Open AccessSynthesis and base-pairing properties of the nuclease-resistant α-anomeric dodecaribonucleotide α-[r(UCUUAACCCACA)]
Author(s) -
Françoise Debart,
Bernard Rayner,
Geneviève Degols,
Jean−Louis Imbach
Publication year - 1992
Publication title -
nucleic acids research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 9.008
H-Index - 537
eISSN - 1362-4954
pISSN - 0305-1048
DOI - 10.1093/nar/20.6.1193
Subject(s) - biology , anomer , base pair , rna , microbiology and biotechnology , dna , nuclease , rnase h , ribonucleoside , phosphoramidite , stereochemistry , biochemistry , oligonucleotide , rnase p , chemistry , gene
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.