title: 2'-O-[2-(guanidinium)ethyl]-modified oligonucleotides: stabilizing effect on duplex and triplex structures.
abstract: [structure: see text] Oligonucleotides with a novel 2'-O-[2-(guanidinium)ethyl] (2'-O-GE) modification have been synthesized using a novel protecting group strategy for the guanidinium group. This modification enhances the binding affinity of oligonucleotides to RNA as well as duplex DNA (DeltaT(m) 3.2 degrees C per modification). The 2'-O-GE modified oligonucleotides exhibited exceptional resistance to nuclease degradation. The crystal structure of a palindromic duplex formed by a DNA oligonucleotide with a single 2'-O-GE modification was solved at 1.16 A resolution.
authors.affiliation: Department of Medicinal Chemistry, Isis Pharmaceuticals, Inc., Carlsbad, California 92008, USA.
authors.forename: Thazha P
authors.initials: TP
authors.lastname: Prakash
authors.forename: Ask
authors.initials: A
authors.lastname: Püschl
authors.forename: Elena
authors.initials: E
authors.lastname: Lesnik
authors.forename: Venkatraman
authors.initials: V
authors.lastname: Mohan
authors.forename: Valentina
authors.initials: V
authors.lastname: Tereshko
authors.forename: Martin
authors.initials: M
authors.lastname: Egli
authors.forename: Muthiah
authors.initials: M
authors.lastname: Manoharan
mesh_terms: D004247:DNA / Q000737:chemistry*; D018076:DNA, Complementary / Q000737:chemistry; D019791:Guanidine / Q000737:chemistry*; D008958:Models, Molecular; D009690:Nucleic Acid Conformation; D009841:Oligonucleotides / Q000138:chemical synthesis / Q000737:chemistry*; D012313:RNA / Q000737:chemistry*; D018075:RNA, Complementary / Q000737:chemistry; D013997:Time Factors
chemical_list: D018076:DNA, Complementary; D009841:Oligonucleotides; D018075:RNA, Complementary; D012313:RNA; D004247:DNA; D019791:Guanidine