title: Development of site-specific artificial ribonucleases.
abstract: Recently we found that an antisense 2'-O-methyloligonucleotide, with two terpyridine*Cu(II) complexes at contiguous internal sites, was highly active as a site-specific (sequence-specific) artificial ribonuclease, with the activity derived from the cooperative action of the complexes. Two kinds of terpyridine-linked nucleosides were used for the construction of the RNA cleaver, including a uridine derivative with terpyridine attached to the 2'-oxygen via a short linker arm. In order to explore more efficient cleavers (practical cleavers), we have constructed a structurally similar cleaver (18-mer), but containing a novel 2'-carbon-branched uridine with a terpyridine group instead of the aforementioned 2'-oxygen-modified uridine. The reaction of a 10-fold excess of the target RNA 24-mer with the new agent, in the presence of Cu(II) ions, and at pH 7.5 and 37 degrees C, revealed that the substrate was cleaved in 92% yield after 5 h. Under similar conditions, the previous cleaver was less active and the cleavage yield was 61%.
authors.affiliation: Department of Applied and Bioapplied Chemistry, Graduate School of Engineering, Osaka City University, Sugimoto 3-3-138, Sumiyoshi-ku, Osaka 558-8585, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Takayama
authors.forename: Satoshi
authors.initials: S
authors.lastname: Sakamoto
authors.forename: Masaya
authors.initials: M
authors.lastname: Kitamura
authors.forename: Hideo
authors.initials: H
authors.lastname: Inoue
mesh_terms: D016376:Oligonucleotides, Antisense / Q000737:chemistry*; D009943:Organophosphorus Compounds / Q000138:chemical synthesis; D012260:Ribonucleases / Q000737:chemistry*; D014529:Uridine / Q000031:analogs & derivatives* / Q000737:chemistry
chemical_list: D016376:Oligonucleotides, Antisense; D009943:Organophosphorus Compounds; C434331:phosphoramidite; D012260:Ribonucleases; D014529:Uridine