21,135 research outputs found

    Spektroskopische Untersuchungen zur Bestimmung von RNA-Ligand-Wechselwirkungen und RNA-Dynamiken

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    This thesis describes the structural characterization of interactions between biological relevant ribonucleic acid biomacromolecules (RNAs) and selected ligands to optimize the methodologies for the design of pharmacological lead compounds. To achieve this aim, not only the structures of the RNA, the ligand and their complexes need to be known, but also information about the inherent dynamics, especially of the target RNA, are necessary. To determine the structure and dynamics of these molecules and their complexes, liquid state nuclear magnetic resonance spectroscopy (NMR) is a suitable and powerful method. The necessity for these investigations arises from the lack of knowledge in RNA-ligand interactions, e.g. for the development of new medicinal drugs targeting crucial RNA sequences. In the first chapters of this thesis (Chapters II to IV), an introduction into RNA research is given with a focus on RNA structural features (Chapter II), into the interacting molecules, the biology of the specific RNA targets and the further development of their ligands (Chapter III) and into the NMR theory and methodologies used within this thesis (Chapter IV). Chapter II begins with a description of RNA characteristics and functions, placing the focus on the increasing attention that these biomacromolecules have attracted in recent years due to their diverse biological functionalities. This is followed by a detailed description of general structural features of RNA molecules. The biological functions of the RNAs investigated in this thesis (Human immunodeficiency virus PSI- and TAR-RNA and Coxsackievirus B3 Stemloop D in the 5’-cloverleaf element), together with their known structural characteristics are introduced in Chapter III. Furthermore, a description of the investigated ligands is given, focusing on the methods how their affinity and specificity were determined. The introduction is completed in Chapter IV, where the relevant NMR theory and methodologies are explained. First, kinetics and thermodynamics of ligand binding are summarized from an NMR point of view. Subsequently, a detailed description of the resonance assignment procedures for RNAs and peptidic ligands is given. This procedure mainly concentrates on the assignment of the proton resonances, which are essential for the later structure calculation from NMR restraints. The procedure for NMR structure calculation of RNA and its complexes follows with a short introduction into the programs ARIA and HADDOCK. The final part of this chapter explains the relaxation theory and the methodology to extract dynamic information from autocorrelated relaxation rates via the model-free formalism. In the Chapters V to VII of this thesis, the original publications are included and grouped into three topics. Chapter V comprehends the publications on the investigations of HIV PSI-RNA and its hexapeptidic ligand. These three publications[1-3] focus on the characterization of the ligand and its binding properties, its structure and the optimization of its composition aiming to improve its usage for further spectroscopic investigations.Die vorliegende Doktorarbeit behandelt die strukturelle Aufklärung von Wechselwirkungen zwischen biologisch relevanten Ribonukleinsäuren (RNA) und ausgewählten Liganden, sowie die Bestimmung der inhärenten Dynamik der RNA, um zur Methodenentwicklung für den Entwurf neuer Pharmaka beizutragen. Zur Bestimmung sowohl der Strukturen, als auch der Dynamiken stellt die Flüssig-Kernspinresonanz-Spektroskopie (NMR) eine ideale biophysikalische Methode dar. Die ersten Hälfte dieser Doktorarbeit gibt zum einen eine Einleitung in die RNA-Forschung mit besonderem Fokus auf den allgemeinen strukturellen und dynamischen Eigenschaften von Ribonukleinsäuren, stellt zweitens die ausgewählten RNA-Zielstrukturen und deren mit verschiedenen Methoden bestimmten Liganden vor, und erklärt drittens die zugrundeliegende NMR-Theorie und die verwendeten Methoden zur Untersuchung der Bindungs¬charakteristika, zur Strukturbestimmung der RNA und der Liganden und zur Ableitung dynamischer Parameter aus experimentellen Daten. Die zweite Hälfte dieser Arbeit ist der kumulative Teil und enthält die Originalpublikationen, die in drei Themenbereiche eingeteilt sind. Zuerst sind die drei Publikationen gruppiert, in denen die Bestimmung und Charakterisierung peptidischer Liganden der HIV Psi-RNA und deren Wechselwirkungen miteinander behandelt werden. Durch einen Phage-Display Assay wurde zunächst eine Konsensus¬sequenz eines peptidischen Liganden identifiziert (HWWPWW). Zur Verbesserung der Bindungseigenschaften wurde das Hexapeptid mittels einer Sequenzvariierung auf einer Membranoberfläche (SPOT-Assay) weiter optimiert (HKWPWW). Die weiteren strukturellen Untersuchungen der RNA-Ligand-Wechselwirkungen wurden per Fluoreszenz- und NMR-Spektroskopie durchgeführt, wobei die NMR-Spektroskopie aufzeigen konnte, dass das Peptid HKWPWW in zwei Konformationen der zentralen Prolinpeptidbindung zu beinahe gleichen Anteilen vorliegt. Die nächsten zwei Publikationen beschreiben die Ligandselektion gegen die Zielstruktur HIV TAR und die Strukturaufklärung des Komplexes mittels NMR-Spektroskopie. Als Liganden wurden Tripeptide synthetisiert, in denen zwei Arginine eine synthetische Aminosäure mit aromatischen oder hetero¬aromatischen Gruppierungen in ihrer Seitenkette flankieren. Mittels Fluoreszenz-Resonanz¬energietransfersichtung (FRET-Assay) wurde eine Vorauswahl der Liganden vorgenommen und die Interaktionen der ausgewählten Liganden mit der RNA per NMR-Spektroskopie konkretisiert. Eine intensive strukturelle Untersuchung des Liganden mit einer Pyrimidinylgruppe in der Seitenkette der zentralen Aminosäure in Komplex mit der TAR RNA ergab eine 2:1 Bindungsstöchiometrie des Liganden. Die erste stärkere Bindungsstelle im Bulge der RNA war bereits weitgehend bekannt als Ziel von Arginin-tragenden Liganden. Die strukturellen Untersuchungen konnten jedoch auch die zweite Bindungsstelle des Tripeptids unterhalb des Bulges lokalisieren. Zuletzt sind die zwei Publikationen zur Untersuchung der RNA-Dynamik zusammengefasst. Aus autokorrelierten Relaxationsraten der Kerne C1’ und C8 (für Purine) bzw. C6 (für Pyrimidine) in Nukleotiden der RNA Tetraloopsequenzen UUCG und CACG wurden mittels des Model-Free Formalismus Parameter abgeleitet, die über Dynamiken auf der Zeitskala von Pico- bis Nanosekunden der C-H Vektoren berichten. Die Verwendung optimierter und neuer Werte der C-H Bindungslänge und der Anisotropie der 13C-chemischen Verschiebung (13C-CSA) ermöglichte eine genauere Ableitung der inhärenten Dynamiken dieser RNA Moleküle. Diese Informationen konnten in die strukturellen Untersuchungen der glykosidischen Bindung durch kreuzkorrelierte Relaxationsraten eingebaut werden. Des Weiteren konnten die dynamischen Parameter bei verschiedenen Temperaturen mit Parametern abgeglichen werden, die aus Molekular-Dynamischen (MD) Trajektorien abgeleitet wurden. Dies ermöglichte die Visualisierung der internen Bewegungen zweier strukturell ähnlicher Tetraloops aus der YNMG-Familie, die sich aber in ihrer Stabilität unterscheiden. Bei Temperaturen nahe dem Schmelzpunkt des weniger stabilen CACG-Tetraloops offenbarten sich die Änderungen in der Dynamik, die zum Aufschmelzen des Loops führen

    Jan Kapr's contribution to contemporary music : an essay about a composer and teacher

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    This creative project is a treatise on a leading personality of Czechoslovakian musical life, the composer, Jan Kapr. The author discusses the following:1. The complicated development of Kapr's career and work, 2. Kapr's method of organization of musical material in a composition, as described in his book Constants,3. His former and current style which is demonstrated in two of his compositions, Concert Variations, for flute and string orchestra and Testimonies for four solo instruments,4. Two of his recent works, Exercises for Gydli and the Symphony No. 7, Country of Childhood.Thesis (M.A.

    Going Beyond Counting First Authors in Author Co-citation Analysis

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    The present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed

    ELEVEN FACES OF JAN GOGOL, JR.

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    Author Jan Rendl in his thesis attempts to look at the world of ideas and educator Jan Gogola ml. through the eleven chapters in which each chapter somehow characterizes itself by Jan Gogola ml. and each of them somehow determines its creative ideas of it through the metaphor of a football match when Jan Gogola, with its characters, movies himself a teammate, as well as defensively. It gives goals with their situations as well as occasionally digging his opponents ankles. Jan Gogola ml. thus embodies one stage of the Department of Documentary Film at FAMU, which often stands at the intersection between teaching activities and Karel Vachek among students who applied by them during their seminars psychological methods that work must be peculiarly associated with the author of the film

    Dr. Jan French – Faculty Author Interview

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    Dr. Jan French, Assistant Professor of Anthropology, discusses her new book, Legalizing Identities: Becoming Black or Indian in Brazil’s Northeast, which shows how law can successfully serve as the impetus for the transformation of cultural practices and collective identity

    Jan Bernátek - organ works

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    This graduation thesis provides a more detailed view on compositoins of Jan Bernátek.The aim is to present this less well-known temporary czech author,who makes use of the organ in the majority of his work

    The Theological Work of Jan Valerián Jirsík

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    Anglická anotace The theological work of Jan Valerian Jirsík Jan Hamberger This thesis deals with the theological work of the Czech 19th century author Jan Valerián Jirsík (1798-1883). Its first part consists of an introduction into the Czech historical context of the 19th century and the life of the author. Its second part presents a survey of the literary-theological work of Jirsík in three life phases: the first phase is demarked by his activity as chaplain and vicar, the second phase by his editorial activity for Casopis pro katolické duchovenstvo (trans. Magazine for catholic clergy) and the last phase by his pontifical years in the diocese of Southern Bohemia. His literary work is divided by theme into various periods, shortly described and characterized. The last and major section of this thesis deals with the most comprehensive and renown work of Jan Valerián Jirsík - Populární dogmatika (trans. Popular doctrine). This pivotal work of theologian Jirsík is discussed at large and analyzed by tractate, both apologetic and dogmatic. The conclusion expresses the prevailing character of the entire work of Jirsík and its significance. Key words: Theology Apologetic theology Dogmatic theology Theological literature Catholic Churc

    Actor Profile of Jan Vondracek

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    Divided into seven chapters, the work treats seven roles of the Czech actor Jan Vondracek (born in 1966) in Divadlo v Dlouhe Theatre from 1997-2008. The author starts from the analysis of Vondracek's performances and describes the specifics of his showmanship and generalizes the personality traits of his characters. She also ponders the meaning of Czech dramatic art based on typical characters in the context of contemporary Czech theatre

    The picture of Jan Palach in czech culture

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    This thesis deals with cultural image of Jan Palach. It focuses especially on symbols and myths contributing to construction of this image. The main emphasis is given on the concept of sacrifice - the study analyzes comparisons of Jan Palach to archetypes of Jesus Christ and young martyrs. In the second part author analyzes national dimension of Palach's cultural image. She deals with comparison of Palach to Jan Hus and analyzes Palach's funeral as a part of tradition of Czech public funerals - quiet national demonstrations. The methodology of the study is discourse analysis, which is applied not only on texts (fiction and nonfiction), but also on photographic and film footage

    Jan Maruna - the author of my region

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    Na začátku práce jsem autora blíže představila a následně analyzovala jeho tři romány: Ambra a moře v nás, Hrobník od Svatého Bartoloměje, Vlak do nebe. Při rozboru textů jsem se zaměřila na téma, prostředí a čas, charakteristiku postav, kompozici, jazyk a jeho prostředky. Práce je rozdělena do čtyř hlavních kapitol: Portrét Jana Maruny, Vybrané romány, Analýza struktury vybraných děl a Ostatní prozaická díla v kontextu Jana Maruny.Katedra českého jazyka a literaturyObhájenoAt the beginning of the thesis I introduced the author in more detail and subsequently analysed his three novels: Ambra a moře v nás, Hrobník od Svatého Bartoloměje, Vlak do nebe. When I was examining the texts I was focused on the topic, setting and time, characteristic of characters, composition, language and its devices. The Bachelor thesis is divided into 4 main chapters: Portrait of Jan Maruna, Chosen novels, Analysis of structure of chosen works and Other prosaic works in context of Jan Maruna
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