Hybridization and Mismatch Discrimination Abilities of 2',4'-Bridged Nucleic Acids Bearing 2-Thiothymine or 2-Selenothymine Nucleobase.
Habuchi, T., Yamaguchi, T., Aoyama, H., Horiba, M., Ito, K.R., Obika, S.(2019) J Org Chem 84: 1430-1439
- PubMed: 30632750 
- DOI: https://doi.org/10.1021/acs.joc.8b02863
- Primary Citation of Related Structures:  
6ADV - PubMed Abstract: 
Oligonucleotides modified with 2'- O,4'- C-spirocyclopropylene-bridged nucleic acid (scpBNA) exhibit excellent duplex-forming ability with their complementary single-stranded RNA (ssRNA). Here, we demonstrate that scpBNA bearing a 2-thiothymine (scpBNA-S 2 T) or 2-selenothymine (scpBNA-Se 2 T) nucleobase provides robust mismatch discrimination capabilities to oligonucleotides without compromising their high binding affinities toward the full complementary ssRNA. X-ray crystallographic analysis of a self-assembling oligonucleotide featuring 2',4'-BNA/LNA-2-thiothymine (2',4'-BNA/LNA-S 2 T, where 2',4'-BNA and LNA stand for "2'- O,4'- C-methylene-bridged nucleic acid" and "locked nucleic acid", respectively), a prototype of scpBNA-S 2 T, revealed that the 2-thiocarbonyl moiety plays a crucial role in the destabilization of thymine-guanine mismatched wobble base pairs.
Organizational Affiliation: 
Graduate School of Pharmaceutical Sciences , Osaka University , 1-6 Yamadaoka , Suita , Osaka 565-0871 , Japan.