Národní úložiště šedé literatury Nalezeno 52 záznamů.  předchozí11 - 20dalšíkonec  přejít na záznam: Hledání trvalo 0.01 vteřin. 
Strukturní flexibilita regulačního segmentu DNA
Řezáčová, Barbora ; Štěpánek, Josef (vedoucí práce) ; Rosenberg, Ivan (oponent)
Transcription of the genetic code is controlled by numerous proteins. Some of them, so-called transcription factors, bind to certain DNA regions possessing anomalous properties due to their specific and highly conservative base sequence. One of these DNA segments is SRE (Serum Response Element). The diploma work is linked to results of the previous study indicating that the structural flexibility of this segment, related to the CArG box sequence, plays a key role in its physiological activity. Our work is devoted to study of this DNA segment and its model sequential variants. The approach of accurate measurements of temperature dependent UV absorption spectra and their consecutive analysis by means of factor analysis techniques and difference spectra construction, the main part of which was also developed within the framework of this work, was employed. The results indicate that separate chains of SRE with various length form surprisingly stable hairpins, which in some cases prevail even in mixtures of both chains of the SRE segment over duplexes. By using a fitting to thermodynamic equilibrium equations, thermodynamic characteristics of temperature induced association and dissociation transitions of complexes, both intermolecular (duplexes) and intramolecular (hairpins), were obtained.
Synthesis of Prolinol-Based Phosphonate Nucleotide Analogues
Vaněk, Václav ; Rosenberg, Ivan (vedoucí práce) ; Černý, Miloslav (oponent) ; Moravcová, Jitka (oponent) ; Pour, Milan (oponent)
4.Závěr Byly pfipraveny dvě řady 3'-nukleotidových analog nového typu (9a-e a l0a.e), cr-I-- a p- -L-prolinolové nukleosid.N-methylťosfonové kyseliny, které jsou zajimavé především ztrátou jednoznačně definované konfigurace v 3'.poloze prolinolového kruhu v důs|edku přítomnosti dusíkového atomu' Výnamné konformačni rczdi|y mezi cr-r-. a p.t..prolinolov1/mi nukleotidy zjištěnéNMR studií naznaěuji určitou podobnost s pfirozenými 5'.o-nukleotidy. obdobné konformačni rozdíly v o-řadě prolinolových nukleotidů přibliŽují tato analoga přirozen1im 3'- a 5'-o.nukleotidům ještě výrazněji. Dále by,|y syntetizovány čtyři diastereomemí syntony 5-8 z komerčně dostupného trans-4- .hydroxy-l--prolinu, které jsou výchozimi látkami pro přípravu uce]ené sérieprolinolových nukleotidových analog s ct-L-, B-L-, cr-o- a p-o. konfiguraci' Ve snaze omezit konformačníflexibilitu N-fosťonomethylovéhouskupení bylo několik připravených pyrrolidinových derivátů podrobeno N.oxidaci a N-methylaci. které vedly ke vzniku N-oxidů a kvarterních amoniových solí. Příprava příslušných voJných fosfonových kyselin však byla neúspěšná, pravděpodobně následkem jejich rychJého rozkIadu. Acylace dusíkového atomu pynolidinového kruhu deriváty acylfosfonových kyselin vedla ke vzniku nových N-fosfonoformy|ových, N.fosfonoacetylových a...
Bi-substrate inhobitors of human pyrimidine 5’-nucleosidases
Šimák, Ondřej ; Pachl, Petr ; Jandušík, T. ; Brynda, Jiří ; Buděšínský, Miloš ; Rosenberg, Ivan
The work is aimed at the synthesis of bi-substrate inhibitors of 5’-nucleosidases. The pyrimidine nucleobase of lead compound was derivatized in the 5-position with various phosphonic acids differing in conformational flexibility and in the length of alkyl side chain carrying phosphonate group. The phosphonic acid with optimal linker can reach the phosphate binding side and make strong interaction with the enzyme. Inhibition activity of such inhibitors and crystal structure of inhibitor-enzyme complex will be presented.
Novel conformationally locked nucleosides and nucleotides based on bicyclo[3.2.1]octane scaffold as a pseudosugar moiety
Šála, Michal ; Dejmek, Milan ; Procházková, Eliška ; Hřebabecký, Hubert ; Rybáček, Jiří ; Dračínský, Martin ; Novák, Pavel ; Rosenbergová, Šárka ; Fukal, J. ; Sychrovský, Vladimír ; Rosenberg, Ivan ; Nencka, Radim
A route to a series of novel carbocyclic nucleosides locked in North conformation with bicyclo[3.2.1]octane scaffold was developed. Prepared nucleosides served as a starting material for the synthesis of modified oligomers [d(GCATATCAC), r(GCAUAUCAC), and A9]. Biological effects of the prepared nucleosides as well as the hybridization properties of the appropriate duplexes were evaluated.
Activation of human RNase L by 5’-C-phosphonate-modified oligoadenylates
Petrová, Magdalena ; Buděšínský, Miloš ; Zborníková, Eva ; Panova, Natalya ; Novák, Pavel ; Rosenberg, Ivan
Adeno’sine 5’-(S)-C-phosphonate (pCOHX) was prepared as monomer suitable for oligonucleotide synthesis. Modified tetramers pCOHXAAA and pCOHXAApCOHX were assembled on solid phase and evaluated for their ability to activate human RNase L.
Phosphanucleosides containing 1-hydroxymethylphospholane 1-oxide ring
Páv, Ondřej ; Zborníková, Eva ; Buděšínský, Miloš ; Rosenberg, Ivan
Novel phosphanucleosides containing 1-hydroxymethylphospholane 1-oxide ring were synthesized as compounds with potential biological activity. A ring-closing metathesis was employed to prepare a phospholene precursor, which was then converted into either 4-azido-3-hydroxy-1-hydroxymethylphospholane 1-oxide or 3-azido-1- hydroxymethylphospholane 1-oxide derivatives. Subsequently, nucleobase was introduced using a nucleobase construction. The biological activity of prepared compounds was evaluated.
Sulfur-containing phosphonate monomers for oligonucleotide synthesis
Kostov, Ondřej ; Zborníková, Eva ; Buděšínský, Miloš ; Novák, Pavel ; Rosenberg, Ivan
A series of novel compounds, protected S-MOP nucleoside-5’-O-methylphosphonothioates, was prepared as monomers for solid phase synthesis of phosphonothioate oligonucleotides. In addition we have examined the synthetic potential of nucleoside-5’-O-methyl-(H)-phosphinates for phosphonate oligonucleotide assembly.
Oligonucleotides modified with acyclic nucleoside phosphonate (HPEP) units
Kaiser, Martin Maxmilian ; Novák, Pavel ; Rosenbergová, Šárka ; Poštová Slavětínská, Lenka ; Rosenberg, Ivan ; Janeba, Zlatko
Two acyclic nucleoside phosphonates bearing 9-[3-hydroxy-2-(phosphonoethoxy)propyl] (HPEP) moiety and either adenine and thymine as nucleobase were synthetically converted into a suitable building blocks for the subsequent automated solid phase synthesis of modified oligonucleotides. Phosphoramidite chemistry was used for the synthesis of a series of complementary nonamers where the modified acyclic monomers were incorporated using the phosphotriester method. Determination of thermal characteristics of the complexes of the modified nonamers with the complementary strands revealed a destabilizing effect of the introduced acyclic modifications.

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