Sökning: "DNA and RNA conformation"
Visar resultat 1 - 5 av 22 avhandlingar innehållade orden DNA and RNA conformation.
1. Nucleic Acids as Drug Targets -Interactions of Platinum Complexes, Polyamines, and siRNA with DNA and RNA Models
Sammanfattning : Drugs targeting nucleic acids were studied in DNA and RNA model systems. The effects were investigated with respect to structural and thermodynamic influence, kinetics, and biological function. The drugs employed in this thesis were anticancer active platinum(II) complexes, polyamine derivatives, and siRNA. LÄS MER
2. Conformationally Constrained Nucleosides, Nucleotides and Oligonucleotides : Design, Synthesis and Properties
Sammanfattning : This thesis is based on six original research publications describing synthesis, structure and physicochemical and biochemical analysis of chemically modified oligonucleotides (ONs) in terms of their potential diagnostic and therapeutic applications. Synthesis of two types of bicyclic conformationally constrained nucleosides, North-East locked 1',2'-azetidine and North locked 2',4'-aza-ENA, is described. LÄS MER
3. Physicochemical and Structural Aspects of Nucleic Acids
Sammanfattning : This thesis consists of seven research publications concerning (i) pKa studies of nucleobases in model nucleotides to understand why RNA duplexes are more stable than DNA duplexes (Paper I), (ii) the role of Me(T)-π interactions in the relative stability of DNA-RNA heteroduplexes (Paper II), (iii) pKa measurements in nucleotides with different 2′-substituents (paper III), (iv) a conformation study of constrained sugars and a pKa study of 1-thyminyl to reveal effect of sugar constraints on the pKa of the nucleobase (paper IV), (v) NMR and MD studies of 1′, 2′-oxetane constrained thymidine incorporated Dickerson Drew dodecamer (paper V), (vi) the sequence dependent pKa perturbation of 9-guaninyl moeity in single stranded (ss) DNA and RNA (paper VI), (vii) the non identical chemical nature of internucleotidic phosphates in (ss) RNA using 31P NMR (paper VI), and an alkaline hydrolysis study of phosphodiesters in ssRNAs (paper VII). The architecture of DNA and RNA molecules is determined by (a) hydrogen bonding (b) base stacking (c) a variety of additional non-covalent interactions. LÄS MER
4. Redefining the essential molecular aspects that drive interactions between small molecules and G-quadruplex DNA
Sammanfattning : G-Quadruplex (G4) structures are secondary nucleic acid structures located in guanine-rich regions of DNA and RNA sequences, involved in gene regulation and cellular maintenance. Efforts to target G4s in a therapeutic setting are scarce, mainly due to vague details about the binding interactions between the ligands and the G4 structure combined with the lack of emphasis on drug-like properties early in the ligand development process. LÄS MER
5. Mechanisms for control of nucleoside triphosphate hydrolysis. Effects of DNA and RNA co-factors
Sammanfattning : In energetically unfavourable biological processes "protein machines" utilize chemical energy from the hydrolysis of high-energy phosphate bonds. Thus, the hydrolysis of a nucleoside triphosphate (NTP) to nucleoside diphosphate (NDP) with the release of free orthophosphate results in a liberation of energy. LÄS MER