观察到在双链 DNA 弥散颗粒中有三个“重入”扭曲结构。
Observations of three "re-entrant" twisted structures in double-stranded DNA dispersion particles.
机构信息
Engelhardt Institute of Molecular Biology of the Russian Academy of Sciences, Vavilova st. 32, Moscow, Russia, 119991.
Landau Institute for Theoretical Physics of the Russian Academy of Sciences, academician Semenov ave. 1-A, Chernogolovka, Moscow Region, Russia, 142432.
出版信息
Eur Biophys J. 2022 Jan;51(1):85-94. doi: 10.1007/s00249-021-01578-6. Epub 2021 Nov 28.
In this work we report on observations of new twisted (cholesteric-like) structures in liquid-crystalline dispersion particles with a hexagonal packing of double-stranded (ds) DNA molecules. Heating up to 80 °C of the DNA dispersion formed in a aqueous-salt solution with a high osmotic pressure (concentration) of poly(ethylene glycol) induces the formation of a new, optically active, spirally twisted structure of these molecules ("re-entrant" cholesteric structure (rest-A structure)). Cooling of this dispersion up to 22 °C is accompanied by the formation of an additional "re-entrant" cholesteric structure (rest-B). Modification of particles of the ds DNA dispersion (with rest-B structure) by replacing Na cations by multi-charged Gd cations results in the third " re-entrant" structure (rest-C) despite a high density packing of ds nucleic acid molecules.
在这项工作中，我们报告了在具有双链 (ds) DNA 分子的六方排列的液晶分散颗粒中观察到的新的扭曲（胆甾型样）结构。在渗透压（聚乙二醇浓度）高的水盐溶液中形成的 DNA 分散体加热到 80°C 会诱导这些分子形成新的、光学活性的螺旋扭曲结构（“再进入”胆甾型结构（rest-A 结构））。将该分散体冷却至 22°C 会伴随着形成额外的“再进入”胆甾型结构（rest-B）。通过用多电荷 Gd 阳离子取代 Na 阳离子来修饰具有 rest-B 结构的 ds DNA 分散体的颗粒，尽管 ds 核酸分子的高密度堆积，但会导致第三个“再进入”结构（rest-C）。
Zotero 插件