Search for dissertations about: "DUPLEXES"

Showing result 1 - 5 of 26 swedish dissertations containing the word DUPLEXES.

  1. 1. Chemically Modified Oligonucleotides: Synthesis, Physicochemical and Biochemical Properties of their Duplexes with DNA and RNA

    Author : Pushpangadan Indira Pradeepkumar; Jyoti Chattopadhyaya; Jesper Wengel; Uppsala universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Bioorganic chemistry; Antisense oligonucleotides; Dipyridophenazine; Oxetane; RNase H; Gene down-regulation; DNase 1; Charge transport; Bioorganisk kemi; Bioorganic chemistry; Bioorganisk kemi;

    Abstract : This thesis is based on 9 papers dealing with the synthesis, physicochemical and biochemical properties of two types of chemically modified oligonucleotides which have the potential to down-regulate gene expression: (i) The first set is comprised of antisense oligonucleotides (AONs) conjugated with different chromophores of varying size, charge and π-electron density. Conjugation of the chromophores at the 3'- or 5'-end enhanced the target RNA binding affinity and RNase H recruitment capabilities compared to the native counterpart without changing the global helical conformation of their AON/RNA hybrid duplexes. READ MORE

  2. 2. Thermodynamics of Peptide Nucleic Acid Interactions with DNA

    Author : Tommi Ratilainen; Chalmers tekniska högskola; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; thermodynamics; enthalpy-entropy compensation; ionic strength; nucleic acids; fluorescence energy transfer; PNA; calorimetry; sequence-specific binding;

    Abstract : Peptide Nucleic Acid (PNA) is a DNA mimic with the natural nucleobases attached to a charge-neutral pseudopeptide backbone. It has remarkably strong and sequence-specific binding affinity to natural nucleic acids (DNA and RNA), mainly attributed to the lack of charge in the PNA backbone. READ MORE

  3. 3. Nucleic Acids as Drug Targets - Influence of Platinum Complexes on Duplex Stability and Binding Kinetics

    Author : Christopher Polonyi; Biokemi och Strukturbiologi; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Anticancer drugs; platinum complexes; cisplatin; oxaliplatin; nucleic acid; RNA; DNA; duplex melting; thermodynamic stability; kinetics; non-coding RNA; miRNA; siRNA; wobble base pair; loop; BRCA1; mimic; luciferase assay;

    Abstract : Gaining a detailed understanding of how human cells are affected by metal-based drugs is crucial, since these drugs have shown great potential in cancer treatment. Cisplatin is used to treat many different types of cancer, e.g. testicular, ovarian, melanoma, bladder, non-small cell lung cancer, small cell lung cancer, myelomas and lymphomas. READ MORE

  4. 4. Physicochemical and Structural Aspects of Nucleic Acids

    Author : Subhrangsu Chatterjee; Adolf Gogoll; Helena Grennberg; Göran Widmalm; Uppsala universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Organic chemistry; pKa; Hydrogen bonding; Stacking; NMR; MD; DNA; RNA; Pyrimidine; Organisk kemi;

    Abstract : 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. READ MORE

  5. 5. Aspects of Antisense and Antigene Chemistry of Oligonucleotides Tethered to Intercalators

    Author : Dimitri Ossipov; Jesper Wengel; Uppsala universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Bioorganic chemistry; oligonucleotides; intercalators; ruthenium complexes; RNase H cleavage; photocross-linkage; Bioorganisk kemi; Bioorganic chemistry; Bioorganisk kemi; bioorganisk kemi; Biorganic Chemistry;

    Abstract : Synthetic and physicochemical studies on appropriately functionalized ODN-conjugates have been performed to evaluate their abilities to act as antisense agents against RNA or as intramolecular DNA cross-linking agents. Intercalating aromatic systems [phenazine (Pnz), dipyridophenazine (DPPZ)] and metallointercalators such as Ru2+(phen)2(DPPZ) and Ru2+(tpy)(DPPZ)L [where L = chemically or photochemically labile ligand, phen = phenanthroline, tpy = terpyridine], which are covalently tethered to the oligo-deoxynucleotides (ODNs), have been chosen for this purpose. READ MORE