Properties of mixed backbone oligonucleotides containing 3′-O-methyl ribonucleosides

Oligonucleotides containing 3′-O-methyl ribonucleosides were synthesized, and their thermal stabilities and global conformations with RNA and DNA have been studied. The duplexes displayed lower Tm values as compared to the unmodified ones, and adopted A-conformations. Furthermore, they are not a substrate for RNase H, are slightly resistant to snake venom phosphodiesterase, and are not cleaved by nuclease S 1