Highly Stable DNA Triplexes Formed with Cationic Phosphoramidate Pyrimidine α-Oligonucleotides
| Autor: | Françoise Debart, Frédéric Heitz, Jean-Jacques Vasseur, Thibaut Michel |
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| Rok vydání: | 2005 |
| Předmět: |
Circular dichroism
Ultraviolet Rays Molecular Sequence Data Hoogsteen base pair Oligonucleotides Biochemistry Organic chemistry Phosphoric Acids A-DNA Molecular Biology Magnesium ion Base Sequence Chemistry Oligonucleotide Circular Dichroism Organic Chemistry Temperature Cationic polymerization Phosphoramidate DNA Hydrogen-Ion Concentration Amides Crystallography Pyrimidines Models Chemical Phosphodiester bond Nucleic Acid Conformation Molecular Medicine |
| Zdroj: | ChemBioChem. 6:1254-1262 |
| ISSN: | 1439-4227 |
| DOI: | 10.1002/cbic.200400436 |
| Popis: | The ability of cationic phosphoramidate pyrimidine alpha-oligonucleotides (ONs) to form triplexes with DNA duplexes was investigated by UV melting experiments, circular dichroism spectroscopy and gel mobility shift experiments. Replacement of the phosphodiester linkages in alpha-ONs with positively charged phosphoramidate linkages results in more efficient triplex formation, the triplex stability increasing with the number of positive charges. At a neutral pH and in the absence of magnesium ions, it was found that a fully cationic phosphoramidate alpha-TFO (triplex-forming oligonucleotide) forms a highly stable triplex that melts at a higher temperature than the duplex target. No hysteresis between the annealing and melting curves was noticed; this indicates fast association. Moreover, the recognition of a DNA duplex with a cationic alpha-TFO through Hoogsteen base pairing is highly sequence-specific. To the best of our knowledge, this is the first report of stable triplexes in the pyrimidine motif formed by cationic alpha-oligonucleotides and duplex targets. |
| Databáze: | OpenAIRE |
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