title: Self-assembling supramolecular complexes by single-stranded extension from plasmid DNA.
abstract: Self-assembling supramolecular complexes are of great interest for bottom-up research like nanotechnology. DNA is an inexpensive building block with sequence-specific self-assembling capabilities through Watson-Crick and/or Hoogsteen base pairing and could be used for applications in surface chemistry, material science, nanomechanics, nanoelectronics, nanorobotics, and of course in biology. The starting point is usually single-stranded DNA, which is rather easily accessible for base pairing and duplex formation. When long stretches of double-stranded DNA are desirable, serving either as genetic codes or electrical wires, bacterial expansion of plasmids is an inexpensive approach with scale-up properties. Here, we present a method for using double-stranded DNA of any sequence for generating simple structures, such as junctions and DNA lattices. It is known that supercoiled plasmids are strand-invaded by certain DNA analogs. Here we add to the complexity by using "Self-assembling UNiversal (SUN) anchors" formed by DNA analog oligonucleotides, synthesized with an extension, a "sticky-end" that can be used for further base pairing with single-stranded DNA. We show here how the same set of SUN anchors can be utilized for gene therapy, plasmid purification, junction for lattices, and plasmid dimerization through Watson-Crick base pairing. Using atomic force microscopy, it has been possible to characterize and quantify individual components of such supra-molecular complexes.
authors.affiliation: Clinical Research Center, Department of Laboratory Medicine, Karolinska Institutet, Karolinska University Hospital, SE-141 86 Stockholm, Sweden. Mathias.Svahn@ki.se
authors.forename: Mathias G
authors.initials: MG
authors.lastname: Svahn
authors.forename: Maroof
authors.initials: M
authors.lastname: Hasan
authors.forename: Valeria
authors.initials: V
authors.lastname: Sigot
authors.forename: Juan José
authors.initials: JJ
authors.lastname: Valle-Delgado
authors.forename: Mark W
authors.initials: MW
authors.lastname: Rutland
authors.forename: Karin E
authors.initials: KE
authors.lastname: Lundin
authors.forename: C I Edvard
authors.initials: CI
authors.lastname: Smith
mesh_terms: D000818:Animals; D020029:Base Pairing; D001483:Base Sequence; D004247:DNA / Q000737:chemistry*; D004277:DNA, Single-Stranded / Q000737:chemistry*; D019281:Dimerization; D051379:Mice; D018625:Microscopy, Atomic Force; D041681:NIH 3T3 Cells; D036103:Nanotechnology / Q000379:methods*; D009693:Nucleic Acid Hybridization; D009841:Oligonucleotides / Q000737:chemistry*; D010957:Plasmids / Q000737:chemistry*
chemical_list: D004277:DNA, Single-Stranded; D009841:Oligonucleotides; D004247:DNA