Synthesis and base-pairing properties of the nuclease-resistant alpha-anomeric dodecaribonucleotide alpha-[r(UCUUAACCCACA)].
The non natural oligoribonucleotide alpha-[r(UCUUAACCCACA)] consisting exclusively of alpha-anomeric ribonucleoside units was synthesized according to the phosphoramidite methodology and the solid support technology. For this purpose, the base-protected alpha-ribonucleosides were synthesized and converted into their O-methylphosphoramidites. Assembling was carried out on a DNA synthesizer with an average efficiency of 97% per step. Base composition of this nuclease-resistant alpha-RNA strand was ascertained after chemical and enzymatic hydrolysis and HPLC analysis of the hydrolysate. Whereas no spectroscopic evidence of base pairing was found above 0 degrees C between alpha-[r(UCUUAACCCACA)] and beta-[d(TGTGGGTTAAGA)], a clear UV absorbance transition (Tm 25.5 degrees C) was observed during the hybridization of the same alpha-RNA strand with beta-[d(AGAATTGGGTGT)]. In this latter case, the mixing curve titration suggests formation at low temperature of a triplex involving two alpha-RNA and one beta-DNA strands. Moreover, this alpha-decaribonucleotide complementary in parallel orientation of the splice receptor of HIV-1 tat mRNA was found to inhibit (10 microM less than ED50 less than 20 microM), with apparent lack of sequence specificity, the de novo HIV-1 infection in cultured cells.
Laboratoire de Chimie Bio-organique, UA 488 CNRS, Université Montpellier II, France.
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Debart
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Rayner
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Degols
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Imbach
D001482:Base Composition; D001483:Base Sequence; D002851:Chromatography, High Pressure Liquid; D004247:DNA; D015497:HIV-1 / Q000187:drug effects / Q000502:physiology; D006801:Humans; D008969:Molecular Sequence Data; D009693:Nucleic Acid Hybridization; D009843:Oligoribonucleotides / Q000138:chemical synthesis* / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology; D012313:RNA; D012260:Ribonucleases / Q000378:metabolism; D013696:Temperature; D014407:Tumor Cells, Cultured; D014779:Virus Replication / Q000187:drug effects
D009843:Oligoribonucleotides; D012313:RNA; D004247:DNA; D012260:Ribonucleases