title: Synthesis of a carboxamide linked T*T dimer and its incorporation in oligonucleotides.
abstract: The condensation of 5'-O-protected 3'-O-(2-aminoethyl)thymidine with 1,2-dideoxy-1-thyminyl-beta-D-erythro-pentofuranuronic acid gives a T*T dimer with * representing a 3'-OCH2CH2NHC(O)-4' linkage connecting the two pentofuranosyl moieties. The incorporation of this dimer in oligonucleotide sequences show only moderately lowered Tm values when hybridized with a complementary DNA relative to the unmodified DNA duplex. Consistently, no looped-out or bubble-type structure could be detected in DNA duplexes with an internal T*T module. Moreover, the 5-atom carboxamide linker causes complete stop on DNA polymerization and on exonuclease III degradation.
authors.affiliation: Department of Chemistry, Odense University, Denmark.
authors.forename: A
authors.initials: A
authors.lastname: Chur
authors.forename: B
authors.initials: B
authors.lastname: Holst
authors.forename: O
authors.initials: O
authors.lastname: Dahl
authors.forename: P
authors.initials: P
authors.lastname: Valentin-Hansen
authors.forename: E B
authors.initials: EB
authors.lastname: Pedersen
mesh_terms: D001483:Base Sequence; D004259:DNA-Directed DNA Polymerase / Q000378:metabolism; D009682:Magnetic Resonance Spectroscopy; D008969:Molecular Sequence Data; D009838:Oligodeoxyribonucleotides / Q000138:chemical synthesis / Q000737:chemistry*; D011740:Pyrimidine Dimers / Q000737:chemistry*; D013941:Thymine / Q000737:chemistry
chemical_list: D009838:Oligodeoxyribonucleotides; D011740:Pyrimidine Dimers; D004259:DNA-Directed DNA Polymerase; D013941:Thymine