Comparative activity of alpha- and beta-anomeric oligonucleotides on rabbit beta globin synthesis: inhibitory effect of cap targeted alpha-oligonucleotides.

Alpha-anomeric oligonucleotides are resistant to nucleases and display parallel annealing to RNA complementary sequences. We compared the effect of alpha- and beta-oligonucleotides targeted against various mRNA regions on the rabbit beta globin in vitro synthesis. In order to determine the role of RNase H, experiments were performed in both rabbit reticulocyte lysate and wheat germ extract. As expected beta-oligonucleotides were found more efficient in wheat germ extract which is rich in RNase H activity and alpha-oligonucleotide targeted against the initiation codon or downstream had no effect because they do not induce mRNA cleavage by RNase H. However, we report, for the first time, a specific translation inhibition by alpha-oligonucleotides. This occurs provided they are targeted against the cap region in 5' of the mRNA.