title: An NMR study of the conformation and thermodynamics of the circular dumbbell d [formula: see text] Slow exchange between two- and four-membered hairpin loops.
abstract: The circular DNA decamer 5'-d [formula: see text] 3' is studied in solution by means of NMR spectroscopy. At low temperature the molecule adopts a dumbbell structure with three Watson-Crick C-G base pairs and two two-residue loops in opposite parts of the molecule. On raising the temperature another conformer appears, in which the closing C-G base pair in the 5'-GTTC-3' loop is disrupted, whereas the opposite 5'-CTTG-3' loop remains stable. The two conformers are in slow equilibrium over a limited temperature range.
authors.affiliation: Department of Organic Chemistry, Leiden University, The Netherlands.
authors.forename: J H
authors.initials: JH
authors.lastname: Ippel
authors.forename: V
authors.initials: V
authors.lastname: Lanzotti
authors.forename: A
authors.initials: A
authors.lastname: Galeone
authors.forename: L
authors.initials: L
authors.lastname: Mayol
authors.forename: J E
authors.initials: JE
authors.lastname: van den Boogaart
authors.forename: J A
authors.initials: JA
authors.lastname: Pikkemaat
authors.forename: C
authors.initials: C
authors.lastname: Altona
mesh_terms: D001482:Base Composition; D001483:Base Sequence; D004270:DNA, Circular / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D009838:Oligodeoxyribonucleotides / Q000737:chemistry*; D011522:Protons; D013816:Thermodynamics
chemical_list: D004270:DNA, Circular; D009838:Oligodeoxyribonucleotides; D011522:Protons