3′-MODIFIED OLIGO(2′-O-METHYLRIBONUCLEOTIDES) AS IMPROVED PROBES FOR HYBRIDIZATION WITH RNA

Abstract

A series of octa(2′-O-methylribonucleotides) with an additional 3′-terminal deoxynucleoside (T, dC, dA or dG) linked by the 3′-3′ (“inverted”) bond was synthesized. The exceptional stability of these oligomers to a 3′-exonuclease (SVP) and nucleases in culture medium containing 10% heat-inactivated fetal calf serum was demonstrated. It was shown that the addition of the 3′-dangling inverted deoxynucleoside increases substantially the thermal stability of the duplexes of oligo(2′-O-methylribonucleotides) with complementary RNA and DNA in the case of a relatively weak terminal A^mU(T) pair and enhances the mismatch sensitivity.

Keywords:

• Oligo(2′-O-methylribonucleotides)
• 3′-Dangling “Inverted” Deoxyribonucleoside
• Nuclease Resistance
• Duplex Stability