title: [Synthesis and properties of mixed ribodeoxyribooligonucleotide duplexes containing an internucleotide trisubstituted pyrophosphate bond].
abstract: Fragments of double-stranded RNAs and mixed double-stranded ribo/deoxyribooligonucleotides containing an internucleotide trisubstituted pyrophosphate bond in a predetermined position of the sugar-phosphate backbone were synthesized. The modified internucleotide bond was created between synthetic oligonucleotides by chemical ligation with carbodiimide. The chemical ligation conditions were optimized for a series of duplexes that differed in the content and mutual arrangement of ribo- and deoxyribonucleotide blocks. The yield of oligonucleotides containing the trisubstituted internucleotide pyrophosphate bond was 90% in an all-deoxy duplex and 15-68% in ribooligonucleotide-containing duplexes. The modified duplexes thus obtained are relatively stable in an aqueous solution at pH 5.5-7.5, whereas the modified internucleotide bond is cleaved by amines to form phosphamide derivatives of the corresponding oligonucleotides. Automated solid-phase synthesis of oligonucleotide 3'-ethylphosphates is described.
authors.forename: N A
authors.initials: NA
authors.lastname: Naryshkin
authors.forename: M G
authors.initials: MG
authors.lastname: Ivanovskaia
authors.forename: T S
authors.initials: TS
authors.lastname: Oretskaia
authors.forename: E M
authors.initials: EM
authors.lastname: Volkov
authors.forename: M J
authors.initials: MJ
authors.lastname: Gait
authors.forename: Z A
authors.initials: ZA
authors.lastname: Shabarova
mesh_terms: D001483:Base Sequence; D003854:Deoxyribonucleotides / Q000138:chemical synthesis*; D011756:Diphosphates / Q000737:chemistry*; D008969:Molecular Sequence Data; D009838:Oligodeoxyribonucleotides / Q000138:chemical synthesis*; D012330:RNA, Double-Stranded / Q000138:chemical synthesis*
chemical_list: D003854:Deoxyribonucleotides; D011756:Diphosphates; D009838:Oligodeoxyribonucleotides; D012330:RNA, Double-Stranded