR products and hydrazine derivatives gave coloured DNA conjugated hydrazones. This methodology was also used for further conjugations of aldehyde-modified 2′-deoxyribonucleoside monophosphates (dNMPs) with amines by reductive amination.
Polymerase synthesis of modified DNA containing cytosine in major groove
Kielkowski, Pavel ; Hocek, Michal
(Cytosine-5-yl)ethynyl derivatives of pyrimidine and 7-deazaadenine 2-deoxyribonucleosides and nucleoside triphosphates (dNTPs) were prepared by aqueous Sonogashira coupling. All modified dNTPs were excellent substrates for DNA polymerases to give DNA bearing acetylene- linked cytosine(s) in the major groove.
Synthesis of nucleotides bearing oligopyridine ligands and their incorporation into DNA
Kalachová, Lubica ; Hocek, Michal
The synthesis of 7-deaza-dATPs and dCTPs bearing bipyridine or terpyridine ligands via acetylene tethers was accomplished through Pd-catalyzed cross-coupling reactions. Different DNA polymerases were used for their incorporation into DNA.
Modular synthesis of 5-substituted thiophene and furan C-nucleosides and their analogues
Bárta, Jan ; Hocek, Michal
A new modular and efficient methodology for the preparation of 5-substituted thiophen-2-yl and 5-substituted furan-2-yl C-nucleosides was developed. A Friedel–Crafts-type of C-glycosidation of 2-bromothiophene or 2-bromofuran with bis-toluoyl protected methyl- 2′-deoxyribofuranoside in presence of Lewis acid gave the desired bis-toluoyl protected 5-bromothiophne and 5-bromofuran C-nucleosides in good yields. They were used as key intermediates for Stille or Suzuki coupling whith (hetero)arylstannanes or boronic acids to afford a series of 5-(hetero)aryl thiophene and 5-(heteroaryl)furan C-nucleosides.
Synthesis of nucleosides and nucleoside triphosphates bearing anthraquinone substituents as redox probes and their enzymatic incorporation to DNA
Balintová, Jana ; Havran, Luděk ; Fojta, Miroslav ; Hocek, Michal
Modified 2′-deoxynucleosides and nucleoside triphosphates (dNTPs) bearing anthraquinone (AQ) via acetylene or propargylcarbamoyl linkers were prepared by single-step Sonogashira cross-coupling reactions halogenated nucleosides (7-iodo-7-deaza-2′-deoxyadenosine and 5-iodo-2′-deoxycytidine) or dNTPs with N-(2-propynyl)-anthraquinone carboxamide and 2-ethynylantraquinone. Polymerase incorporation of the AQ-labelled dNTPs into DNA has also been studied. Square-wave voltammetry of the AQ-labelled nucleosides and nucleotides showed one reversible peak at –0.5 V.
Synthesis of biaryl-substituted fluorescent nucleosides and nucleoside triphosphates and their incorporation to DNA
Riedl, Jan ; Hocek, Michal
A series of modified nucleosides bearing the fluorescent substituted biaryl labels attached to nucleobase was prepared and their luminescent properties were evaluated. The modified nucleosides show divers fluorescence from 400 to 560 nm when excited at 340 nm in water depending on structural and substitution pattern. The corresponding biaryl-substituted nucleoside triphosphates (dNTPs) were prepared analogously and used for polymerase incorporation to DNA. Applications in hybridization probes were studied.
Development of a general and modular approach to C-nucleosides
Kubelka, Tomáš ; Štefko, Martin ; Bárta, Jan ; Joubert, Nicolas ; Urban, Milan ; Chapuis, Hubert Jean ; Hocek, Michal
Highly efficient and modular approach was developed for the synthesis of various types of new (het)aryl C-nucleosides. This protocol consists of the synthesis of haloaryl-C-nucleoside intermediates, followed by a functional group transformation to introduce various substituents. Using this approach protected 2′-deoxy-C-nucleosides bearing halogenated benzene, pyridine, thiophene, furane and pyrimidine were prepared. These intermediates were then submitted to a wide range of palladium-catalyzed reactions. The same approach was also used for preparation of C-nucleosides bearing ribofuranose moiety. Functional ribofuranosides bearing diverse substituted pyridine and benzene nucleobases were prepared in this way.
Polymerase construction of base-modified DNA for chemical biology
Hocek, Michal ; Macíčková-Cahová, Hana ; Kielkowski, Pavel ; Raindlová, Veronika ; Kalachová, Lubica ; Riedl, Jan ; Balintová, Jana ; Ménová, Petra
An efficient two-step methodology for construction of base-modified DNA was developed based on aqueous-phase cross-coupling reactions of halogenated nucleoside triphosphates (dNTPs) followed by polymerase incorporation. A number of diverse chemical modifications have been successfully incorporated in this way for the use in chemical biology (modulation of cleavage by restriction enzymes, interactions with diverse DNA-binding proteins and bioconjugations).

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