title: Phosphoramidate Ligation of Oligonucleotides in Nanoscale Structures.
abstract: The folding of long DNA strands into designed nanostructures has evolved into an art. Being based on linear chains only, the resulting nanostructures cannot readily be transformed into covalently linked frameworks. Covalently linking strands in the context of folded DNA structures requires a robust method that avoids sterically demanding reagents or enzymes. Here we report chemical ligation of the 3'-amino termini of oligonucleotides and 5'-phosphorylated partner strands in templated reactions that produce phosphoramidate linkages. These reactions produce inter-nucleotide linkages that are isoelectronic and largely isosteric to phosphodiesters. Ligations were performed at three levels of complexity, including the extension of branched DNA hybrids and the ligation of six scaffold strands in a small origami.
authors.affiliation: Institut für Organische Chemie, Universität Stuttgart, 70569, Stuttgart, Germany.
authors.forename: Matthäus
authors.initials: M
authors.lastname: Kalinowski
authors.affiliation: Institut für Organische Chemie, Universität Stuttgart, 70569, Stuttgart, Germany.
authors.forename: Rüdiger
authors.initials: R
authors.lastname: Haug
authors.affiliation: Institut für Organische Chemie, Universität Stuttgart, 70569, Stuttgart, Germany.
authors.forename: Hassan
authors.initials: H
authors.lastname: Said
authors.affiliation: Institut für Organische Chemie, Universität Stuttgart, 70569, Stuttgart, Germany.
authors.forename: Sylwia
authors.initials: S
authors.lastname: Piasecka
authors.affiliation: Institut für Organische Chemie, Universität Stuttgart, 70569, Stuttgart, Germany.
authors.forename: Markus
authors.initials: M
authors.lastname: Kramer
authors.affiliation: Institut für Organische Chemie, Universität Stuttgart, 70569, Stuttgart, Germany. lehrstuhl-2@oc.uni-stuttgart.de.
authors.forename: Clemens
authors.initials: C
authors.lastname: Richert
mesh_terms: D000577:Amides / Q000737:chemistry*; D002234:Carbodiimides / Q000737:chemistry; D049329:Nanostructures / Q000737:chemistry*; D009690:Nucleic Acid Conformation; D009693:Nucleic Acid Hybridization; D009841:Oligonucleotides / Q000737:chemistry*; D010756:Phosphoric Acids / Q000737:chemistry*; D034741:RNA, Small Interfering / Q000737:chemistry
chemical_list: C518491:1-ethyl-3-(3-(diethylamino)propyl)carbodiimide; D000577:Amides; D002234:Carbodiimides; D009841:Oligonucleotides; D010756:Phosphoric Acids; D034741:RNA, Small Interfering; C011067:phosphoramidic acid
keywords: DNA structures; ligation; nanostructures; nucleotide binding; oligonucleotides; triplex