title: Circular DNA by "Bis-Click" Ligation: Template-Independent Intramolecular Circularization of Oligonucleotides with Terminal Alkynyl Groups Utilizing Bifunctional Azides.
abstract: A highly effective and convenient "bis-click" strategy was developed for the template-independent circularization of single-stranded oligonucleotides by employing copper(I)-assisted azide-alkyne cycloaddition. Terminal triple bonds were incorporated at both ends of linear oligonucleotides. Alkynylated 7-deaza-2'-deoxyadenosine and 2'-deoxyuridine residues with different side chains were used in solid-phase synthesis with phosphoramidite chemistry. The bis-click ligation of linear 9- to 36-mer oligonucleotides with 1,4-bis(azidomethyl)benzene afforded circular DNA in a simple and selective way; azido modification of the oligonucleotide was not necessary. Short ethynyl side chains were compatible with the circularization of longer oligonucleotides, whereas octadiynyl residues were used for short 9-mers. Compared with linear duplexes, circular bis-click constructs exhibit a significantly increased duplex stability over their linear counterparts. The intramolecular bis-click ligation protocol is not limited to DNA, but may also be suitable for the construction of other macrocycles, such as circular RNAs, peptides, or polysaccharides.
authors.affiliation: Laboratory of Bioorganic Chemistry and Chemical Biology, Center for Nanotechnology, Heisenbergstrasse 11, 48149, Münster, Germany.|Laboratorium für Organische und Bioorganische Chemie, Institut für Chemie neuer Materialien, Universität Osnabrück, Barbarastrasse 7, 49069, Osnabrück, Germany), Fax: (+49) 251-53406857.
authors.forename: Haozhe
authors.initials: H
authors.lastname: Yang
authors.affiliation: Laboratory of Bioorganic Chemistry and Chemical Biology, Center for Nanotechnology, Heisenbergstrasse 11, 48149, Münster, Germany. frank.seela@uni-osnabrueck.de.|Laboratorium für Organische und Bioorganische Chemie, Institut für Chemie neuer Materialien, Universität Osnabrück, Barbarastrasse 7, 49069, Osnabrück, Germany), Fax: (+49) 251-53406857. frank.seela@uni-osnabrueck.de.
authors.forename: Frank
authors.initials: F
authors.lastname: Seela
mesh_terms: D000480:Alkynes / Q000737:chemistry*; D001386:Azides / Q000737:chemistry*; D020029:Base Pairing; D001555:Benzene Derivatives / Q000737:chemistry*; D057930:Click Chemistry; D003300:Copper / Q000737:chemistry; D061565:Cycloaddition Reaction; D004247:DNA / Q000737:chemistry*; D004270:DNA, Circular / Q000138:chemical synthesis* / Q000737:chemistry*; D003839:Deoxyadenosines / Q000737:chemistry*; D005456:Fluorescent Dyes / Q000737:chemistry*; D008026:Ligation; D009841:Oligonucleotides / Q000138:chemical synthesis / Q000737:chemistry*; D011134:Polysaccharides / Q000737:chemistry; D060327:Solid-Phase Synthesis Techniques; D014372:Tubercidin / Q000031:analogs & derivatives* / Q000737:chemistry
chemical_list: C000608606:1,4-bis(azidomethyl)benzene; D000480:Alkynes; D001386:Azides; D001555:Benzene Derivatives; D004270:DNA, Circular; D003839:Deoxyadenosines; D005456:Fluorescent Dyes; D009841:Oligonucleotides; D011134:Polysaccharides; C053222:2'-deoxytubercidin; D003300:Copper; D004247:DNA; D014372:Tubercidin
keywords: DNA; azides; circularization; click chemistry; synthesis design