title: Zwitterionic oligonucleotides: a study on binding properties of 2'-O-aminohexyl modifications.
abstract: 2'-O-Aminohexyl side chains provide excellent conditions for zwitterionic interstrand and intrastrand interactions of oligonucleotides. 2'-O-Aminoalkylated phosphoramidites of adenosine and uridine were synthesized and incorporated in increasing number into homo adenosine and homo uridine/thymidine dodecamers, respectively. CD spectra of these dodecamers with complementary sense DNA exhibited a B-DNA type structure. While duplex stability values of all tested oligonucleotides were lower than those of the native oligonucleotides, they were significantly higher than those of 2'-O-heptyl modified oligonucleotides. The destabilization amounted to 0.9, 1.5, and 2.7 degrees C per modification for 2'-O-aminohexyl adenosine, 2'-O-aminohexyl uridine, and 2'-O-heptyl adenosine substitutions. These findings are pointing to a duplex stabilizing effect of the interaction of side chain amino groups with backbone phosphoric acid.
authors.affiliation: Department für Medizinische/Pharmazeutische Chemie, Universität Wien, Pharmaziezentrum, Althanstrasse 14, Wien 1090, Austria. christian.noe@univie.ac.at
authors.forename: Christian R
authors.initials: CR
authors.lastname: Noe
authors.forename: Johannes
authors.initials: J
authors.lastname: Winkler
authors.forename: Ernst
authors.initials: E
authors.lastname: Urban
authors.forename: Matthias
authors.initials: M
authors.lastname: Gilbert
authors.forename: Georg
authors.initials: G
authors.lastname: Haberhauer
authors.forename: Helmut
authors.initials: H
authors.lastname: Brunar
mesh_terms: D000588:Amines / Q000138:chemical synthesis / Q000737:chemistry*; D020029:Base Pairing; D002942:Circular Dichroism; D009693:Nucleic Acid Hybridization; D009711:Nucleotides / Q000737:chemistry*; D009838:Oligodeoxyribonucleotides / Q000138:chemical synthesis / Q000737:chemistry*
chemical_list: D000588:Amines; D009711:Nucleotides; D009838:Oligodeoxyribonucleotides