title: Osmolyte Effects on the Conformational Dynamics of a DNA Hairpin at Ambient and Extreme Environmental Conditions.
abstract: The structural dynamics of a DNA hairpin (Hp) are studied in the absence and presence of the two natural osmolytes trimethylamine-N-oxide (TMAO) and urea at ambient and extreme environmental conditions, including high pressures and high temperatures, by using single-molecule Förster resonance energy transfer and fluorescence correlation spectroscopy. The effect of pressure on the conformational dynamics of the DNA Hp is investigated on a single-molecule level, providing novel mechanistic insights into its conformational conversions. Different from canonical DNA duplex structures of similar melting points, the DNA Hp is found to be rather pressure sensitive. The combined temperature and pressure dependent data allow dissection of the folding free energy into its enthalpic, entropic, and volumetric contributions. The folded conformation is effectively stabilized by the compatible osmolyte TMAO not only at high temperatures, but also at high pressures and in the presence of the destabilizing co-solute urea.
authors.affiliation: Physikalische Chemie I - Biophysikalische Chemie, Fakultät für Chemie und Chemische Biologie, TU Dortmund, Otto-Hahn Str. 4a, 44227, Dortmund, Germany.
authors.forename: Satyajit
authors.initials: S
authors.lastname: Patra
authors.affiliation: Physikalische Chemie I - Biophysikalische Chemie, Fakultät für Chemie und Chemische Biologie, TU Dortmund, Otto-Hahn Str. 4a, 44227, Dortmund, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Anders
authors.affiliation: Physikalische Chemie I - Biophysikalische Chemie, Fakultät für Chemie und Chemische Biologie, TU Dortmund, Otto-Hahn Str. 4a, 44227, Dortmund, Germany.
authors.forename: Nelli
authors.initials: N
authors.lastname: Erwin
authors.affiliation: Physikalische Chemie I - Biophysikalische Chemie, Fakultät für Chemie und Chemische Biologie, TU Dortmund, Otto-Hahn Str. 4a, 44227, Dortmund, Germany.
authors.forename: Roland
authors.initials: R
authors.lastname: Winter
mesh_terms: D004247:DNA / Q000737:chemistry*; D031541:Fluorescence Resonance Energy Transfer; D006358:Hot Temperature; D008744:Methylamines / Q000737:chemistry*; D009690:Nucleic Acid Conformation; D009994:Osmolar Concentration; D011312:Pressure; D013816:Thermodynamics; D014508:Urea / Q000737:chemistry*
chemical_list: D008744:Methylamines; D014508:Urea; D004247:DNA; C005855:trimethyloxamine
keywords: DNA hairpin; fluorescence correlation spectroscopy; high pressure; osmolyte; smFRET