title: Liquid Crystal Ordering and Isotropic Gelation in Solutions of Four-Base-Long DNA Oligomers.
abstract: Liquid crystal ordering is reported in aqueous solutions of the oligomer 5'-ATTAp-3' and of the oligomer 5'-GCCGp-3'. In both systems, we quantitatively interpret ordering as stemming from the chaining of molecules via a "running-bond" type of pairing, a self-assembly process distinct from the duplex aggregation previously reported for longer oligonucleotides. While concentrated solutions of 5'-ATTAp-3' show only a columnar liquid crystal phase, solutions of 5'-GCCGp-3' display a rich phase diagram, featuring a chiral nematic phase analogous to those observed in solutions of longer oligonucleotides and two unconventional phases, a columnar crystal and, at high concentration, an isotropic amorphous gel. The appearance of these phases, which can be interpreted on the basis of features of 5'-GCCGp-3'molecular structure, suggests distinctive assembly motifs specific to ultrashort oligonucleotides.
authors: Dipartimento di Biotecnologie Mediche e Medicina Traslazionale, Università di Milano , via Fratelli Cervi 93, I-20090 Segrate (Milan), Italy.|Dipartimento di Scienze Umane e Promozione della Qualità della Vita, Università San Raffaele di Roma , via di Val Cannuta, 247, I-00166 Rome, Italy.
authors: Tommaso P
authors: TP
authors: Fraccia
authors: Department of Physics and Liquid Crystal Materials Research Center, University of Colorado , Boulder, Colorado 80309-0390, United States.
authors: Gregory P
authors: GP
authors: Smith
authors: NOXXON Pharma AG, Max-Dohrn-Strasse 8-10, 10589 Berlin, Germany.
authors: Lucas
authors: L
authors: Bethge
authors: Dipartimento di Biotecnologie Mediche e Medicina Traslazionale, Università di Milano , via Fratelli Cervi 93, I-20090 Segrate (Milan), Italy.
authors: Giuliano
authors: G
authors: Zanchetta
authors: Dipartimento di Biotecnologie Mediche e Medicina Traslazionale, Università di Milano , via Fratelli Cervi 93, I-20090 Segrate (Milan), Italy.
authors: Giovanni
authors: G
authors: Nava
authors: NOXXON Pharma AG, Max-Dohrn-Strasse 8-10, 10589 Berlin, Germany.
authors: Sven
authors: S
authors: Klussmann
authors: Department of Physics and Liquid Crystal Materials Research Center, University of Colorado , Boulder, Colorado 80309-0390, United States.
authors: Noel A
authors: NA
authors: Clark
authors: Dipartimento di Biotecnologie Mediche e Medicina Traslazionale, Università di Milano , via Fratelli Cervi 93, I-20090 Segrate (Milan), Italy.
authors: Tommaso
authors: T
authors: Bellini
mesh_terms: D004247:DNA / Q000737:chemistry*; D050866:Liquid Crystals; D015394:Molecular Structure; D009841:Oligonucleotides
chemical_list: D009841:Oligonucleotides; D004247:DNA
keywords: DNA nanotechnology; coaxial stacking of DNA; liquid crystals; origin of life; self-assembly