title: Development of a 3'-amino linker with high conjugation activity and its application to conveniently cross-link blunt ends of a duplex.
abstract: The 2-aminoethyl carbamate linker (ssH linker) exhibits high activity in modifying the 5'-termini of oligonucleotides; however, the ssH linker is not appropriate for 3'-terminal modification because it undergoes intramolecular trans-acylation under heat-aqueous ammonia conditions. We developed an N-(2-aminoethyl)carbamate linker (revH linker), in which the carbamate is oriented in the reverse direction relative to that in 2-aminoethyl carbamate. The revH linker was tolerant to heat-alkaline conditions and retained its high reactivity in conjugation with exogenous molecules. The 3'-revH linker was efficiently linked with the 5'-ssH linker at the termini of complementary double strands with a bifunctional molecule, producing a synthetic loop structure. An anti-microRNA oligonucleotide (AMO) was prepared from the chemical ligation of three-stranded 2'-O-methyl RNAs, and the AMO with two alkyl loops exhibited high inhibition activity toward miRNA function. The revH linker is not only useful for 3'-terminal modification of oligonucleotides but also expands the utility range in combination with the 5'-ssH linker.
authors.affiliation: Bioproduction Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), 2-17-2-1 Tsukisamu-Higashi, Toyohira-ku, Sapporo 062-8517, Japan.
authors.forename: Keiko
authors.initials: K
authors.lastname: Kowata
authors.affiliation: Biomedical Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), 1-1-1 Tsukuba Central 6, Higashi, Tsukuba-shi, Ibaraki 305-8566, Japan.
authors.forename: Naoshi
authors.initials: N
authors.lastname: Kojima
authors.affiliation: Bioproduction Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), 2-17-2-1 Tsukisamu-Higashi, Toyohira-ku, Sapporo 062-8517, Japan. Electronic address: komatsu-yasuo@aist.go.jp.
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Komatsu
mesh_terms: D002219:Carbamates / Q000737:chemistry*; D009841:Oligonucleotides / Q000737:chemistry*
chemical_list: D002219:Carbamates; D009841:Oligonucleotides
keywords: Amino linker; Cross-link; Labeling; Nucleic acids; Oligonucleotides; anti-microRNA