Modification : 2'-O methyl bases
Catalog Reference Number
Molecular Weight (mw)
Extinction Coeficient (ec)
Technical Info (pdf)
Antisense Oligos (ODN) & siRNA Oligo Modifications
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2'-O-Methyl bases are classified as a 2'-O-Methyl RNA monomer. 2'-O-Methyl nucleotides are most commonly used to confer nuclease resistance to an oligo designed for anti-sense, siRNA or aptamer-based research, diagnostic or therapeutic purposes, when specific 2'-OH is not required. Nuclease resistance can be further enhanced by phosphorothiolation of appropriate internucleotide linkages within the oligo.
The hydrogen bonding behavior of a 2'-O-Methyl RNA/RNA base pair is closer to that of an RNA/RNA base pair than a DNA/RNA base pair. Consequently, the presence of 2'-O-Methyl nucleotides improves duplex stability. Indeed, incorporation of a 2'-O-Methyl nucleotide into an anti-sense oligo (resulting in a 2'-O-Methyl RNA/DNA chimeric), lead to a increase in the Tm of its duplex with RNA, relative to that formed by an unmodified anti-sense DNA oligo, of 1.3oC per 2'-O-Methyl RNA residue added (2). Moreover, from a synthesis standpoint, the coupling efficiency of 2'-O-Methyl phosphoramidites are higher than those of RNA monomers, resulting in higher yield of full-length oligos.
ASO's and siRNA Modifications.
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ASO's and siRNA Delivery.
The development of effective delivery systems for antisense oligonucleotides is essential for their clinical therapeutic application. The most common delivery system involves a relatively hydrophobic molecule that can cross the lipid membrane. Cholesterol TEG, alpha-Tocopherol TEG ( a natural isomer of vitamin E), stearyl and GalNAc modifications have been shown to effective for delivery of ASO's and siRNA in addition to cell penetrating peptides.
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1. Cotton, M.; Oberhauser, B.; Burnar, H. et al.
2'O methyl and 2'O ethyl oligoribonucleotides as inhibitors of the in vitro U7 snRNP-dependent messenger-RNA processing event. Nucleic Acids Res.
(1991) , 19
2. Kawasaki, A.M. et al.
, Uniformly modified 2'-deoxy-2'-fluoro phosphorothioate oligonucleotides as nuclease resistant antisense compounds with high affinity and specificity for RNA targets, Journal of Medicinal Chemistry
- 2'-O methyl bases