title: Unraveling the Thermodynamics of the Folding and Interconversion of Human Telomere G-Quadruplexes.
abstract: Why human telomere DNA fragments fold into different G-quadruplex structures with parallel, hybrid, and antiparallel strand orientations depending on the temperature and concentration of co-solutes remains poorly understood. Similarly, the formation of intermediate structures along the folding or interconversion pathways is not well understood. Herein, we address these questions by introducing a conceptual framework, based on the global thermodynamic analysis of DSC and CD spectroscopy data, which led to a detailed description of the topological phase space (phase diagram) of the stability of the human telomere fragment 5'-AGGG(TTAGGG)3 -3' (Tel22). This framework clarifies the driving forces of quadruplex folding and interconversion processes over a wide range of temperatures and ion (K(+) , Na(+) ) and polyethylene glycol (PEG) concentrations and demonstrates their linkage to the human telomere DNA structural features.
authors.affiliation: Faculty of Chemistry and Chemical Technology, University of Ljubljana, Večna pot 113, Ljubljana, Slovenia.
authors.forename: Matjaž
authors.initials: M
authors.lastname: Bončina
authors.affiliation: Faculty of Chemistry and Chemical Technology, University of Ljubljana, Večna pot 113, Ljubljana, Slovenia.
authors.forename: Gorazd
authors.initials: G
authors.lastname: Vesnaver
authors.affiliation: James Graham Brown Cancer Center, University of Louisville, 505 S. Hancock St., Louisville, KY, 40202, USA. j.chaires@louisville.edu.
authors.forename: Jonathan Brad
authors.initials: JB
authors.lastname: Chaires
authors.affiliation: Faculty of Chemistry and Chemical Technology, University of Ljubljana, Večna pot 113, Ljubljana, Slovenia. jurij.lah@fkkt.uni-lj.si.
authors.forename: Jurij
authors.identifier: 0000-0003-1021-3803
authors.initials: J
authors.lastname: Lah
mesh_terms: D002152:Calorimetry, Differential Scanning; D002942:Circular Dichroism; D004247:DNA / Q000737:chemistry*; D054856:G-Quadruplexes; D006801:Humans; D016615:Telomere; D013816:Thermodynamics
chemical_list: D004247:DNA
keywords: DNA structures; G-quadruplexes; differential scanning calorimetry; human telomere repeat; thermodynamics