title: Efficient procedure of preparation and properties of long uniform G4-DNA nanowires.
abstract: Here we describe a novel and efficient procedure for preparation of long uniform G4-DNA wires. The procedure includes (i) enzymatic synthesis of double-stranded DNA molecules consisting of long (up to 10,000 bases), continuous G strands and chains of complementary (dC)20-oligonucleotides, poly(dG)-n(dC)20; (ii) size exclusion HPLC separation of the G strands from the (dC)20 oligonucleotides in 0.1M NaOH; and (iii) folding of the purified G strands into G4-DNA structures by lowering the pH to 7.0. We show by atomic force microscopy (AFM) that the preparation procedure yielded G4-DNA wires with a uniform morphology and a narrow length distribution. The correlation between the total amount of nucleotides in the G strands and the contour length of the G4-DNA molecules estimated by AFM suggests monomolecular folding of the G strands into quadruplex structures. The folding takes place either in the presence or in the absence of stabilizing ions (K+ or Na+). The addition of these cations leads to a dramatic change in the circular dichroism spectrum of the G4-DNA.
authors.affiliation: Department of Biochemistry, George S. Wise Faculty of Life Sciences, Tel Aviv University, Aviv 69978, Israel.
authors.forename: Natalia
authors.initials: N
authors.lastname: Borovok
authors.forename: Tatiana
authors.initials: T
authors.lastname: Molotsky
authors.forename: Jamal
authors.initials: J
authors.lastname: Ghabboun
authors.forename: Danny
authors.initials: D
authors.lastname: Porath
authors.forename: Alexander
authors.initials: A
authors.lastname: Kotlyar
mesh_terms: D002851:Chromatography, High Pressure Liquid; D004247:DNA; D004256:DNA Polymerase I / Q000378:metabolism; D054856:G-Quadruplexes; D018625:Microscopy, Atomic Force; D053770:Nanowires; D011068:Poly G / Q000096:biosynthesis / Q000302:isolation & purification
chemical_list: D011068:Poly G; C026628:poly(dG); D004247:DNA; D004256:DNA Polymerase I