title: (2'-5')-Oligo-3'-deoxynucleotides: selective binding to single-stranded RNA but not DNA.
abstract: Oligodeoxynucleotides with (2'-5') internucleotide linkages have been synthesized on a solid support via standard cyanoethyl phosphoramidite chemistry. This simple change in the oligonucleotide bond connectivity led to unique properties. UV melting temperature experiments indicate that the (2'-5')-oligo-3'-deoxyadenylates, (2'-5')-3'-dA8 and (2'-5')-3'-dA8(s) phosphorothioate, hybridize selectively to single-stranded RNA but not DNA. The complex (2'-5')-3'-dA8:poly (U) (Tm = 32 degrees C) was nearly as stable as the natural (3'-5')-2'-dA8 and poly (U) (Tm = 33 degrees C) in 130 mM NaCl, and 10 mM phosphate buffer (pH 7.5). However, no association was observed upon mixing (2'-5')-3'-dA8 and poly (dT). The (2'-5') linkages also confer greater resistance to exo- and endonucleolytic degradation compared with (3'-5')-linked oligomers. The rate of degradation of (2'-5')-3'-dA8 was almost four times less than that of (3'-5')-2'-dA8 in cell culture medium containing 10% heat-inactivated fetal calf serum. An increase in stability for (2'-5')-3'-dA8 against endonuclease activity was observed in both cytoplasmic and nuclear extracts. The nucleic acid selectivity of (2'-5')-oligo-3'-deoxynucleotides may represent an important design feature to improve the efficacy of antisense oligonucleotides.
authors.affiliation: Dyad Pharmaceutical Corporation, Columbia, MD 21046, USA.
authors.forename: R
authors.initials: R
authors.lastname: Alul
authors.forename: G D
authors.initials: GD
authors.lastname: Hoke
mesh_terms: D000577:Amides; D000818:Animals; D002417:Cattle; D002460:Cell Line; D002467:Cell Nucleus / Q000187:drug effects / Q000378:metabolism; D003593:Cytoplasm / Q000378:metabolism; D004277:DNA, Single-Stranded / Q000737:chemistry* / Q000378:metabolism; D005092:Exonucleases / Q000097:blood / Q000378:metabolism; D005347:Fibroblasts / Q000187:drug effects / Q000378:metabolism; D006801:Humans; D007202:Indicators and Reagents; D008297:Male; D009690:Nucleic Acid Conformation; D009691:Nucleic Acid Denaturation; D009838:Oligodeoxyribonucleotides / Q000138:chemical synthesis / Q000737:chemistry* / Q000494:pharmacology*; D010756:Phosphoric Acids; D011071:Poly T / Q000737:chemistry; D011072:Poly U / Q000737:chemistry; D012313:RNA / Q000737:chemistry* / Q000378:metabolism; D012867:Skin; D013056:Spectrophotometry, Ultraviolet; D013329:Structure-Activity Relationship; D013816:Thermodynamics; D013873:Thionucleotides
chemical_list: D000577:Amides; D004277:DNA, Single-Stranded; D007202:Indicators and Reagents; D009838:Oligodeoxyribonucleotides; D010756:Phosphoric Acids; D013873:Thionucleotides; D011071:Poly T; D011072:Poly U; D012313:RNA; C011067:phosphoramidic acid; D005092:Exonucleases