Physikalische Chemie I - Biophysikalische Chemie, Fakultät für Chemie und Chemische Biologie, TU Dortmund, Otto-Hahn Str. 4a, 44227, Dortmund, Germany.
Angew Chem Int Ed Engl. 2017 Apr 24;56(18):5045-5049. doi: 10.1002/anie.201701420. Epub 2017 Apr 5.
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.
采用单分子Förster 共振能量转移和荧光相关光谱法，在环境和极端环境条件（包括高压和高温）下，研究了 DNA 发夹（Hp）在没有和存在两种天然渗透调节剂三甲基氧化胺（TMAO）和脲的情况下的结构动力学。在单分子水平上研究了压力对 DNA Hp 构象动力学的影响，为其构象转换提供了新的机制见解。与具有相似熔点的典型 DNA 双螺旋结构不同，发现 DNA Hp 对压力相当敏感。结合温度和压力相关数据，可以将折叠自由能分解为焓、熵和体积贡献。相容的渗透调节剂 TMAO 不仅在高温下，而且在高压下和存在去稳定共溶质脲时，有效地稳定了折叠构象。
