Department of Chemistry, College of Chemistry and Chemical Engineering, The MOE Key Laboratory of Spectrochemical Analysis and Instrumentation, and iChEM, Xiamen University, 361005, Xiamen, China.
Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, 361005, Xiamen, China.
Nat Commun. 2019 Aug 9;10(1):3610. doi: 10.1038/s41467-019-11539-5.
The natural DNA double helix consists of two strands of nucleotides that are held together by multiple hydrogen bonds. Here we propose to build an artificial double helix from fragments of two strands connected by covalent linkages therein, but with halogen bonding as the driving force for self-assembling the fragments to the double helix. We succeed in building such a double helix in both solution and solid state, by using a bilateral N-(p-iodobenzoyl)alanine based amidothiourea which in its folded cis-form allows double and crossed C-I···S halogen bonds that lead to right- or left-handed double helix when the two alanine residues are of the same L,L- or D,D-configuration. The double helix forms in dilute CHCN solution of the micromolar concentration level, e.g., 5.6 μM from 2D NOESY experiments and exhibits a high thermal stability in solution up to 75 °C, suggesting cooperative and thereby strong intermolecular double crossed halogen bonding that makes the double helix stable. This is supported by the observed homochiral self-sorting in solution.
天然 DNA 双螺旋由两条核苷酸链组成，这些核苷酸链通过多个氢键结合在一起。在这里，我们提议从通过共价键连接的两条链的片段构建人工双螺旋，但将卤键用作将片段自组装成双螺旋的驱动力。我们通过使用双边 N-(对碘苯甲酰基)丙氨酸基酰胺硫脲成功地在溶液和固态中构建了这样的双螺旋，在其折叠的顺式构象中，允许双交叉 C-I···S 卤键，当两个丙氨酸残基具有相同的 L,L-或 D,D-构型时，导致右手或左手双螺旋。双螺旋在稀 CHCN 溶液中形成，例如，从 2D NOESY 实验中得出 5.6 μM，并且在溶液中表现出高达 75°C 的高热稳定性，表明协同且因此强的分子间双交叉卤键使双螺旋稳定。这得到了在溶液中观察到的同手性自分类的支持。
