Ethidium and azidoethidium oligonucleotide derivatives: Synthesis,complementary complex formation and sequence-specific photomodification of the single-stranded and double-stranded target oligo- and polynucleotides |
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Authors: | A A Koshkin K Yu Kropachev S V Mamaev N V Bulychev S G Lokhov V V Vlassov A V Lebedev |
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Abstract: | Oligodeoxyribonucleotide derivatives containing ethidium or azidoethidium residues attached to 3′ and/or 5′ end were prepared. These derivatives formed tight specific complexes with complementary oligodeoxyribonucleotides where each attached ethidium residue led to an increase of complex Tm by 20–30°C. Tandem complexes of two oligodeoxyribonucleotides containing ethidium residues with an oligodeoxyribonucleotide having two adjacent complementary sequences for these Oligonucleotide were investigated. Photoinduced reactions of a number of ethidium and azidoethidium oligodeoxyribonucleotide derivatives with target complementary single-stranded and double-stranded oligo- and polydeoxyribonucleotides were investigated. The irradiation led to direct photocleavage of the target oligo- or polynucleotide, to formation of hidden (piperidine cleavable) modifications of the target of formation of covalent adducts between ethidium oligodeoxyribonucleotide derivative and the target. In a number of experiments, azidoethidium dyes were demonstrated to be considerably stronger photosensitizers than ethidium ones. Depending on the nature of the target (single- or double-stranded DNA) and on the irradiation conditions, the total damages to the target oligo- or polydeoxyribonucleotides ranged from 10–70% (for ethidium dyes) to 30–80% (for azidoethidium dyes). |
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Keywords: | Sequence-specific photomodification Oligonucleotide derivatives Ethidium Azidoethidium |
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