BIOL 71 |
| The predictable self-assembly and the well-defined structures of DNA make hybrid materials consisting of nucleic acids and non-nucleosidic building blocks useful for the design of new functional materials and catalysts. A number of functionalized polyaza crown ethers were synthesized by a flexible convergent synthetic strategy which allows easy access to libraries of polyaza crown ethers . The appropriate functionalisation allows for a subsequent incorporation into oligonucleotides by automated DNA-synthesis with high coupling efficiency. Thermal duplex stability were investigated by UV-melting curve analysis which showed a remarkable stabilization of the resulting DNA duplexes when polyaza crown ethers with lipophilic substituents (e.g. palmityl) were incorporated in opposite positions anywhere in a sequence or as dangling ends. Polyaza crown ether modified oligonucleotides also form stable duplexes with unmodified complementary ssDNA and ssRNA. The mismatch discrimination power of corresponding duplexes has been investigated. The well-known ability of crown ethers to complex metal ions combined with the chirality of DNA duplexes make some of these hybrid materials candidates for use in asymmetric catalysis. The properties of polyaza crown ether modified oligonucleotides as catalysts in a copper(II)-catalyzed Diels-Alder reaction will be presented including effects of various DNA-conjugates (catalysts) on the stereochemical oucome (ee) of the reaction. Related polyaza crown ether modified oligonucleotides have shown potential as artificial RNAses by virtue of the copper-(II)-polyaza crown ether complex embedded in the DNA-conjugates. Results on the catalytic RNA cleavage activity of such systems will be presented. |
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Frontiers in Chemical Biology
5:00 PM-7:00 PM, Sunday, August 19, 2007 BCEC -- Exhibit Hall - B2, Poster
Division of Biological Chemistry |